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Back Pain – Invasive Procedures

Number: 0016

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Policy

Scope of Policy

This Clinical Policy Bulletin addresses invasive procedures for back pain.

Medical Necessity

Aetna considers any of the following injections or procedure medically necessary for the treatment of back pain; provided that only one invasive modality or procedure will be considered medically necessary at a time.
1. Facet joint injections
  1. An initial facet injection (intra-articular and medial branch block) from C2-3 to L5-S1 is considered medically necessary for the diagnosis of facet pain in persons with severe chronic neck and back pain when the following criteria are met:
    1. Member has symptoms suggestive of facet joint syndrome (symptoms of facet joint syndrome include absence of radiculopathy, pain that is aggravated by extension, rotation or lateral bending of the spine and is not typically associated with any neurological deficits); and
    2. Facet mediated pain is confirmed by provocative testing on physical examination (to confirm that pain is exacerbated by extension and rotation); and
    3. Imaging studies suggest no other obvious cause of pain (such as fracture, tumor, infection, or significant extraspinal lesion); and
    4. Pain limits daily activities; and
    5. Pain has lasted more than 3 months; and
    6. Pain has persisted despite six or more weeks of conservative treatment (including, systemic medications, and/or physical therapy); and
    7. Radiofrequency facet neurolysis is being considered.
  2. Injection of no more than three (3) facet joint levels are considered medically necessary during the same session/procedure. These may be performed bilaterally during the same session for a total of up to six injections.
  3. A second diagnostic facet injection (intraarticular and medial branch block) is considered medically necessary to confirm the validity of the clinical response to the initial facet injection when it is administered at the same level as the initial facet injection, and where the initial facet injection produced a positive response (i.e., resulted in an 80% relief of facet mediated pain for at least the expected minimum duration of the effect of the local anesthetic). If the initial injection did not produce a positive response, a second diagnostic injection is considered not medically necessary.
  Additional sets of facet injections or medial branch blocks at the same levels and side are considered experimental, investigational, or unproven because they have no proven value.
  
  Aetna considers diagnostic facet joint injections not medically necessary where radiofrequency facet neurolysis is not being considered.
  
  Diagnostic facet joint injections are considered experimental, investigational, or unproven for neck and back pain with untreated radiculopathy.
  
  Facet joint injections are considered experimental, investigational, or unproven as therapy for back and neck pain and for all other indications because their effectiveness for these indications has not been established. Note: Facet joint injections (intra-articular and medial branch blocks) containing corticosteroids are considered therapeutic injections.
  
  Aetna considers ultrasound guidance of facet injections experimental, investigational, or unproven because of insufficient evidence of its effectiveness.
2. Trigger point injections
  
  Aetna considers trigger point injections of normal saline, corticosteroids and/or local anesthetics medically necessary for treating members with chronic neck or back pain or myofascial pain syndrome when all of the following selection criteria are met:
  1. Conservative treatment such as bed rest, exercises, heating or cooling modalities, massage, and pharmacotherapies such as non-steroidal anti-inflammatory drugs (NSAIDS), muscle relaxants, non-narcotic analgesics, should have been tried and failed, and
  2. Symptoms have persisted for more than 3 months, and
  3. Trigger points have been identified by palpation; and
  4. Trigger point injections are not administered in isolation, but are provided as part of a comprehensive pain management program, including physical therapy, patient education, psychosocial support, and oral medication where appropriate.
  A trigger point is defined as a specific point or area where, if stimulated by touch or pressure, a painful response will be induced. A set of trigger point injections means injections in several trigger points in one sitting.
  
  Up to 4 sets of injections are considered medically necessary to diagnose the origin of a patient’s pain and achieve a therapeutic effect; additional sets of trigger point injections are not considered medically necessary if no clinical response is achieved. It is not considered medically necessary to repeat injections for this indication more frequently than every 7 days.
  
  Once a diagnosis is established and a therapeutic effect is achieved, it is rarely considered medically necessary to repeat trigger point injections more frequently than once every 2 months. Repeated injections extending beyond 12 months may be reviewed for continued medical necessity.
  
  Trigger point injections are considered experimental, investigational, or unproven for all other indications because their effectiveness for indications other than the ones listed above has not been established.
  
  Aetna considers ultrasound or electromyography (EMG) guidance of trigger point injections experimental, investigational or unproven because of insufficient evidence of its effectiveness.
  
  For acupuncture and dry needling, see CPB 0135 – Acupuncture and Dry Needling.
3. Sacroiliac joint injections
  1. Aetna considers sacroiliac joint injections medically necessary to relieve pain associated with lower lumbosacral disturbances in members who meet all of the following criteria:
    1. Member has sacroiliac joint (SIJ) pain for greater than 3 months; and
    2. Member has pain at or close to the posterior superior iliac spine (PSIS) with possible radiation into buttocks, posterior thigh, or groin and can point to the location of pain (Fortin Finger Test); and
    3. Member has at least 3 of 5 physical examination maneuvers specific for SI joint pain:
      1. Compression
      2. Posterior Pelvic Pain Provocation test – P4 (Thigh Thrust)
      3. Patrick’s test (Fabere)
      4. Sacroiliac distraction test
      5. Gaenslen’s test; and
    4. Other causes of low back pain have been ruled out, including lumbar disc degeneration, lumbar disc herniation, lumbar spondylolisthesis, lumbar spinal stenosis, lumbar facet degeneration, and lumbar vertebral body fracture; and
    5. Member has tried 6 weeks of adequate forms of conservative treatment with little or no response, including pharmacotherapy (e.g., NSAIDS), activity modification, and active therapy (including physical therapy where appropriate); and
    6. The injections are not used in isolation, but are provided as part of a comprehensive pain management program, including physical therapy, education, psychosocial support, and oral medication where appropriate.
  2. Up to 2 therapeutic / diagnostic sacroiliac injections are considered medically necessary to diagnose the member’s pain and achieve a therapeutic effect. It is not considered medically necessary to repeat these therapeutic / diagnostic injections more frequently than once every 7 days.
  3. Additional therapeutic sacroiliac injections are considered medically necessary if the member has improvement in lower back pain numeric rating scale (NRS) of at least 70% of the pre-injection NRS score after fluoroscopic or CT controlled injection of local anesthetic with or without steroid into affected SI joint. If the member experiences less than a 70% reduction of pain for the expected duration of the anesthetic, additional sacroiliac joint injections are not considered medically necessary.
  4. Once the diagnosis is established, up to four therapeutic sacroiliac injections, repeated no more frequently than once every 7 days, are considered medically necessary every 12 months.
  Ultrasound guidance of sacroiliac joint injections is considered not medically necessary.
  
  Sacroiliac joint injections are considered experimental, investigational, or unproven for all other indications because their effectiveness for indications other than the ones listed above has not been established.
4. Interlaminar epidural injections
  
  Aetna considers interlaminar epidural injections of corticosteroid preparations (e.g., Depo-Medrol), with or without added anesthetic agents, medically necessary for the following:
  1. In the outpatient setting for management of members with radiculopathy or sciatica when all of the following are met:
    1. Pain is radicular in nature (radicular signs may include, but are not limited to, a positive straight leg raise or a dermatomal pattern of sensory loss). Note: In low back pain, radicular means pain and/or numbness that radiates below the knee; in neck pain, it is pain, numbness or weakness in the shoulder, arm, wrist, or hand; and
    2. Intraspinal tumor or other space-occupying lesion, or non-spinal origin for pain, has been ruled out as the cause of pain:
    3. Member has failed to improve after 4 or more weeks of conservative treatments (e.g., rest, systemic analgesics, physical therapy); and
    4. Interlaminar epidural injections are provided as part of a comprehensive pain management program, which includes physical therapy, patient education, psychosocial support, and oral medications, where appropriate.
  2. Additional interlaminar epidural injections, if the initial injection resulted in at least two of the following for at least two weeks:
    1. A 50 % or greater relief in pain; and
    2. Increase in the level of function/physical activity (e.g., return to work); and
    3. Reduction in the use of pain medication and/or additional medical services such as physical therapy/chiropractic care; and
    4. The interlaminar epidural injections are provided as part of a comprehensive pain management program, which includes physical therapy, patient education, psychosocial support, and oral medications.
    Additional epidural injections are not considered medically necessary if these criteria are not met.
  3. No more than one interlaminar epidural injection is considered medically necessary per session:
    1. More than one interlaminar epidural injection in a single region per session is considered not medically necessary.
    2. Interlaminar epidural injection of more than one region per session is considered not medically necessary.
    Repeat epidural injections more frequently than every two weeks are not considered medically necessary.
  4. A total of up to 3 interlaminar epidural injections per region, per episode of pain are considered medically necessary in 6 months, and up to four interlaminar epidural steroid injections per region (ie, cervical, thoracic, lumbar) per rolling 12-month period are considered medically necessary, only upon return of pain and/or deterioration in function and only when responsiveness to prior injections has occurred (ie, the individual should have at least a 50% reduction in pain and/or symptoms for two weeks).
    
    Additional interlaminar epidural injections per region per rolling 12-month period are considered not medically necessary; and experimental, investigational, or unproven because they have no proven value.
  Aetna considers ultrasound guidance of epidural injections experimental, investigational, or unproven because of insufficient evidence of its effectiveness.
  
  Interlaminar epidural injections of corticosteroid preparations, with or without added anesthetic agents, are considered experimental, investigational, or unproven for all other indications (e.g., non-specific low back pain [LBP] and failed back syndrome) because their effectiveness for indications other than the ones listed above has not been established.
  
  For transforaminal epidural injections, see CPB 0722 – Transforaminal Epidural Injections.
5. Non-pulsed radiofrequency facet denervation
  
  Aetna considers non-pulsed radiofrequency facet denervation (also known as facet neurotomy, facet rhizotomy, or articular rhizolysis) medically necessary for treatment of members with intractable cervical or back pain with or without sciatica in the outpatient setting when all of the following are met:
  1. Member has experienced severe pain limiting activities of daily living for at least 6 months; and
  2. Member has had no prior spinal fusion surgery at the level to be treated; and
  3. Neuroradiologic studies are negative or fail to confirm disc herniation; and
  4. Member has no significant narrowing of the vertebral canal or spinal instability requiring surgery; and
  5. Member has tried and failed six or more weeks of conservative treatments such as bed rest, back supports, physiotherapy, correction of postural abnormality, as well as pharmacotherapies (e.g., anti-inflammatory agents, analgesics, and muscle relaxants); and
  6. The member has two positive diagnostic facet joint injections (intraarticular or medial branch blocks) at the level to be treated, as evidenced by at least 80% relief of facet mediated pain for at least the expected minimum duration of the effect of the local anesthetic used.
  When performing radiofrequency joint denervations/ablations, it may be necessary to perform the procedure at the same level(s) bilaterally; however, radiofrequency ablation of no more than three levels are considered medically necessary during the same session/procedure.
  
  Provided that greater than 50% pain relief is obtained for at least twelve weeks, further facet denervation procedures should be at intervals of at least six months per level per side, at a maximum of twice per rolling calendar year. Only 1 treatment procedure per level per side is considered medically necessary in a 6-month period.
  
  Non-pulsed radiofrequency facet denervation is considered experimental, investigational, or unproven for all other indications because its effectiveness for indications other than the ones listed above has not been established.
  
  See also CPB 0735 – Pulsed Radiofrequency.
6. Spinal Fixation
  
  Aetna considers pedicle screws medically necessary for posterior spinal fusion (see CPB 0743 – Spinal Surgery: Laminectomy and Fusion).
  
  Aetna considers the use of interspinous or interlaminar distraction or stabilization devices with or without lumbar laminectomy and/or fusion experimental, investigational, or unproven.
  
  Aetna considers CoFix for interlaminar/interspinous stabilization experimental, investigational, or unproven.
7. Intervertebral body fusion devices
  
  Aetna considers intervertebral body fusion devices (synthetic spine cages/spacers) (see Appendix) medically necessary for the following:
  1. Use with allograft or autogenous bone graft in members who meet criteria for lumbar spinal fusion as outlined in CPB 0743 – Spinal Surgery: Laminectomy and Fusion and for thoracic fusion;
  2. Synthetic spine cages/spacers for cervical fusion for members who meet criteria in CPB 0743 – Spinal Surgery: Laminectomy and Fusion with any the following indications for use of a synthetic cervical cage/spacer:
    1. Cervical corpectomy (removal of half or more of vertebral body, not mere removal of osteophytes and minor decompression) in the treatment of one of the following:
      1. For tumors involving one or more vertebrae, or
      2. Greater than 50% compression fracture of vertebrae, or
      3. Retropulsed bone fragments, or
      4. Symptomatic central canal stenosis caused by vertebral body pathology (such as due to fracture, tumor or congenital or acquired deformity of the vertebral body).
    2. Cervical fusion for pseudarthrosis in persons with prior fusion; or
    3. For adjacent level disease that has developed in persons with a prior cervical fusion involving a plate, in order to avoid dissection for plate removal when a stand-alone cage/spacer is being used.
    Spine cages are otherwise not considered medically necessary for cervical fusion because they have not been proven more effective than bone graft for this indication.
    
    Spine cages are considered experimental, investigational, or unproven for indications other than fusion because their effectiveness for indications other than those listed above has not been established.
  3. Expandable cages are considered medically necessary for members who meet criteria for fusion in CPB 0743 – Spinal Surgery: Laminectomy and Fusion and who meet either of the following criteria:
    1. At L2-S1; or
    2. For members with osseous defects at the fusion site (i.e., voids or gaps in bone due to trauma, surgical resection, or congenital defects).
    Expandable cages are considered experimental, investigational, or unproven for all other indications.
8. Percutaneous polymethylmethacrylate vertebroplasty (PPV), kyphoplasty, or Spinejack System
  
  Aetna considers percutaneous polymethylmethacrylate vertebroplasty (PPV), kyphoplasty, or SpineJack System medically necessary for members with persistent, debilitating pain in the thoracic or lumbar vertebral bodies resulting from any of the following:
  1. Multiple myeloma; or
  2. Painful and/or aggressive hemangiomas; or
  3. Painful vertebral eosinophilic granuloma; or
  4. Painful, debilitating osteoporotic acute or subacute collapse/compression fractures (proven not to be chronic on recent imaging); or
  5. Primary malignant neoplasm of bone or bone marrow; or
  6. Secondary osteolytic metastasis, excluding sacrum and coccyx, but including cervical;
  And when all of the following criteria have been met:
  1. The pain is localized to the level of the pathology being treated; and
  2. Other causes of pain such as spinal stenosis or herniated intervertebral disk have been ruled out by computed tomography or magnetic resonance imaging; and
  3. The affected vertebra has not been extensively destroyed and is at least 1/3 of its original height with intact posterior cortex;
  And for painful, debilitating osteoporotic acute or subacute collapse/compression fractures (proven not to be chronic on recent imaging):
  1. The affected vertebra has at least 25 % (1/4) height loss/compression, but not been extensively destroyed and is at least 1/3 of its original height with intact posterior cortex; and
  2. Maximum of 3 vertebral fractures per procedure; and
  3. Severe debilitating pain or loss of mobility that cannot be relieved by a minimum of 6 weeks of optimal non-invasive therapy that includes physical therapy, bracing and/or oral medications; and
  4. There needs to be documentation for continuum of care for an evaluation of bone mineral density and osteoporosis education for subsequent treatment as indicated and instructed to take part in an osteoporosis prevention/treatment program.
  All other indications for these procedures are considered experimental, investigational, or unproven.
9. Lateral (including extreme [XLIF], extra and direct lateral [DLIF]) interbody fusion
  
  Aetna considers lateral (including extreme [XLIF], extra and direct lateral [DLIF]) interbody fusion an acceptable method of performing a medically necessary anterior interbody fusion. See CPB 0743 – Spinal Surgery: Laminectomy and Fusion.
10. Coccygectomy
  
  Aetna considers coccygectomy medically necessary for individuals with coccygodynia who have tried and failed to respond to 6 months of conservative management.
11. Vertebral body replacement spacers
  
  Aetna considers vertebral body replacement spacers (e.g., AVS AL PEEK Spacer) medically necessary for vertebral body replacement used in spine surgery for persons with a collapsed, damaged or unstable vertebral body resected or excised during total and partial vertebrectomy procedures due to tumor or trauma (vertebral body replacement should not be confused with Interspinous distraction devices (spacers) (e.g., X-Stop)).
12. Minimally invasive transforaminal lumbar interbody fusion with direct visualization
  
  Aetna considers minimally invasive transforaminal lumbar interbody fusion with direct visualization medically necessary when criteria are met in CPB 0743 – Spinal Surgery: Laminectomy and Fusion.
13. Cementoplasty
  
  Aetna considers cementoplasty medically necessary for individuals with bone pain from pelvic bone metastases with reduced mobility and have failed conventional pain treatments (e.g., acetaminophen, non-steroidal anti-inflammatory drugs, and opioids). For “cementoplasty” for vertebral indications, see section on vertebroplasty.
14. Sacroiliac joint fusion
  
  Aetna considers minimally invasive arthrodesis of the sacroiliac joint (e.g., iFuse) medically necessary for sacroiliac joint syndrome interfering with activities of daily living when all of the following criteria are met:
  1. Adults 18 years of age or older with sacroiliac joint (SIJ) pain for greater than 6 months (or greater than 18 months for pregnancy induced pelvic girdle pain): and
  2. Diagnosis of the SI joint as the primary pain generator based on all of the following:
    1. Member has pain at or close to the posterior superior iliac spine (PSIS) with possible radiation into buttocks, posterior thigh, or groin and can point to the location of pain (Fortin Finger Test); and
    2. Member has at least 3 of 5 physical examination maneuvers specific for SI joint pain:
      1. Compression
      2. Posterior Pelvic Pain Provocation test – P4 (Thigh Thrust)
      3. Patrick’s test (Fabere)
      4. Sacroiliac distraction test
      5. Gaenslen’s test; and
    3. Other causes of low back pain have been ruled out, including lumbar disc degeneration, lumbar disc herniation, lumbar spondylolisthesis, lumbar spinal stenosis, lumbar facet degeneration, and lumbar vertebral body fracture;
      1. Clinician has documented that other neighboring motion segments have been evaluated and ruled out as potential pain generators, including diagnostic testing with facet/medial branch blocks and or interlaminar epidural injections, as appropriate based on the member’s presentation; and
      2. Member has had recent (within 6 months) diagnostic imaging studies that include all of the following:
        
        Plain X-rays and/or cross sectional imaging of the pelvis (CT or MRI) that excludes the presence of destructive lesions (e.g. tumor, infection), acute fracture or inflammatory arthropathy that would not be properly addressed by SIJ fusion; and
        
        Plain X-rays of the pelvis including the ipsilateral hip to exclude potential concomitant hip pathology; and
        
        Cross-sectional imaging (e.g. CT or MRI) of the lumbar spine to exclude potential concomitant neural compression or other degenerative conditions; and
    4. Sacroiliac pathology is not caused by autoimmune disease (e.g. ankylosing spondylitis) and/or neoplasia (e.g. benign or malignant tumor) and/or crystal arthropathy; and
    5. Member has improvement in lower back pain numeric rating scale (NRS) of at least 70% of the pre injection NRS score after two separate fluoroscopic or CT controlled injection of local anesthetic (and at least one injection must be therapeutic and include a steroid) into affected SI joint within the past year. These injections must have been isolated to only the SI joint, so if they were combined with other injections at the same time (e.g., hip, trochanteric bursa, or lumbar spine) they could not be used to meet this criterion; and
  3. Baseline lower back pain score of at least 5 on 0-10 point NRS; and
  4. Member should have tried 6 months of adequate forms of conservative treatment with little or no response, including pharmacotherapy (e.g., NSAIDS), activity modification, and at least three months of formal in-person physical therapy in the past year; and
  5. Radiologic evidence of SI joint degeneration on imaging; and
  6. Member should be nicotine-free (including smoking, use of tobacco products, and nicotine replacement therapy) for at least 1 year prior to surgery. For persons with recent nicotine use, documentation of nicotine cessation should include a lab report (not surgeon summary) showing blood or urinary nicotine level of less than or equal to 10 ng/ml (or urinary cotinine levels of less than or equal to 10 ng/ml) drawn within 6 weeks prior to surgery .
  Open sacroiliac joint fusion is considered medically necessary for sacroiliac joint infection, tumor involving the sacrum, and sacroiliac pain due to severe traumatic injury where a trial of an external fixator is successful in providing pain relief.
  
  Sacroiliac joint fusions are considered experimental, investigational, or unproven for all other indications because their effectiveness for indications other than the ones listed above has not been established.
15. Intramuscular or intravenous injection of ketorolac tromethamine (Toradol)
  
  Aetna considers intramuscular or intravenous injection of ketorolac tromethamine (Toradol) medically necessary for the short-term (up to 5 days) treatment of adults with acute back pain and/or neck pain.
16. The Spinal System-X (Corus)
  
  The Spinal System-X (corus) is a supply and not an implant, and therefore is covered as part of the global surgical fee and not separately reimbursable.
For intercostal nerve blocks, see CPB 0863 – Nerve Blocks.
Experimental, Investigational, or Unproven

The following are considered experimental, investigational, or unproven because of insufficient evidence of their effectiveness for these indications:
1. AccuraScope procedure;
2. AnchorKnot Tissue Approximation Kit (Anchor Orthopedics) for lumbar discectomy;
3. Annulus repair devices (Xclose Tissue Repair System, Barricaid, Disc Annular Repair Technology (DART) System);
4. BacFast HD for isolated facet fusion;
5. Biomet Aspen fusion system (an interlaminar fixation device) (see Appendix);
6. Chemical ablation (including but not limited to alcohol, phenol, or sodium morrhuate) of facet joints;
7. Chymopapain chemonucleolysis, for all indications, including the following (not an all-inclusive list):
  - Acute LBP alone
  - Cauda equina syndrome
  - For herniated discs
  - Multiple back operations (failed back surgery syndrome)
  - Neurologic disease (e.g., multiple sclerosis)
  - Pregnancy
  - Profound or rapidly progressive neurologic deficit
  - Sciatica due to a herniated disc
  - Sequestered disc fragment
  - Severe spinal stenosis
  - Severe spondylolisthesis
  - Spinal cord tumor
  - Spinal instability
  - When performed with chondroitinase ABC or agents other than chymopapain;
8. Coccygeal ganglion (ganglion impar) block for coccydynia, pelvic pain, and all other indications;
9. Cooled radiofrequency ablation (e.g., Coolief) for facet denervation;
10. Cryoablation (cryoanesthesia, cryodenervation, cryoneurolysis, or cryosurgery) for the treatment of lumbar facet joint pain;
11. Deuk Laser Disc Repair;
12. Devices for annular repair (e.g., Inclose Surgical Mesh System);
13. Direct visual rhizotomy (extradural transection or avulsion of other spinal nerve) for the treatment of chronic low back pain;
14. DiscoGel (intradiscal alcohol injection) for the treatment of back and neck pain;
15. Discseel procedure (regenerative spine procedure) for the treatment of back pain;
16. Dynamic (intervertebral) stabilization (e.g., BioFlex, CD Horizon Agile Dynamic Stabilization Device, DSS Dynamic Soft Stabilization System, Dynabolt Dynamic Stabilization System, Dynesys Spinal System, Graf ligamentoplasty/Graf artificial ligament, Isobar Spinal System, NFix, Satellite Spinal System, Stabilimax NZ Dynamic Spine Stabilization System, and the Zodiak DynaMo System);
17. Endoscopic disc decompression, ablation, or annular modulation using the DiscFX System;
18. Endoscopic laser foraminoplasty, endoscopic foraminotomy, laminotomy, and rhizotomy (endoscopic radiofrequency ablation);
19. Endoscopic transforaminal diskectomy;
20. Epidural fat grafting during lumbar decompression laminectomy/discectomy;
21. Epidural injections of lytic agents (e.g., hyaluronidase, hypertonic saline) or mechanical lysis in the treatment of adhesive arachnoiditis, epidural fibrosis, failed back syndrome, or other indications;
22. Epidural steroid injections for the treatment of non-radicular low back pain;
23. Epiduroscopy (also known as epidural myeloscopy, epidural spinal endoscopy, myeloscopy, and spinal endoscopy) for the diagnosis and treatment of intractable LBP or other indications;
24. Facet chemodenervation/chemical facet neurolysis;
25. Facet joint allograft implants (NuFix facet fusion, TruFuse facet fusion)
26. Facet joint implantation (Total Posterior-element System (TOPS) (Premia Spine), Total Facet Arthroplasty System (TFAS) (Archus Orthopedics), ACADIA Facet Replacement System (Facet Solutions/Globus Medical);
27. Far lateral microendoscopic diskectomy (FLMED) for extra-foraminal lumbar disc herniations or other indications;
28. Fluoroscopic guidance for trigger point injection;
29. Hardware injections/blocks;
30. Injection of steroid into the ilio-lumbar ligament for the treatment of low back pain (LBP);
31. Interlaminar lumbar instrumented fusion (ILIF);
32. Interspinous and interlaminar distraction devices (see Appendix);
33. Interspinous fixation devices (Benefix Interspinous Fixation System, CD HORIZON SPIRE Plate, PrimaLOK SP, SP-Fix Spinous Process Fixation Plate, and Stabilink interspinous fixation device) for spinal stenosis or other indications (see Appendix);
34. Intracept System (intra-osseous basivertebral nerve ablation) for the treatment of low back pain, and neck pain;
35. Intradiscal injections of notochordal cell-derived matrix for the treatment of intervertebral disc disease;
36. Intradiscal injection of platelet-rich plasma;
37. Intradiscal, paravertebral, or epidural oxygen or ozone injections;
38. Intradiscal steroid injections;
39. Intramuscular steroid injection for the treatment of back pain, neck pain
40. Intravenous administration of corticosteroids, lidocaine, magnesium, or vitamin B12 (cyanocobalamin) as a treatment for back pain and neck pain;
41. ION procedure (Ion Facet Screw System);
42. Khan kinetic treatment (KKT);
43. Laser facet denervation;
44. Least invasive lumbar decompression interbody fusion (LINDIF);
45. Magnetic resonance imaging-guided focused ultrasound (MRgFUS) for the treatment of lumbar facet joint pain;
46. Microendoscopic discectomy (MED; same as lumbar endoscopic discectomy utilizing microscope) procedure for decompression of lumbar spine stenosis, lumbar disc herniation, or other indications;
47. Microsurgical anterior foraminotomy for cervical spondylotic myelopathy or other indications;
48. Minimally invasive/endoscopic cervical laminoforaminotomy for cervical radiculopathy/lateral and foraminal cervical disc herniations or other indications;
49. Minimally invasive lumbar decompression (MILD) procedure (percutaneous laminotomy/laminectomy (interlaminar approach) for decompression of neural elements under indirect image guidance) for lumbar canal stenosis or other indications;
50. Minimally invasive thoracic discectomy for the treatment of back pain;
51. Minimally invasive endoscopic transforaminal lumbar interbody fusion (endoscopic MITLIF; same as endoscopic MAST fusion) for lumbar disc degeneration and instability or other indications;
52. OptiMesh grafting system;
53. Percutaneous cervical and lumbar diskectomy;
54. Percutaneous endoscopic diskectomy with or without laser (PELD) (also known as arthroscopic microdiskectomy or Yeung Endoscopic Spinal Surgery System [Y.E.S.S.]);
55. Percutaneous lumbar discectomy (manual or automated) for treatment of degenerative disc disease;
56. Piriformis muscle resection and other surgery for piriformis syndrome;
57. Platelet-rich plasma for facet joint injections;
58. Posterior intrafacet implants (e.g., DTRAX Cervical Cage) for posterior cervical fusion;
59. Psoas compartment block for lumbar radiculopathy or myositis ossification;
60. Puborectalis and iliococcygeus trigger point injections for the treatment of pelvic pain;
61. Racz procedure (epidural adhesiolysis with the Racz catheter) for the treatment of members with adhesive arachnoiditis, epidural adhesions, failed back syndrome from multiple previous surgeries for herniated lumbar disk, or other indications;
62. Radiofrequency denervation for sacroiliac joint pain;
63. Radiofrequency lesioning of dorsal root ganglia for back pain;
64. Radiofrequency lesioning of terminal (peripheral) nerve endings for back pain;
65. Radiofrequency/pulsed radiofrequency ablation of trigger point pain;
66. Sacroiliac ligament injection for the treatment of unspecified dorsalgia;
67. Sacroplasty for osteoporotic sacral insufficiency fractures and other indications;
68. Tendon and/or tendon sheath injections for the spine;
69. Tendon sheath injections for the treatment of back pain;
70. Therapeutic facet joint injections;
71. Total Facet Arthroplasty System (TFAS) for the treatment of spinal stenosis;
72. Ultrasound guidance of epidural injections;
73. Ultrasound guidance of facet injections;
74. Ultrasound or electromyography (EMG) guidance of trigger point injections;
75. Vesselplasty (e.g., Vessel-X).
Policy Limitations and Exclusions
1. Laser:
  
  Clinical studies have not established a clinically significant benefit of use of a laser over a scalpel in spinal surgery. No additional benefit will be provided for the use of a laser in spinal surgery.
2. Microscope and endoscope:
  
  Use of a microscope or endoscope is considered an integral part of the spinal surgery and not separately reimbursable.
Related CMS Coverage Guidance

This Clinical Policy Bulletin (CPB) supplements but does not replace, modify, or supersede existing Medicare Regulations or applicable National Coverage Determinations (NCDs) or Local Coverage Determinations (LCDs). The supplemental medical necessity criteria in this CPB further define those indications for services that are proven safe and effective where those indications are not fully established in applicable NCDs and LCDs. These supplemental medical necessity criteria are based upon evidence-based guidelines and clinical studies in the peer-reviewed published medical literature. The background section of this CPB includes an explanation of the rationale that supports adoption of the medical necessity criteria and a summary of evidence that was considered during the development of the CPB; the reference section includes a list of the sources of such evidence. While there is a possible risk of reduced or delayed care with any coverage criteria, Aetna believes that the benefits of these criteria – ensuring patients receive services that are appropriate, safe, and effective – substantially outweigh any clinical harms.

Code of Federal Regulations (CFR):

42 CFR 417; 42 CFR 422; 42 CFR 423.

Internet-Only Manual (IOM) Citations:

CMS IOM Publication 100-02, Medicare Benefit Policy Manual; CMS IOM Publication 100-03 Medicare National Coverage Determination Manual.

Medicare Coverage Determinations:

Centers for Medicare & Medicaid Services (CMS), Medicare Coverage Database [Internet]. Baltimore, MD: CMS; updated periodically. Available at: Medicare Coverage Center. Accessed November 7, 2023.
Related Policies
1. CPB 0135 – Acupuncture and Dry Needling
2. CPB 0411 – Bone and Tendon Graft Substitutes and Adjuncts
3. CPB 0602 – Intradiscal Procedures
4. CPB 0722 – Transforaminal Epidural Injections
5. CPB 0735 – Pulsed Radiofrequency
6. CPB 0743 – Spinal Surgery: Laminectomy and Fusion
7. CPB 0863 – Nerve Blocks

Table:

CPT Codes /HCPCS Codes/ICD-10 Codes

Code Code Description

Coccygectomy:

CPT codes covered if selection criteria are met:

27080 Coccygectomy, primary

ICD-10 codes covered if selection criteria are met:

M53.3 Sacrococcygeal disorders, not elsewhere classified [for individuals with coccygodynia who have tried and failed to respond to 6 months of conservative management]

Facet joint injections [not covered for intradiscal and/or paravertebral oxygen/ozone injection]:

CPT codes covered if selection criteria are met:

64490 Injection(s), diagnostic or therapeutic agent, paravertebral facet (zygapophyseal) joint (or nerves innervating that joint) with image guidance (fluoroscopy or CT), cervical or thoracic; single level 64491 second level 64492 third and any additional level(s) level 64493 Injection(s), diagnostic or therapeutic agent, paravertebral facet (zygapophyseal) joint (or nerves innervating that joint) with image guidance (fluoroscopy or CT), lumbar or sacral; single level 64494 second level 64495 third and any additional level(s) level

CPT codes not covered for indications listed in the CPB:

0213T Injection(s), diagnostic or therapeutic agent, paravertebral facet (zygapophyseal) joint (or nerves innervating that joint) with ultrasound guidance, cervical or thoracic; single level + 0214T second level + 0215T third and any additional level(s) 0216T Injection(s), diagnostic or therapeutic agent, paravertebral facet (zygapophyseal) joint (or nerves innervating that joint) with ultrasound guidance, lumbar or sacral; single level + 0217T second level + 0218T third and any additional level(s) 0232T Injection(s), platelet rich plasma, any site, including image guidance, harvesting and preparation when performed

Other CPT codes related to the CPB:

72275 Epidurography, radiological supervision and interpretation 76942 Ultrasonic guidance for needle placement (eg, biopsy, aspiration, injection, localization device), imaging supervision and interpretation 77002 Fluoroscopic guidance for needle placement (eg, biopsy, aspiration, injection, localization device) 77021 Magnetic resonance guidance for needle placement (eg, for biopsy, needle aspiration, injection, or placement of localization device) radiological supervision and interpretation

Other HCPCS codes related to the CPB:

J0702 Injection, betamethasone acetate 3 mg and betamethasone sodium phosphate 3 mg J1020 Injection, methylprednisolone acetate, 20 mg J1030 Injection, methylprednisolone acetate, 40 mg J1040 Injection, methylprednisolone acetate, 80 mg J1094 Injection, dexamethasone acetate, 1 mg J1100 Injection, dexamethasone sodium phosphate, 1mg J1700 Injection, hydrocortisone acetate, up to 25 mg J1710 Injection, hydrocortisone sodium phosphate, up to 50 mg J1720 Injection, hydrocortisone sodium succinate, up to 100 mg J2650 Injection, prednisolone acetate, up to 1 ml J2920 Injection, methylprednisolone sodium succinate, up to 40 mg J2930 Injection, methylprednisolone sodium succinate, up to 125 mg J3300 Injection, triamcinolone acetonide, preservative free, 1 mg J3301 Injection, triamcinolone acetonide, not otherwise specified, 10 mg J3302 Injection, triamcinolone diacetate, per 5mg J3303 Injection, triamcinolone hexacetonide, per 5mg Q9951, Q9958 – Q9967 High and low osmolar contrast material

ICD-10 codes covered if selection criteria are met:

M53.0 – M53.1 Cervicocranial – cervicobrachial syndrome M53.81 – M53.83 Other specified dorsopathies [cervical region] M54.2 Cervicalgia M54.6 Pain in thoracic spine M54.30 – M54.59 Sciatica and lumbago M54.9 Dorsalgia, unspecified [backache]

ICD-10 codes not covered for indications listed in the CPB:

C41.2 Malignant neoplasm of vertebral column C41.4 Malignant neoplasm of pelvic bones, sacrum and coccyx C79.51 Secondary malignant neoplasm of bone [vertebral column] D16.6 Benign neoplasm of vertebral column D16.8 Benign neoplasm of pelvic bones, sacrum and coccyx D48.0 Neoplasm of uncertain behavior of bone and articular cartilage [vertebral column] D49.2 Neoplasm of unspecified behavior of bone, soft tissue, and skin [vertebral column] M46.20 – M46.28 Osteomyelitis of vertebra M46.30 – M46.39 Infection of intervertebral disc (pyogenic) M80.08xA – M80.08xS Age-related osteoporosis with current pathological fracture, vertebra(e) M80.88xA – M80.88xS Other osteoporosis with current pathological fracture, vertebra(e) M84.38xA – M84.38xS Stress fracture, other site [vertebrae] M84.48xA – M84.48xS Pathological fracture, other site [vertebrae] M84.58xA – M84.58xS Pathological fracture in neoplastic disease, other specified site [vertebrae] M84.68xA – M84.68xS Pathological fracture in other disease, other site [vertebrae] S12.000A – S12.9xxS Fracture of cervical vertebra and other parts of neck S22.000A – S22.089S Fracture of thoracic vertebra S32.000A – S32.059S Fracture of lumbar vertebra S32.10xA – S32.19xS Fracture of sacrum

Ganglion Nerve Block:

CPT codes not covered for indications listed in the CPB:

64450 Injection, anesthetic agent; other peripheral nerve or branch [coccygeal ganglion (ganglion impar) block]

ICD-10 codes not covered for indications listed in the CPB:

M53.3 Sacrococcygeal disorders, not elsewhere classified [coccygodynia]

Trigger point Injections:

CPT codes covered if selection criteria are met:

20552 Injection(s); single or multiple trigger point(s), 1 or 2 muscles(s) [no repeats more than every 7 days, up to four sets to diagnose and achieve therapeutic effect, no additional sets if no clinical response, once diagnosed and therapeutic effect achieved, no repeats more than once every two months and beyond 12 months requires clinical review] 20553 single or multiple trigger point(s), 3 or more muscles(s) [no repeats more than every 7 days, up to four sets to diagnose and achieve therapeutic effect, no additional sets if no clinical response, once diagnosed and therapeutic effect achieved, no repeats more than once every two months and beyond 12 months requires clinical review]

CPT codes not covered for indications listed in the CPB:

76942 Ultrasonic guidance for needle placement (eg, biopsy, aspiration, injection, localization device), imaging supervision and interpretation 77002 Fluoroscopic guidance for needle placement (eg, biopsy, aspiration, injection, localization device) (List separately in addition to code for primary procedure) 95873 Electrical stimulation for guidance in conjunction with chemodenervation (List separately in addition to code for primary procedure) 95874 Needle electromyography for guidance in conjunction with chemodenervation (List separately in addition to code for primary procedure)

Other CPT codes related to the CPB:

77021 Magnetic resonance guidance for needle placement (eg, for biopsy, needle aspiration, injection, or placement of localization device) radiological supervision and interpretation 97001 – 97139 Physical medicine and rehabilitation modalities and therapeutic procedures

Other HCPCS codes related to the CPB:

E0200 – E0239 Heat/cold application S9117 Back school, per visit

ICD-10 codes covered if selection criteria are met:

M54.50 – M54.59 Low back pain M79.10 – M79.18 Myalgia

ICD-10 codes not covered for indications listed in the CPB:

R10.2 Pelvic and perineal pain

Sacroiliac joint injections:

CPT codes covered if selection criteria are met:

27096 Injection procedure for sacroiliac joint, arthrography and/or anesthetic/steroid [up to two injections to diagnose and achieve therapeutic effect, no repeats more than once every 7 days, no additional injections more once every two months or beyond 12 months] 64451 Injection(s), anesthetic agent(s) and/or steroid; nerves innervating the sacroiliac joint, with image guidance (ie, fluoroscopy or computed tomography)

CPT codes not covered for indications listed in the CPB:

20550 Injection(s); single tendon sheath, or ligament, aponeurosis (eg, plantar “fascia”) [Sacroiliac ligament injection] 76942 Ultrasonic guidance for needle placement (eg, biopsy, aspiration, injection, localization device), imaging supervision and interpretation

Other CPT codes related to the CPB:

77003 Fluoroscopic guidance and localization of needle or catheter tip for spine or paraspinous diagnostic or therapeutic injection procedures (epidural, subarachnoid or sacroilliac joint), including neurolytic agent destruction

HCPCS codes covered if selection criteria are met:

G0260 Injection procedure for sacroiliac joint; provision of anesthetic, steroid and/or other therapeutic agent, with or without arthrography

Other HCPCS codes related to the CPB:

G0259 Injection procedure for sacroiliac joint; arthrography

ICD-10 codes covered if selection criteria are met:

M54.30 – M54.59 Sciatica and lumbago [more than 3 months duration and part of a comprehensive pain management program, including physical therapy, patient education, psychosocial support, and oral medication where appropriate]

ICD-10 codes not covered for indications listed in the CPB:

M43.16 Spondylolisthesis, lumbar region M47.896 Other spondylosis, lumbar region [lumbar facet degeneration] M48.061 – M48.062 Spinal stenosis, lumbar region M51.26 Other intervertebral disc displacement, lumbar region M51.36 Other intervertebral disc degeneration, lumbar region M54.9 Dorsalgia, unspecified S32.000A – S32.059S Fracture of lumbar vertebra

Epidural injections of corticosteroid preparations:

CPT codes covered if selection criteria are met:

62320 Injection(s), of diagnostic or therapeutic substance(s) (eg, anesthetic, antispasmodic, opioid, steroid, other solution), not including neurolytic substances, including needle or catheter placement, interlaminar epidural or subarachnoid, cervical or thoracic; without imaging guidance 62321 Injection(s), of diagnostic or therapeutic substance(s) (eg, anesthetic, antispasmodic, opioid, steroid, other solution), not including neurolytic substances, including needle or catheter placement, interlaminar epidural or subarachnoid, cervical or thoracic; with imaging guidance (ie, fluoroscopy or CT) 62322 Injection(s), of diagnostic or therapeutic substance(s) (eg, anesthetic, antispasmodic, opioid, steroid, other solution), not including neurolytic substances, including needle or catheter placement, interlaminar epidural or subarachnoid, lumbar or sacral (caudal); without imaging guidance 62323 Injection(s), of diagnostic or therapeutic substance(s) (eg, anesthetic, antispasmodic, opioid, steroid, other solution), not including neurolytic substances, including needle or catheter placement, interlaminar epidural or subarachnoid, lumbar or sacral (caudal); with imaging guidance (ie, fluoroscopy or CT) 62324 Injection(s), including indwelling catheter placement, continuous infusion or intermittent bolus, of diagnostic or therapeutic substance(s) (eg, anesthetic, antispasmodic, opioid, steroid, other solution), not including neurolytic substances, interlaminarepidural or subarachnoid, cervical or thoracic; without imaging guidance 62325 Injection(s), including indwelling catheter placement, continuous infusion or intermittent bolus, of diagnostic or therapeutic substance(s) (eg, anesthetic, antispasmodic, opioid, steroid, other solution), not including neurolytic substances, interlaminar epidural or subarachnoid, cervical or thoracic; with imaging guidance (ie, fluoroscopy or CT) 62326 Injection(s), including indwelling catheter placement, continuous infusion or intermittent bolus, of diagnostic or therapeutic substance(s) (eg, anesthetic, antispasmodic, opioid, steroid, other solution), not including neurolytic substances, interlaminar epidural or subarachnoid, lumbar or sacral (caudal); without imaging guidance 62327 Injection(s), including indwelling catheter placement, continuous infusion or intermittent bolus, of diagnostic or therapeutic substance(s) (eg, anesthetic, antispasmodic, opioid, steroid, other solution), not including neurolytic substances, interlaminar epidural or subarachnoid, lumbar or sacral (caudal); with imaging guidance (ie, fluoroscopy or CT) 64479 Injection(s), anesthetic agent and/or steroid, transforaminal epidural, with imaging guidance (fluoroscopy or CT); cervical or thoracic, single level +64480 each additional level (List separately in addition to code for primary procedure) 64483 Injection(s), anesthetic agent and/or steroid, transforaminal epidural, with imaging guidance (fluoroscopy or CT); lumbar or sacral, single level +64484 each additional level (List separately in addition to code for primary procedure)

Other CPT codes related to the CPB:

72125 – 72133 Computed tomography, spine 72141 – 72158 Magnetic resonance (eg, proton) imaging, spinal canal and contents 72275 Epidurography, radiological supervision and interpretation 97161-97168 Physical therapy evaluations

Other HCPCS codes related to the CPB:

J1020 Injection, methylprednisone acetate, 20 mg J1030 Injection, methylprednisone acetate, 40 mg J1040 Injection, methylprednisone acetate, 80 mg

ICD-10 codes covered if selection criteria are met:

M47.20 – M47.28 Other spondylosis with radiculopathy M50.10 – M50.13 Cervical disc disorder with radiculopathy M51.14 – M51.17 Intervertebral disc disorders with radiculopathy M53.0 – M53.1 Cervicocranial – cervicobrachial syndrome M53.81 – M53.83 Other specified dorsopathies [cervical region] M54.10 – M54.18 Radiculopathy M54.2 Cervicalgia M54.30 – M54.59 Sciatica and lumbago M54.6 Pain in thoracic spine M54.9 Dorsalgia, unspecified

ICD-10 codes not covered for indications listed in the CPB:

Chymopapain chemonucleolysis:

CPT codes covered if selection criteria are met:

62292 Injection procedure for chemonucleolysis, including discography, intervertebral disc, single or multiple levels, lumbar

Other CPT codes related to the CPB:

62302 – 62305 Myelography via lumbar injection, including radiological supervision and interpretation 72125 – 72133 Computed tomography, spine 72141 – 72158 Magnetic resonance (eg, proton) imaging, spinal canal and contents 72240 – 72270 Myelography of spine

ICD-10 codes not covered for indications listed in the CPB:

C41.2 Malignant neoplasm of vertebral column C41.4 Malignant neoplasm of pelvic bones, sacrum, and coccyx C70.1 Malignant neoplasm of spinal meninges C72.0 Malignant neoplasm of spinal cord C79.31 Secondary malignant neoplasm of brain C79.49 Secondary malignant neoplasm of other parts of nervous system [includes spinal cord] C79.51 – C79.52 Secondary malignant neoplasm of bone and bone marrow D16.6 Benign neoplasm of vertebral column [excludes sacrum and coccyx] D16.8 Benign neoplasm of pelvic bones, sacrum, and coccyx D32.1 Benign neoplasm of spinal meninges D33.4 Benign neoplasm of spinal cord D42.0 – D42.9 Neoplasm of uncertain behavior of meninges D43.0 – D43.2 Neoplasm of uncertain behavior of brain D43.4 Neoplasm of uncertain behavior of spinal cord D49.7 Neoplasm of unspecified behavior of endocrine glands and other parts of nervous system G00.0 – G99.8 Diseases of the nervous system G83.4 Cauda equina syndrome M43.06 – M43.08 Spondylolysis, lumbar, lumbosacral, sacral and sacrococcygeal, region M43.10 – M43.19 Spondylolisthesis [acquired] M43.27 – M43.28M53.2×7 – M53.2x8M53.87 – M53.88 Disorders of sacrum M43.8×9 Other specified deforming dorsopathies, site unspecified M48.00 – M48.01M48.03 – M48.08 Spinal stenosis, other than cervical M48.02 Spinal stenosis, cervical region M50.00 – M50.03 Cervical disc disorder with myelopathy M50.20 – M50.23 Other cervical disc displacement M51.04 – M51.05 Thoracic, thoracolumbar intervertebral disc disorder with myelopathy M51.06 – M51.07 Intervertebral disc disorders with myelopathy, lumbar/lumbosacral region M51.24 – M51.25 Other thoracic, thoracolumbar disc displacement M51.26 – M51.27 Other intervertebral disc displacement, lumbar/lumbosacral regions M53.2×7 – M53.2×8 Spinal instabilities, lumbosacral, sacral, sacrococcygeal region M54.03 – M54.09, M62.830 Other symptoms referable to back M54.30 – M54.32 Sciatica [due to herniated disc] M54.50 – M54.59 Low back pain [lumbago] M54.6 Pain in thoracic spine M54.89 – M54.9 Other and unspecified dorsalgia M96.1 Postlaminectomy syndrome, not elsewhere classified O01.9 – O94 Complications of pregnancy, childbirth, and the puerperium Q76.2 Congenital spondylolisthesis R29.810 – R29.898 Other symptoms and signs involving the nervous and musculoskeletal systems Z34.00 – Z34.93 Encounter for supervision of normal pregnancy

Percutaneous lumbar discectomy or laser-assisted disc decompression (LADD):

CPT codes not covered if selection criteria are met:

62287 Decompression procedure, percutaneous, of nucleus pulposus of intervertebral disc, any method, single or multiple levels, lumbar (eg, manual or automated percutaneous discectomy, percutaneous laser discectomy)

Other CPT codes related to the CPB:

62267 Percutaneous aspiration within the nucleus pulposus, intervertebral disc, or paravertebral tissue for diagnostic purposes 62303 – 62305 Myelography via lumbar injection, including radiological supervision and interpretation 63001 – 63091 Laminectomy, discectomy and related procedures (eg, decompression of spinal cord) 63185 – 63190 Laminectomy with rhizotomy 72125 – 72133 Computed tomography, spine 72141 – 72158 Magnetic resonance (eg, proton) imaging, spinal canal and contents 72240 – 72270 Myelography of spine 77002 Fluoroscopic guidance for needle placement (eg, biopsy, aspiration, injection, localization device)

HCPCS codes not covered for indications listed in the CPB:

G0276 Blinded procedure for lumbar stenosis, percutaneous image-guided lumbar decompression (PILD) or placebo-control, performed in an approved coverage with evidence development (CED) clinical trial

Other HCPCS codes related to the CPB:

C2614 Probe, percutaneous lumbar discectomy

ICD-10 codes not covered if selection criteria are met::

M51.06 – M51.07 Intervertebral disc disorder with myelopathy, lumbar/lumbosacral region M51.26- M51.27 Other intervertebral disc displacement, lumbar/lumbosacral regions M51.35 Other intervertebral disc degeneration, thoracolumbar region M51.36 Other intervertebral disc degeneration, lumbar region M51.37 Other intervertebral disc degeneration, lumbosacral region

Minimally Invasive Lumbar Decompression (MILD):

CPT codes not covered for indications listed in the CPB:

0274T Percutaneous laminotomy/laminectomy (intralaminar approach) for decompression of neural elements, (with or without ligamentous resection, discectomy, facetectomy and/or foraminotomy) any method under indirect image guidance (eg, fluoroscopic, CT), with or without the use of an endoscope, single or multiple levels, unilateral or bilateral; cervical or thoracic 0275T lumbar

Radiofrequency facet denervation:

CPT codes covered if selection criteria are met:

64633 Destruction by neurolytic agent, paravertebral facet joint nerve(s), with imaging guidance (fluoroscopy or CT); cervical or thoracic, single facet joint [not covered for cooled radiofrequency ablation] 64634 cervical or thoracic, each additional facet joint (List separately in addition to code for primary procedure) [not covered for cooled radiofrequency ablation] 64635 lumbar or sacral, single facet joint [not covered for cooled radiofrequency ablation] 64636 lumbar or sacral, each additional facet joint (List separately in addition to code for primary procedure) [not covered for cooled radiofrequency ablation]

CPT codes not covered for indications listed in the CPB:

64625 Radiofrequency ablation, nerves innervating the sacroiliac joint, with image guidance (ie, fluoroscopy or computed tomography)

Other CPT codes related to the CPB:

22548 – 22812 Arthrodesis, vertebra 62302 – 62305 Myelography via lumbar injection, including radiological supervision and interpretation 64479 – 64484 Injection, anesthetic agent and/or steroid, transforaminal epidural 72125 – 72133 Computed tomography, spine 72141 – 72158 Magnetic resonance (eg, proton) imaging, spinal canal and contents 72240 – 72270 Myelography of spine 97001 – 97139 Physical medicine and rehabilitation modalities and therapeutic procedures

Other HCPCS codes related to the CPB:

L0112 – L0999 Orthotic devices-spinal

ICD-10 codes covered if selection criteria are met:

M53.0 – M53.1 Cervicocranial – cervicobrachial syndrome M53.81 – M53.83 Other specified dorsopathies [cervical region] M54.2 Cervicalgia M54.30 – M54.59 Sciatica and lumbago M54.6 Pain in thoracic spine M54.9 Dorsalgia, unspecified [backache]

ICD-10 codes not covered for indications listed in the CPB:

M43.27 – M43.29, M53.2×7 – M53.2×8, M53.87 – M53.88 Disorders of sacrum M50.00 – M51.9 Intervertebral disc disorders M51.A0 – M51.A5 Intervertebral annulus fibrosus defect Z98.1 Arthrodesis status [vertebra]

Transforaminal lumbar interbody fusion:

CPT codes covered if selection criteria are met:

22630 Arthrodesis, posterior interbody technique, including laminectomy and/or discectomy to prepare interspace (other than for decompression), single interspace; lumbar 22632 Arthrodesis, posterior interbody technique, including laminectomy and/or discectomy to prepare interspace (other than for decompression), single interspace; each additional interspace (List separately in addition to code for primary procedure)

ICD-10 codes covered if selection criteria are met:

C41.2 Malignant neoplasm of vertebral column, excluding sacrum and coccyx C70.1 Malignant neoplasm of spinal meninges C79.31 – C79.32 Secondary malignant neoplasm of brain and spinal cord C79.49 Secondary malignant neoplasm of other parts of nervous system C79.51 – C79.52 Secondary malignant neoplasm of bone and bone marrow D32.1 Benign neoplasm of spinal meninges D33.4 Benign neoplasm of spinal cord D42.0 – D42.9 Neoplasm of uncertain behavior of meninges D43.0 – D43.2, D43.4 Neoplasm of uncertain behavior of brain and spinal cord D48.0 Neoplasm of uncertain behavior of bone and articular cartilage G06.1 Intraspinal abscess and granuloma M40.50 – M40.57 Lordosis, unspecified M41.00 – M41.35, M41.80 – M41.9 Scoliosis M43.00 – M43.19 Spondylolysis and spondylolisthesis M46.20 Osteomyelitis of vertebra, site unspecified M46.30 Infection of intervertebral disc (pyogenic), site unspecified M48.061 – M48.07 Spinal stenosis, lumbar and lumbosacral region M48.50x+ – M48.58x+, M80.08x+, M84.48x+, M84.58x+, M84.68x+ Pathologic fracture of vertebrae M86.18 Other acute osteomyelitis, other site [spinal] M86.28 Subacute osteomyelitis, other site [spinal] M86.68 Other chronic osteomyelitis, other site [spinal] M96.0 Pseudoarthrosis after fusion or arthrodesis M96.5 Postradiation scoliosis Numerous options Nonunion of fracture [Codes not listed due to expanded specificity] Q76.2 Congenital spondylolisthesis S31.000+ Unspecified open wound of lower back and pelvis without penetration into retroperitoneum S32.000+ – S32.059+ Fracture of lumbar vertebra S33.100+ – S33.141+ Subluxation and dislocation of lumbar vertebra S34.101+ – S34.129+ Other and unspecified injury of lumbar spinal cord Z98.1 Arthrodesis status

Intervertebral body fusion devices:

CPT codes covered if selection criteria are met:

22853 Insertion of interbody biomechanical device(s) (eg, synthetic cage, mesh) with integral anterior instrumentation for device anchoring (eg, screws, flanges), when performed, to intervertebral disc space in conjunction with interbody arthrodesis, each interspace (List separately in addition to code for primary procedure) 22854 Insertion of intervertebral biomechanical device(s) (eg, synthetic cage, mesh) with integral anterior instrumentation for device anchoring (eg, screws, flanges), when performed, to vertebral corpectomy(ies) (vertebral body resection, partial or complete) defect, in conjunction with interbody arthrodesis, each contiguous defect (List separately in addition to code for primary procedure) 22859 Insertion of intervertebral biomechanical device(s) (eg, synthetic cage, mesh, methylmethacrylate) to intervertebral disc space or vertebral body defect without interbody arthrodesis, each contiguous defect (List separately in addition to code for primary procedure)

Other CPT codes related to the CPB:

20936 – 20938 Autograft for spine surgery 63081 – 63082 Vertebral corpectomy

HCPCS codes covered if selection criteria are met:

Synthetic cervical cages/spacers, Spine Cages, Expandable cages – no specific code (not an all-inclusive list):

(e.g., BAK Interbody Fusion System, Ray Threaded Fusion Cage, STALIF stand-alone anterior lumbar fusion cage, carbon fiber cage)

ICD-10 codes covered if selection criteria are met:

C41.2 Malignant neoplasm of vertebral column C79.51 Secondary malignant neoplasm of bone M24.08 Loose body, other site [retropulsed bone fragments] M25.78 Osteophyte, vertebrae [of spine causing spinal cord or nerve root compression, confirmed by imaging studies] [see criteria in CPB 743] M48.02 Spinal stenosis, cervical region [symptomatic central canal stenosis] M50.00 – M50.03 Cervical disc disorders with myelopathy [see criteria in CPB 743] M50.20 – M50.23 Other cervical disc displacement [see criteria in CPB 743] M51.34 – M51.37 Other thoracic, thoracolumbar and lumbosacral intevertebral disc degeneration [see criteria in CPB 743] M54.11 – M54.13 Radiculopathy, cervical region [see criteria in CPB 743] M89.78 Major osseous defect, other site M96.0 Pseudarthrosis after fusion or arthrodesis Q76.2 Congenital spondylolisthesis [see criteria in CPB 743] S12.000A – S12.691S Fracture of cervical vertebra

Percutaneous polymethylmethacrylate vertebroplasty (PPV), kyphoplasty or SpineJack System:

CPT codes covered if selection criteria are met:

22510 – 22511 Percutaneous vertebroplasty (bone biopsy included when performed), 1 vertebral body, unilateral or bilateral injection, inclusive of all imaging guidance; cervicothoracic or lumbosacral 22512 each additional cervicothoracic or lumbosacral vertebral body (List separately in addition to code for primary procedure) 22513 – 22514 Percutaneous vertebral augmentation, including cavity creation (fracture reduction and bone biopsy included when performed) using mechanical device (eg, kyphoplasty), 1 vertebral body, unilateral or bilateral cannulation, inclusive of all imaging guidance; thoracic or lumbar 22515 each additional thoracic or lumbar vertebral body (List separately in addition to code for primary procedure)

Other CPT codes related to the CPB::

77080 Dual-energy X-ray absorptiometry (DXA), bone density study, 1 or more sites; axial skeleton (eg, hips, pelvis, spine) 77085 axial skeleton (eg, hips, pelvis, spine), including vertebral fracture assessment 77086 Vertebral fracture assessment via dual-energy X-ray absorptiometry (DXA)

HCPCS codes covered for indications listed in the CPB:

C1062 Intravertebral body fracture augmentation with implant (e.g., metal, polymer) [spineJack system] C7504 Percutaneous vertebroplasties (bone biopsies included when performed), first cervicothoracic and any additional cervicothoracic or lumbosacral vertebral bodies, unilateral or bilateral injection, inclusive of all imaging guidance C7505 Percutaneous vertebroplasties (bone biopsies included when performed), first lumbosacral and any additional cervicothoracic or lumbosacral vertebral bodies, unilateral or bilateral injection, inclusive of all imaging guidance C7507 Percutaneous vertebral augmentations, first thoracic and any additional thoracic or lumbar vertebral bodies, including cavity creations (fracture reductions and bone biopsies included when performed) using mechanical device (eg, kyphoplasty), unilateral or bilateral cannulations, inclusive of all imaging guidance C7508 Percutaneous vertebral augmentations, first lumbar and any additional thoracic or lumbar vertebral bodies, including cavity creations (fracture reductions and bone biopsies included when performed) using mechanical device (eg, kyphoplasty), unilateral or bilateral cannulations, inclusive of all imaging guidance

ICD-10 codes covered if selection criteria are met:

ICD-10 codes not covered for indications listed in the CPB:

M50.20 – M51.9 Intervertebral disc disorders

Endoscopic Spinal surgery:

Other CPT codes related to the CPB:

62267 Percutaneous aspiration within the nucleus pulposus, intervertebral disc, or paravertebral tissue for diagnostic purposes 62287 Decompression procedure, percutaneous, of nucleus pulposus of intervertebral disc, any method, single or multiple levels, lumbar (eg, manual or automated percutaneous discectomy, percutaneous laser discectomy) 77002 Fluoroscopic guidance for needle placement (eg, biopsy, aspiration, injection, localization device)

Vertebral body replacement spacers (e.g., AVS AL PEEK Spacer):

No specific code

ICD-10 codes covered if selection criteria are met:

M43.8X9 Other specified deforming dorsopathies, site unspecified [damaged or unstable vertebral body resected or excised during total and partial vertebrectomy procedures] M48.50x+ – M48.58x+ Collasped vertebra, not elsewhere classified

Cementoplasty:

CPT codes covered if selection criteria are met:

Cementoplasty – no specific code:

ICD-10 codes covered if selection criteria are met:

C41.4 Malignant neoplasm of pelvic bones, sacrum and coccyx

Intramuscular injection of Ketorolac tromethamine (Toradol):

Other CPT codes related to the CPB:

96372 Therapeutic, prophylactic, or diagnostic injection (specify substance or drug [Toradol] ); subcutaneous or intramuscular

HCPCS codes covered if selection criteria are met:

J1885 Injection, ketorolac tromethamine per 15 mg [Toradol]

ICD-10 codes covered if selection criteria are met:

M54.00- M54.9 Dorsalgia

Experimental and Investigational Interventions for treatment of back pain:

Chronic Back Pain:

CPT codes not covered for indications listed in the CPB:

Direct visual rhizotomy, Discseel procedure, DiscoGel (intradiscal alcohol injection) – no specific code:

0232T Injection(s), platelet rich plasma, any site, including image guidance, harvesting and preparation when performed 20550 Injection(s); single tendon sheath, or ligament, aponeurosis 20551 single tendon origin/insertion 20560 Needle insertion(s) without injection(s); 1 or 2 muscle(s) 20561 Needle insertion(s) without injection(s); 3 or more muscles

Other CPT codes related to the CPB:

96365 – 96368 Intravenous infusion, for therapy, prophylaxis, or diagnosis 96372 Therapeutic, prophylactic, or diagnostic injection (specify substance or drug); subcutaneous or intramuscular

HCPCS codes not covered for indications listed in the CPB:

DART Disc Annular Repair Device, Xclose Tissue Repair System –no specific code C9757 Laminotomy (hemilaminectomy), with decompression of nerve root(s), including partial facetectomy, foraminotomy and excision of herniated intervertebral disc, and repair of annular defect with implantation of bone anchored annular closure device, including annular defect measurement, alignment and sizing assessment, and image guidance; 1 interspace, lumbar [Barricaid] J0702 Injection, betamethasone acetate 3 mg and betamethasone sodium phosphate 3 mg J1020 Injection, methylprednisolone acetate, 20 mg J1030 Injection, methylprednisolone acetate, 40 mg J1040 Injection, methylprednisolone acetate, 80 mg J1094 Injection, dexamethasone acetate, 1 mg J1100 Injection, dexamethasone sodium phosphate, 1 mg J1700 Injection, hydrocortisone acetate, up to 25 mg J1710 Injection, hydrocortisone sodium phosphate, up to 50 mg J1720 Injection, hydrocortisone sodium succinate, up to 100 mg J1885 Injection, ketorolac tromethamine per 15 mg J2001 Injection, lidocaine HCL for intravenous infusion 10 mg J2650 Injection, prednisolone acetate, up to 1 ml J2920 Injection, methylprednisolone sodium succinate, up to 40 mg J2930 Injection, methylprednisolone sodium succinate, up to 125 mg J3300 Injection, triamcinolone acetonide, preservative free, 1 mg J3301 Injection, triamcinolone acetonide, not otherwise specified, 10 mg J3302 Injection, triamcinolone diacetate, per 5 mg J3303 Injection, triamcinolone hexacetonide, per 5 mg J3420 Injection, vitamin B-12 cyanocobalamin, up to 1000 mg J3475 Injection, magnesium sulfate, per 500 mg

ICD-10 codes not covered for indications listed in the CPB:

M54.00- M54.9 Dorsalgia

Magnetic resonance imaging-guided focused ultrasound (MRgFUS):

CPT codes not covered for indications listed in the CPB:

Magnetic resonance imaging-guided focused ultrasound (MRgFUS) –no specific code

ICD-10 codes not covered for indications listed in the CPB:

M54.00 – M54.9 Dorsalgia

Experimental and investigational Interventions for treatment of neck pain:

CPT codes not covered for indications listed in the CPB:

DiscoGel (intradiscal alcohol injection) – no specific code:

Other CPT codes related to the CPB:

96365 – 96368 Intravenous infusion, for therapy, prophylaxis, or diagnosis 96372 Therapeutic, prophylactic, or diagnostic injection (specify substance or drug); subcutaneous or intramuscular

HCPCS codes not covered for indications listed in the CPB:

J0702 Injection, betamethasone acetate 3 mg and betamethasone sodium phosphate 3 mg J1010 Injection, methylprednisolone acetate, 1 mg J1020 Injection, methylprednisolone acetate, 20 mg J1030 Injection, methylprednisolone acetate, 40 mg J1040 Injection, methylprednisolone acetate, 80 mg J1094 Injection, dexamethasone acetate, 1 mg J1100 Injection, dexamethasone sodium phosphate, 1 mg J1700 Injection, hydrocortisone acetate, up to 25 mg J1710 Injection, hydrocortisone sodium phosphate, up to 50 mg J1720 Injection, hydrocortisone sodium succinate, up to 100 mg J1885 Injection, ketorolac tromethamine per 15 mg J2001 Injection, lidocaine hcl for intravenous infusion, 10 mg J2650 Injection, prednisolone acetate, up to 1 ml J2919 Injection, methylprednisolone sodium succinate, 5 mg J2920 Injection, methylprednisolone sodium succinate, up to 40 mg J2930 Injection, methylprednisolone sodium succinate, up to 125 mg J3300 Injection, triamcinolone acetonide, preservative free, 1 mg J3301 Injection, triamcinolone acetonide, not otherwise specified, 10 mg J3302 Injection, triamcinolone diacetate, per 5 mg J3303 Injection, triamcinolone hexacetonide, per 5 mg J3304 Injection, triamcinolone acetonide, preservative-free, extended-release, microsphere formulation, 1 mg J3420 Injection, vitamin B-12 cyanocobalamin, up to 1000 mg J3475 Injection, magnesium sulfate, per 500 mg

ICD-10 codes not covered for indications listed in the CPB:

M54.2 Cervicalgia

Endoscopic transforaminal diskectomy:

CPT codes not covered for indications listed in the CPB:

62287 Decompression procedure, percutaneous, of nucleus pulposus of intervertebral disc, any method utilizing needle based technique to remove disc material under fluoroscopic imaging or other form of indirect visualization, with the use of an endoscope, with discography and/or epidural injection(s) at the treated level(s), when performed, single or multiple levels, lumbar [not covered for endoscopic transforaminal discectomy]

Other CPT codes related to the CPB:

96365 – 96366 Intravenous infusion, for therapy, prophylaxis, or diagnosis (specify substance or drug [magnesium, Toradol and vitamin B12 cyanocobalamin] for the treatment of back pain)

HCPCS codes not covered for indications listed in the CPB:

J1885 Injection, ketorolac tromethamine per 15 mg [Toradol] J3420 Injection, vitamin B-12 cyanocobalamin, up to 1000 mg J3475 Injection, magnesium sulfate, per 500 mg

ICD-10 codes not covered for indications listed in the CPB:

M54.50 – M54.59 Low back pain M54.9 Dorsalgia, unspecified

Minimally Invasive Thoracic diskectomy:

CPT codes not covered for indications listed in the CPB:

22532 Arthrodesis, lateral extracavitary technique, including minimal discectomy to prepare interspace (other than for decompression); thoracic

Percutaneous cervical diskectomy:

Minimally Invasive Lumbar Decompression (MILD):

CPT codes not covered for indications listed in the CPB:

HCPCS codes not covered for indications listed in the CPB:

G0276 Blinded procedure for lumbar stenosis, percutaneous image-guided lumbar decompression (PILD) or placebo-control, performed in an approved coverage with evidence development (CED) clinical trial

ICD codes not covered for indications listed in the CPB:

M51.26 Other intervertebral disc displacement, lumbar region

Epiduroscopy:

Other CPT codes related to the CPB:

62318 Injection, including catheter placement, continuous infusion or intermittent bolus, not including neurolytic substances, with or without contrast (for either localization or epidurography), of diagnostic or therapeutic substance(s) (including anesthetic, antispasmodic, opioid, steroid, other solution), epidural or subarachnoid; cervical or thoracic 62319 lumbar, sacral (caudal) 72275 Epidurography, radiological supervision and interpretation

Epidural injections of lytic agents:

CPT codes not covered for indications listed in the CPB:

62280 Injection/infusion of neurolytic substance (eg, alcohol, phenol, iced saline solutions), with or without other therapeutic substance; subarachnoid Ultrasonic guidance for needle placement (eg, biopsy, aspiration, injection, localization device), imaging supervision and interpretation [not covered for chemical ablation (including but not limited to alcohol, phenol or sodium morrhuate) of facet joints] 62281 epidural, cervical or thoracic [not covered for chemical ablation (including but not limited to alcohol, phenol or sodium morrhuate) of facet joints] 62282 epidural, lumbar, sacral (caudal) [not covered for chemical ablation (including but not limited to alcohol, phenol or sodium morrhuate) of facet joints]

Other CPT codes related to the CPB:

72275 Epidurography, radiological supervision and interpretation

HCPCS codes not covered for indications listed in the CPB:

J3470 Injection, hyaluronidase, up to 150 units J3471 Injection, hyaluronidase, ovine, preservative free, per 1 USP unit (up to 999 USP units) J3472 Injection, hyaluronidase, ovine, preservative free, per 1000 USP units J3473 Injection, hyaluronidase, recombinant, 1 USP unit

ICD-10 codes not covered for indications listed in the CPB:

G03.0 – G03.9 Meningitis due to other and unspecified causes M43.00 – M43.9 Dorsopathies M54.10 Radiculopathy, site unspecified M79.2 Neuralgia and neuritis, unspecified S12.000S – S12.691SS12.9xxS, S22.000S – S22.089SS32.000S – S32.2xxS Fracture of vertebral column, sequela S39.002+ – S39.003+S39.092+ – S39.093+S39.82x+ – S39.83x+S39/92x+ – S39.93x+ Other injuries of other sites of trunk

Intracept System:

CPT codes not covered for indications listed in the CPB:

64628 Thermal destruction of intraosseous basivertebral nerve, including all imaging guidance; first 2 vertebral bodies, lumbar or sacral 64629 Thermal destruction of intraosseous basivertebral nerve, including all imaging guidance; each additional vertebral body, lumbar or sacral (List separately in addition to code for primary procedure)

ICD-10 codes not covered for indications listed in the CPB:

M54.2 Cervicalgia M54.50 – M54.59 Low back pain [chronic]

Intradiscal injections of notochordal cell-derived matrix:

CPT codes not covered for indications listed in the CPB:

Intradiscal injections of notochordal cell-derived matrix – no specific code:

ICD-10 codes not covered for indications listed in the CPB:

M50.00 – M50.93 Cervical disc disorders M51.04 – M51.9 Thoracic, thoracolumbar, and lumbosacral intervertebral disc disorders

Microsurgical anterior foraminotomy:

No specific codes

Other CPT codes related to the CPB:

63075 – 63078 Discectomy, anterior, with decompression of spinal cord and/or nerve root(s), including osteophytectomy

Other HCPCS codes related to the CPB:

S2350 Discectomy, anterior, with decompression of spinal cord and/or nerve root(s), including osteophytectomy; lumbar, single interspace S2351 Discectomy, anterior, with decompression of spinal cord and/or nerve root(s), including osteophytectomy; lumbar, each additional interspace (list separately in addition to code for primary procedure)

Sacroiliac fusion:

CPT codes covered if selection criteria are met:

27278 Arthrodesis, sacroiliac joint, percutaneous, with image guidance, including placement of intra-articular implant(s) (eg, bone allograft[s], synthetic device[s]), without placement of transfixation device 27279 Arthrodesis, sacroiliac joint, percutaneous or minimally invasive (indirect visualization), with image guidance, includes obtaining bone graft when performed, and placement of transfixing device 27280 Arthrodesis, open, sacroiliac joint, including obtaining bone graft, including instrumentation, when performed [may be medically necessary for sacroiliac joint infection, tumor involving the sacrum, and sacroiliac pain due to severe traumatic injury where a trial of an external fixator is successful in providing pain relief]

CPT codes not covered for indications listed in the CPB:

0775T Arthrodesis, sacroiliac joint, percutaneous, with image guidance, includes placement of intra-articular implant(s) (eg, bone allograft(s), synthetic device(s)) 0809T Arthrodesis, sacroiliac joint, percutaneous or minimally invasive (indirect visualization), with image guidance, placement of transfixing device(s) and intraarticular implant(s), including allograft or synthetic device(s)

Other CPT codes related to the CPB:

72200 Radiologic examination, sacroiliac joints; less than 3 views 72202 3 or more views 80323 Alkaloids, not otherwise specified [Blood or Urinary Nicotine] 97001 – 97799 Physical Medicine and Rehabilitation 99406 – 99407 Smoking and tobacco use cessation counseling visit

Other HCPCS codes related to the CPB:

Titanium triangular implants – no specific code:

S4995 Smoking cessation gum S9453 Smoking cessation classes, nonphysician provider, per session

ICD-10 codes covered if selection criteria are met:

C41.4 Malignant neoplasm of pelvic bones, sacrum and coccyx C76.3 Malignant neoplasm of pelvis D16.8 Benign neoplasm of pelvic bones, sacrum and coccyx M01.x8 Direct infection of vertebrae in infectious and parasitic diseases classified elsewhere [sacroiliac joint infection] M02.88 Other reactive arthropathies, vertebrae [sacroiliac joint infection] M46.1 Sacroiliitis, not elsewhere classified [sacroiliac joint syndrome] M53.3 Sacrococcygeal disorders, not elsewhere classified [sacroiliac joint syndrome] M54.17 Radiculopathy, lumbosacral region [due to severe traumatic injury] M54.18 Radiculopathy, sacral and sacrococcygeal region [due to severe traumatic injury] S32.301A – S32.9xxB Sacroiliac injuries

ICD-10 codes not covered for indications listed in the CPB:

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F17.200 – F17.299 Nicotine dependence M11.08 Hydroxyapatite deposition disease, vertebrae [lumbar] M11.18 Familial chondrocalcinosis, vertebrae [lumbar] M11.28 Other chondrocalcinosis, vertebrae [lumbar] M11.88 Other specified crystal arthropathies, vertebrae [lumbar] M43.16 Spondylolisthesis, lumbar region M45.6 Ankylosing spondylitis lumbar region M47.896 Other spondylosis, lumbar region [lumbar facet degeneration] M48.061 – M48.062 Spinal stenosis, lumbar region M51.26 Other intervertebral disc displacement, lumbar region M51.36 Other intervertebral disc degeneration, lumbar region Z72.0 Tobacco use

Sacroplasty:

CPT codes not covered for indications listed in the CPB:

0200T Percutaneous sacral augmentation (sacroplasty), unilateral injection(s), including the use of a balloon or mechanical device, when used, 1 or more needles, includes imaging guidance and bone biopsy, when performed 0201T Percutaneous sacral augmentation (sacroplasty), bilateral injections, including the use of a balloon or mechanical device, when used, 2 or more needles, includes imaging guidance and bone biopsy, when performed

Racz procedure (epidural adhesiolysis with the Racz catheter):

CPT codes not covered for indications listed in the CPB:

62263 Percutaneous lysis of epidural adhesions using solution injection (e.g., hypertonic saline, enzyme) or mechanical means (eg, catheter) including radiologic localization (includes contrast when administered), multiple adhesiolysis sessions; 2 or more days 62264 1 day

Other CPT codes related to the CPB:

72275 Epidurography, radiological supervision and interpretation

Microdiskectomy:

Other CPT codes related to the CPB:

22220 – 22226 Osteotomy of spine, including discectomy, anterior approach 62267 Percutaneous aspiration within the nucleus pulposus, intervertebral disc, or paravertebral tissue for diagnostic purposes 62287 Decompression procedure, percutaneous, of nucleus pulposus of intervertebral disc, any method, single or multiple levels, lumbar (eg, manual or automated percutaneous discectomy, percutaneous laser discectomy) + 69990 Operating microscope 77002 Fluoroscopic guidance for needle placement (eg, biopsy, aspiration, injection, localization device)

Other HCPCS codes related to the CPB:

C2614 Probe, percutaneous, lumbar discectomy S2350 Discectomy, anterior, with decompression of spinal cord and/or nerve root(s), including osteophytectomy; lumbar, single interspace S2351 Discectomy, anterior, with decompression of spinal cord and/or nerve root(s), including osteophytectomy; lumbar, each additional interspace (list separately in addition to code for primary procedure)

Microendoscopic discectomy (MED):

Other CPT codes related to the CPB:

22206 Osteotomy of spine, posterior or posterolateral approach, three columns, one vertebral segment (eg, pedicle/vertebral body subtraction); thoracic 22207 lumbar + 22208 each additional vertebral segment (List separately in addition to code for primary procedure) 22214 Osteotomy of spine, posterior or posterolateral approach, one vertebral segment; lumbar + 22216 each additional vertebral segment (List separately in addition to primary procedure) 22224 Osteotomy of spine, including discectomy, anterior approach, single vertebral segment; lumbar + 22226 each additional vertebral segment (List separately in addition to code for primary procedure) 62287 Aspiration or decompression procedure, percutaneous, of nucleus pulposus of intervertebral disc, any method, single or multiple levels, lumbar (eg, manual or automated percutaneous discectomy, percutaneous laser discectomy) + 69990 Operating microscope 77002 Fluoroscopic guidance for needle placement (eg, biopsy, aspiration, injection, localization device)

Other HCPCS codes related to the CPB:

Intercostal nerve blocks:

CPT codes not covered for indications listed in the CPB:

64420 Injection, anesthetic agent; intercostal nerve single 64421 intercostal nerves, multiple, regional block

ICD-10 codes not covered for indications listed in the CPB:

G54.8 Other nerve root and plexus disorders [intercostal neuritis]

Inter-spinous distraction (X Stop Device, Coflex interspinous stablilization spinal implant, Extensure bone allograft inter-spinous spacer, Eclipse inter-spinous distraction device, and the TOPS System):

CPT codes not covered for indications listed in the CPB:

22867 Insertion of interlaminar/interspinous process stabilization/distraction device, without fusion, including image guidance when performed, with open decompression, lumbar; single level 22868 Insertion of interlaminar/interspinous process stabilization/distraction device, without fusion, including image guidance when performed, with open decompression, lumbar; second level (List separately in addition to code for primary procedure) 22869 Insertion of interlaminar/interspinous process stabilization/distraction device, without open decompression or fusion, including image guidance when performed, lumbar; single level 22870 Insertion of interlaminar/interspinous process stabilization/distraction device, without open decompression or fusion, including image guidance when performed, lumbar; second level (List separately in addition to code for primary procedure) 0202T Posterior vertebral joint(s) arthroplasty (e.g., facet joint[s] replacement) including facetectomy, laminectomy, foraminotomy and vertebral column fixation, with or without injection of bone cement, including fluoroscopy, single level, lumbar spine

HCPCS codes not covered for indications listed in the CPB:

C1821 Interspinous process distraction device (implantable)

Piriformis muscle resection:

No specific codes

CPT codes not covered for indications listed in the CPB:

27006 Tenotomy, abductors and/or extensor(s) of hip, open (separate procedure) 64712 Neuroplasty, major peripheral nerve, arm or leg, open; sciatic nerve [not covered for surgery for piriformis syndrome]

ICD-10 codes not covered for indications listed in the CPB:

G57.00 – G57.03 Lesion of sciatic nerve M25.751 – M25.759 Osteophyte, hip M54.30 – M54.32 Sciatica M70.60 – M70.72 Trochanteric and other bursitis M76.00 – M76.22 Enthesopathies, hip

Radiofrequency denervation for sacroiliac joint pain:

CPT codes not covered for indications listed in the CPB:

27035 Denervation, hip joint, intrapelvic or extrapelvic intrarticular branches of sciatic, femoral, or obturator nerves [not covered when specified as radiofrequency denervation for sacroiliac pain] 64625 Radiofrequency ablation, nerves innervating the sacroiliac joint, with image guidance (ie, fluoroscopy or computed tomography)

ICD-10 codes not covered for indications listed in the CPB:

G57.00 – G57.03 Lesion of sciatic nerve M25.751 – M25.759 Osteophyte, hip M54.14 – M54.17 Radiculopathy, thoracic or lumbosacral region M54.30 – M54.32 Sciatica M70.60 – M70.72 Trochanteric and other bursitis M72.9 Neuralgia and neuritis, unspecified M76.00 – M76.22 Enthesopathies, hip

Facet joint implantation:

CPT codes not covered for indications listed in the CPB:

0219T Placement of a posterior intrafacet implant(s), unilateral or bilateral, including imaging and placement of bone graft(s) or synthetic device(s), single level; cervical 0220T thoracic 0221T lumbar 0222T each additional vertebral segment (List separately in addition to code for primary procedure)

Epidural fat grafting:

Other CPT codes related to the CPB:

15769 Grafting of autologous soft tissue, other, harvested by direct excision (eg, fat, dermis, fascia)

Endoscopic disc decompression:

CPT codes not covered for indications listed in the CPB:

62380 Endoscopic decompression of spinal cord, nerve root(s), including laminotomy, partial facetectomy, foraminotomy, discectomy and/or excision of herniated intervertebral disc, 1 interspace, lumbar

No specific codes:

AccuraScope procedure, ACIS cage (Synthes), Anchor Knot Tissue Approximation Kit, Ancora spacer, Aspen spinous process fixation system, Benefix Interspinous Fixation System, Biomet Aspen fusion system, Brantigan, Brigade anterior plate system, Brigade (Nuvasive), Cambria anterior cervical interbody system, Cavetto cage, Centerpiece plate, Crescent cage, CD HORIZON SPIRE Plate, PrimaLOK SP, and SP-Fix Spinous Process Fixation Plate, Coccygeal ganglion (ganglion impar) blockade for pelvic pain, Degas plate, Deuk Laser Disc Repair, Diamond (Amendia), DiscFX System, Dynamic (intervertebral) stabilization devices – BioFlex, CD Horizon Agile Dynamic Stabilization Device, Dynamic stabilization (e.g., Dynesys Spinal System and the Stabilimax NZ Dynamic Spine Stabilization System), Ebi PEEK optima spacer, Ellipse Occipito-Cervical-Thoracic spinal system, Endoscopic laser foraminoplasty, EOS spinal system (Korean Bone Bank), Epidural ozone, Extreme lateral interbody fusion (XLIF), G surgical plate system T loc, Illico pedicle screw system (Alphatec), IN:C2 spacer, Interlaminiar lumbar instrumented fusion (ILIF), Invizia plate, Kinetic-SL Dynamic Anterior Cervical Plate System, LINDIF, OptiMesh grafting system, Oxygen injection, Psoas compartment block, Radiofrequency lesioning of dorsal root ganglia, Radiofrequency lesioning of terminal (peripheral) nerve endings, Radiofrequency/pulsed radiofrequency ablation of trigger points, Stabilink interspinous fixation device, Total Facet Arthroplasty System, TSRH 3DX pedicle screws (Medtronic), Van Gogh plate, Vesselplasty (e.g., Vessel-X), Yeung Endoscopic Spinal Surgery System, Y.E.S.S., Zeus C cervical spacer, ION procedure (Ion Facet Screw System), Spinal System-X (Corus), CoFix (for interlaminar/interspinous stabilization)

Background

Epidural Steroids

An epidural steroid injection is an injection of long lasting steroid in the epidural space – that is the area which surrounds the spinal cord and the nerves coming out of it. An epidural steroid injection is used to help reduce radicular spinal pain that may be caused by pressure on a spinal nerve root as a result of a herniated disc, degenerative disc disease or spinal stenosis. This treatment is most frequently used for low back pain, though it may also be used for cervical (neck) or thoracic (midback) pain. A combination of an anesthetic and a steroid medication is injected into the epidural space near the affected spinal nerve root with the assistance of fluoroscopy which allows the physician to view the placement of the needle.

Approaches to the epidural space for the injection include:

Caudal –

the epidural needle is placed into the tailbone (coccyx) allowing the treatment of pain which radiates into the lower extremities. This approach is commonly used to treat lumbar radiculopathy after prior surgery in the low back (post-laminectomy pain syndrome).
Cervical –

the epidural needle is placed in the midline in the back of the neck to treat neck pain which is associated with radiation of pain into an upper extremity (cervical radiculopathy).
Interlaminar –

the needle is placed between the lamina of two vertebrae directly from the middle of the back. Also called translaminar, this method accesses the large epidural space overlying the spinal cord, and is the most commonly used approach for cervical, thoracic, and lumbar epidural injections. Medication is delivered to the nerve roots on both the right and left sides of the inflamed area at the same time.
Lumbar –

the epidural needle is placed in the midline in the low back to treat back pain which is associated with radiation into a lower extremity (lumbar radiculopathy).
Thoracic –

the epidural needle is placed in the midline in the upper or middle back.
Transforaminal –

the needle is placed to the side of the vertebra in the neural foramen, just above the opening for the nerve root and outside the epidural space; this method treats one side at a time.

The goal of this treatment is to reduce inflammation and block the spinal nerve roots to relieve radicular pain or sciatica. It can also provide sufficient pain relief to allow the individual to progress with their rehabilitation program.

The efficacy of epidurally administered steroids has been demonstrated without adverse consequence in a large number of patients with reproducible results. In a large number of studies, long-term relief of pain (greater than 3 months) can be achieved in at least 10 to 30% of patients, while short-term relief (less than 1 month) can be achieved in 60 to 100% of patients. Results for cervical pain are somewhat lower than those for lumbar pain. Such therapy is considered under accepted guidelines to be indicated in patients with low back and cervical pain that has not resolved after only a short period of more conservative measures since studies have shown a better response to therapy in patients whose pain is of shorter duration. Even if pain relief is temporary, it may have long-term benefit because it allows initiation of physical therapy or other rehabilitative measures at an earlier stage. Most authors indicate that a limit on number of injections is appropriate, and that most patients will respond with 3 or fewer injections.

The American Academy of Neurology’s assessment on the use of epidural steroid injections in the treatment of radicular lumbosacral pain (Armond et al, 2007) concluded that:

Guidelines from the American Pain Society (Chou et al, 2009) questioned the clinical value of epidural injection for long-term use or for use of non-radicular back pain. A recommendation for epidural steroid injection for patients with symptomatic spinal stenosis was not offered based on insufficient or poor evidence.

Langer-Gould et al (2013) discussed the American Academy of Neurology (AAN)’s top five recommendations in the “Choosing Wisely” campaign promoting high-value neurologic medicine and physician-patient communication. They noted that 1 of the 11 finalist recommendations was “Don’t perform epidural steroid injections to treat non-radicular low back pain”.

Trigger Point Injections

Trigger point injections (TPI) are injections of saline or a local anesthetic, with or without a steroid medication, into a painful area of a muscle that contains the trigger point. The purpose of a TPI is to relax the area of intense muscle spasm, effectively inactivate the trigger point and provide prompt symptomatic pain relief. TPI is the most common interventional technique used in pain medicine.

Trigger points have also been treated with dry needling. For information on dry needling, see the Background section in CPB 0135 – Acupuncture and Dry Needling.

A myofascial trigger point is a discrete focal tenderness, 2-5 mm in diameter that is located in distinct tight bands or knots of skeletal muscle (AHFMR, 2002). When palpated, these hyper-irritable areas cause pain in distant areas, or referred pain zones, which are specific for each trigger point. Trigger point injection, or direct wet needling, involves injection of fluid directly into the trigger point located in the taut muscle band. The main objective of trigger point injection is fast pain relief and elimination of muscle spasm in order to break the pain cycle. This facilitates physical therapy aimed at reducing muscle contracture and increasing range of motion. Trigger point injection is rarely used in isolation but is generally part of a multi-disciplinary approach aimed at treating both the trigger points and reducing all contributing factors (Scott and Guo, 2005; AHFMR, 2002; Sanders et al, 1999). Thus, treatment may also include patient education, psychosocial support, oral medications, and physical therapy to improve the strength and flexibility of the affected musculoskeletal systems. An assessment conducted by the Alberta Heritage Foundation for Medical Research (Scott and Guo, 2005) found that the evidence for the effectiveness of trigger point injections when used as the sole treatment for patients with chronic head, neck, and shoulder pain and whiplash syndrome was inconclusive, regardless of whether sterile water, saline, or botulinum toxin is injected. The assessment found that the combined use of dry needling and trigger point injection with procaine offers no obvious clinical benefit in the treatment of chronic craniofacial pain, while the effectiveness of trigger point injection for the treatment of cervicogenic headache is unknown. In contrast, the assessment found that trigger point injection with lidocaine may be useful in the treatment of joint pain caused by osteoarthritis (Scott and Guo, 2005). The assessment found no proof that triggers point injection is more effective than other less invasive treatments, such as physical therapy and ultrasound, in achieving pain relief, and there is some suggestion that the only advantage of injecting anesthetic into trigger points is that it reduces the pain of the needling process (Scott and Guo, 2005). Usually, approximately 3 treatments are necessary to abolish a trigger point completely (AHFMR, 2002). A number of trigger points may be injected in 1 session, but rarely more than 5. Repeated injections in a particular muscle are not recommended if 2 or 3 previous attempts have been unsuccessful (Alvarez and Rockwell, 2002; Sanders et al, 1999). The pain relief may last for the duration of the anesthetic to many months, depending on the chronicity and severity of the trigger points and the concomitant treatment of perpetuating factors. According to available guidelines, use of trigger point injections should be short-term and part of a comprehensive rehabilitation program. Available guidelines indicate that, while there are a number of uncontrolled case studies using trigger point injections in more acute pain presentations, there is virtually no consistent evidence for its application with chronic non-malignant pain syndrome patients to date (Sanders et al, 1999; AHFMR, 2002).

Botwin and colleagues (2008) noted that myofascial pain is defined as pain that originates from myofascial trigger points in skeletal muscle. It is prevalent in regional musculoskeletal pain syndromes, either alone or in combination with other pain generators. The myofascial pain syndrome is one of the largest groups of under diagnosed and under treated medical problems encountered in clinical practice. Trigger points are commonly seen in patients with myofascial pain which is responsible for localized pain in the affected muscles as well as referred pain patterns. Correct needle placement in a myofascial trigger point is vital to prevent complications and improve efficacy of the trigger point injection to help reduce or relieve myofascial pain. In obese patients, these injections may not reach the target tissue. In the cervico-thoracic spine, a misguided or misplaced injection can result in a pneumothorax. These researchers described an ultrasound-guided trigger point injection technique to avoid this potential pitfall. Office based ultrasound-guided injection techniques for musculoskeletal disorders have been described in the literature with regard to tendon, bursa, cystic, and joint pathologies. For the interventionalist, utilizing ultrasound yields multiple advantages technically and practically, including observation of needle placement in real-time, ability to perform dynamic studies, the possibility of diagnosing musculoskeletal pathologies, avoidance of radiation exposure, reduced overall cost, and portability of equipment within the office setting. To the authors’ knowledge, the use of ultrasound guidance in performing trigger point injection in the cervico-thoracic area, particularly in obese patients, has not been previously reported. A palpable trigger point in the cervico-thoracic musculature was localized and marked by indenting the skin with the tip of a plastic needle cover. The skin was then sterile prepped. Then, using an ultrasound machine with sterile coupling gel and a sterile latex free transducer cover, the musculature in the cervico-thoracic spine where the palpable trigger point was detected was visualized. Then utilizing direct live ultrasound guidance, a 25-gauge 1.5 inch needle connected to a 3-ml syringe was placed into the muscle at the exact location of the presumed trigger point. This guidance helped confirm needle placement in muscle tissue and not in an adipose tissue or any other non-musculature structure. The technique was simple to be performed by a pain management specialist who has ultrasound system training. The authors concluded that ultrasound-guided trigger point injections may help confirm proper needle placement within the cervico-thoracic musculature. The use of ultrasound-guided trigger point injections in the cervico-thoracic musculature may also reduce the potential for a pneumothorax by an improperly placed injection.

Zhou and Wang (2014) stated that myofascial pain syndrome (MPS) is a common chronic pain condition that is characterized by distinct “trigger points”. Despite current treatments with physical therapy, analgesics, anti-depressants and trigger-point injections, myofascial pain remains a challenging chronic pain condition in clinical practice. Botulinum toxin A (BTX-A) can cause prolonged muscle relaxation through inhibition of acetylcholine release. It may offer some advantages over the current treatments for MPS by providing a longer sustained period of pain relief. Despite numerous clinical trials, the efficacy of BTX-A in alleviating MPS is not well-established due to mixed results from recent clinical trials. Active trigger points are associated with referred pain and greatly impact many aspects of activities of daily living, mood, and health status. This review was designed to analyze the clinical trials regarding the efficacy of BTX-A injection of active trigger points as a treatment for MPS. The literature referenced was obtained via a computer search with Google Scholar, PubMed, Medline and Embase. Search terms included “Botulinum toxin”, “myofascial pain”, “trigger points”, “myofascial trigger points”, and “chronic pain”. Additional references were retrieved from the reference list of the reports found via this search. Studies were considered eligible for inclusion if they were double-blinded, randomized, controlled trials evaluating the efficacy of BTX-A injections into trigger points for pain reduction, and if the trigger point selection in the trial included referred pain and/or local twitch response. Open-label studies, case reports, and other non-randomized studies were excluded. A total of 8 trials were found according to the above criteria. There are well-designed clinical trials to support the efficacy of trigger-point injections with BTX-A for MPS. However, further clini cal trials with considerations of minimizing placebo effect, repeated dosing, adequate coverage of trigger points, and using ultrasound confirmation and guidance are required to provide conclusive evidence for BTX-A in the treatment of myofascial pain.

In a prospective, double-blinded, randomized controlled trial, Misirlioglu et al (2015) investigated the differences between local anesthetic (LA) and LA + corticosteroid (CS) injections in the treatment of piriformis syndrome (PS). A total of 57 patients having unilateral hip and/or leg pain with positive FAIR test and tenderness and/or trigger point at the piriformis muscle were evaluated. Out of 50 patients randomly assigned to 2 groups, 47 patients whose pain resolved at least 50% from the baseline after the injection were diagnosed as having PS. The 1st group (n = 22) received 5 ml of lidocaine 2% while the 2nd group (n = 25) received 4 ml of lidocaine 2% + 1 ml of betametazone under the guidance of ultrasound. Outcome measures included Numeric Rating Scale (NRS) and Likert Analogue Scale (LAS). No statistically significant difference (p > 0.05) was detected between the groups in NRS score values at resting (p = 0.814), night (p = 0.830), and in motion (p = 0.145), and LAS values with long duration of sitting (p = 0.547), standing (p = 0.898), and lying (p = 0.326) with evaluations at baseline, 1st week, and 1st and 3rd months after the injection. A statistically highly significant (p < 0.005) reduction of pain was evaluated through NRS scores at resting (p = 0.001), in motion (p = 0.001), and at night (p = 0.001) and LAS values with long duration of sitting (p = 0.001), standing (p = 0.001), and lying (p = 0.001) in both of the groups. The authors concluded that LA injections for the PS were found to be clinically effective. However, addition of CS to LA did not give an additional benefit. The main drawback of this study was its relatively small sample.

a true intra-sheath (group I) or
an extra-sheath (group E) injection under ultrasonographic guidance.

Symptom remission and recurrence rates and recurrence timing did not significantly differ between the groups. Ultrasonography revealed mean (standard deviation) pre-injection A1 pulley thicknesses of 1.1 (0.3) and 1.1 (0.2) mm in groups I and E, respectively. One month after injection, these decreased to 0.7 (0.2) and 0.8 (0.2) mm, respectively (p < 0.05). Furthermore, mean (standard) pre-injection flexor digitorum tendon thickness was 4.1 (0.4) and 4.0 (0.5) mm in groups I and E, respectively, and, 1 mo after injection, decreased to 3.9 (0.3) and 3.8 (0.5) mm, respectively (p < 0.05). However, the difference at each time-point between the 2 groups was not statistically significant. The authors concluded that true intra-sheath injection offered no apparent advantage over extra-sheath injection for treating trigger fingers because both have the same effect on local structures.

UpToDate reviews on “Subacute and chronic low back pain: Nonsurgical interventional treatment” (Chou, 2018) and “Treatment of neck pain” (Isaac, 2017) do not mention ultrasound-guidance as an adjunct for trigger point injections.

Lumbar Laminectomy With or Without Fusion

Laminectomy and laminotomy involve removal of a small part of the bony arches of the spinal canal, called the lamina, which increases the size of the spinal canal. A laminectomy or laminotomy is most commonly performed for a diagnosis of spinal stenosis. During a laminectomy the entire lamina is removed while only a portion of the lamina is removed in a laminotomy. These procedures are also often done with either a discectomy or a foraminectomy/foraminotomy.

Most individuals with acute low back problems spontaneously recover activity tolerance within 4 to 6 weeks of conservative therapy (AHCPR, 1994). Conservative therapy for acute low back pain (LBP) includes:

Avoidance of activities that aggravate pain
Chiropractic manipulation in the first 4 weeks if no radiculopathy
Cognitive support and reassurance that recovery is expected
Education regarding spine biomechanics
Exercise program
Heat/cold modalities for home use
Limited bed rest with gradual return to normal activities
Low impact exercise as tolerated (e.g., walking, swimming, stationary bike)
Non-narcotic analgesics
Pharmacotherapy (e.g., non-narcotic analgesics, non-steroidal anti-inflammatory drugs [NSAIDs] (as second-line choices), avoid muscle relaxants, or only use during the first week, avoid narcotics).

If conservative therapy fails to relieve symptoms of sciatica and radiculopathy and there is strong evidence of dysfunction of a specific nerve root confirmed at the corresponding level by findings demonstrated by CT/MRI, lumbar laminectomy may be proposed as a treatment option. The goal of lumbar laminectomy is to provide decompression of the affected nerve root to relieve the individual’s symptoms. It involves the removal of all or part of the lamina of a lumbar vertebra. The addition of fusion with or without instrumentation is considered when there are concerns about instability.

Decompression With or Without Discectomy for Cauda Equine Syndrome

Cauda equina (“horse’s tail”) is the name given to the lumbar and sacral nerve roots within the dural sac caudal to the conus medullaris. Cauda equina syndrome is usually the result of a ruptured, midline intervertebral disk, most commonly occurring at the L4 to L5 level. However, tumors and other compressive masses may also cause the syndrome. Individuals generally present with progressive symptoms of fecal or urinary incontinence, impotence, distal motor weakness, and sensory loss in a saddle distribution. Muscle stretch reflexes may also be reduced. The presence of urinary retention is the single most consistent finding (Perron and Huff, 2002).

In acute cauda equine syndrome, surgical decompression as soon as possible is recommended. In a more chronic presentation with less severe symptoms, decompression could be performed when medically feasible and should be delayed to optimize the patient’s medical condition; with this precaution, decompression is less likely to lead to irreversible neurological damage (Dawodu, 2005).

Cervical Laminectomy With or Without Fusion

A cervical laminectomy (may be combined with an anterior approach) is sometimes performed when acute cervical disc herniation causes central cord syndrome or in cervical disc herniations refractory to conservative measures. Studies have shown that an anterior discectomy with fusion is the recommended procedure for central or anterolateral soft disc herniation, while a posterior laminotomy-foraminotomy may be considered when technical limitations for anterior access exist (e.g., short thick neck) or when the individual has had prior surgery at the same level (Windsor, 2006).

Discectomy alone is regarded as a technique that most frequently results in spontaneous fusion (70 to 80%). Additional fusion techniques include the use of bone grafts (autograft, allograft or artificial) with or without cages and/or the use of an anterior plate. Based on the clinical evidence, autologous or cadaveric bone grafting, with or without plating, remains the gold standard for cervical fusion. Therefore, use of an intervertebral cage for cervical fusion is considered experimental and investigational. A Cochrane systematic review (2004) reported the results of fourteen studies (n = 939) that evaluated three comparisons of different fusion techniques for cervical degenerative disc disease and concluded that discectomy alone has a shorter operation time, hospital stay, and post-operative absence from work than discectomy with fusion with no statistical difference for pain relief and rate of fusion. The authors concluded that more conservative techniques (discectomy alone, autograft) perform as well or better than allograft, artificial bone, and additional instrumentation; however, the low quality of the trials reviewed prohibited extensive conclusions and more studies with better methodology and reporting are needed.

An assessment by the BlueCross BlueShield Association Technology Evaluation Center (BCBSA, 2014) stated: “The choice of bone material for interbody fusion in [anterior cervical discectomy and fusion] ACDF has important clinical implications. Allograft bone has several drawbacks, including a minute (albeit unproven) risk of infectious disease transmission; possible immunological reaction to the allograft; and possible limited commercial availability of appropriate graft material. In contrast, the use of autograft bone in ACDF has potentially substantial morbidities at the harvest site, generally the iliac crest. These include moderate-to-severe, sometimes prolonged pain; deep infection; adjacent nerve and artery damage; and increased risk of stress fracture. Although there may be slight differences between autograft and allograft sources in the postoperative rate of union, clinical studies have demonstrated similar rates of postoperative fusion (90%-100%) and satisfactory outcomes for single-level, anterior-plated ACDF using either bone source. Thus, the choice of graft material involves a trade-off between the risks specific to autograft harvest versus those specific to use of allograft material.”

A systematic review of randomized controlled trials found no reliable evidence for use of cages over autograft for cervical spinal fusion (Jacobs et al, 2011). Noting that the number of surgical techniques for decompression and anterior cervical interbody fusion (ACIF) for cervical degenerative disc disease has increased, the investigators sought to determine which technique of ACIF gives the best outcome. From a comprehensive search, the investigators selected randomized studies that compared anterior cervical decompression and ACIF techniques, in patients with chronic single- or double-level degenerative disc disease or disc herniation. Risk of bias was assessed using the criteria of the Cochrane back review group. A total of 33 studies with 2,267 patients were included. The major treatments were discectomy alone and addition of an ACIF procedure (graft, cement, cage, and plates). The investigators stated, at best, there was very low-quality evidence of little or no difference in pain relief between the techniques. The investigators found moderate quality evidence for few secondary outcomes. The investigators found that Odom’s criteria were not different between iliac crest autograft and a metal cage (risk ratio [RR]: 1.11; 95% confidence interval [CI]: 0.99-1.24). Bone graft produced more fusion than discectomy (RR: 0.22; 95% CI: 0.17-0.48). Complication rates were not different between discectomy and iliac crest autograft (RR: 1.56; 95% CI: 0.71-3.43). Low-quality evidence was found that iliac crest autograft results in better fusion than a cage (RR: 1.87; 95% CI: 1.10-3.17); but more complications (RR: 0.33; 95% CI: 0.12-0.92). The investigators concluded that, when fusion of the motion segment is considered to be the working mechanism for pain relief and functional improvement, iliac crest autograft appears to be the gold standard. The investigators stated that, when ignoring fusion rates and looking at complication rates, a cage as a gold standard has a weak evidence base over iliac crest autograft, but not over discectomy.

An evidence review by Epstein et al (2012) reached similar conclusions. These researchers (2012) noted that grafting choices available for performing anterior cervical diskectomy/fusion (ACDF) procedures have become a major concern for spinal surgeons, and their institutions. The “gold standard”, iliac crest autograft, may still be the best and least expensive grafting option; it deserves to be reassessed along with the pros, cons, and costs for alternative grafts/spacers. Although single or multilevel ACDF have utilized iliac crest autograft for decades, the implant industry now offers multiple alternative grafting and spacer devices; (allografts, cages, polyether-etherketone (PEEK) amongst others). While most studies have focused on fusion rates and clinical outcomes following ACDF, few have analyzed the “value-added” of these various constructs (e.g. safety/ efficacy, risks/complications, costs). Epstein (2012) found that the majority of studies document 95%-100% fusion rates when iliac crest autograft is utilized to perform single level ACDF (X-ray or computyed tomography [CT] confirmed at 6-12 postoperative months). Although many allograft studies similarly quote 90%-100% fusion rates (X-ray alone confirmed at 6-12 postoperative months), a recent “post hoc analysis of data from a prospective multicenter trial” (Riew KD et. al., CSRS Abstract Dec. 2011; unpublished) revealed a much higher delayed fusion rate using allografts at one year 55.7%, 2 years 87%, and four years 92%. The author found no clinically significant differences in cervical spine fusion outcomes between autograft and cages, despite an up to 10-fold difference in cost among various constructs. The author concluded that iliac crest autograft utilized for single or multilevel ACDF is associated with the highest fusion, lowest complication rates, and significantly lower costs compared with allograft, cages, PEEK, or other grafts. As spinal surgeons and institutions become more cost conscious, we will have to account for the “value added” of these increasingly expensive graft constructs.

Kersten et al (2015) stated that polyetheretherketone (PEEK) cages have been widely used during the past decade in patients with degenerative disorders of the cervical spine. Their radiolucency and low elastic modulus make them attractive attributes for spinal fusion compared with titanium and bone graft. Still, limitations are seen such as pseudoarthrosis, subsidence, and migration of the cages. The authors stated that limited evidence on the clinical outcome of PEEK cages is found in the literature other than noncomparative cohort studies with only a few randomized controlled trials. The authors conducted a systematic evidence review to assess the clinical and radiographic outcome of PEEK cages in the treatment of degenerative disc disorders and/or spondylolisthesis in the cervical spine. The systematic review included all randomized controlled trials and prospective and retrospective nonrandomized comparative studies with a minimum follow-up of 6 months and all noncomparative cohort studies with a long-term follow-up of more than 5 years. The primary outcome variable was clinical performance. Secondary outcome variables consisted of radiographic scores. The MEDLINE, EMBASE, and Cochrane Library databases were searched according to the Preferred Reporting Items of Systematic reviews and Meta-Analyses statement and Metaanalysis Of Observational Studies in Epidemiology guidelines. A total of 223 studies were identified, of which 10 studies were included. These comprised two randomized controlled trials, five prospective comparative trials, and three retrospective comparative trials. The authors found minimal evidence for better clinical and radiographic outcome for PEEK cages compared with bone grafts in the cervical spine. No differences were found between PEEK, titanium, and carbon fiber cages. The authors stated that future studies are needed to improve methodology to minimize bias. Publication of lumbar interbody fusion studies needs to be promoted because differences in clinical and/or radiographic scores are more likely to be demonstrated in this part of the spine.

The Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons and Congress of Neurological Surgeons (Ryken et al, 2009) conducted a systematic review to determine the efficacy of cervical interbody grafting techniques. The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to cervical interbody grafting. Abstracts were reviewed and studies that met the inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons. The authors found that autograft bone harvested from the iliac crest, allograft bone from either cadaveric iliac crest or fibula, or titanium cages and rectangular fusion devices, with or without the use of autologous graft or substitute, have been successful in creating arthrodesis after 1- or 2-level anterior cervical discectomy with fusion (Class II). Alternatives to autograft, allograft, or titanium cages include polyetheretherketone cages and carbon fiber cages (Class III). Polyetheretherketone cages have been used successfully with or without hydroxyapatite for anterior cervical discectomy with fusion. Importantly, recombinant human bone morphogenic protein-2 carries a complication rate of up to 23-27% (especially local edema) compared with 3% for a standard approach. The authors concluded that current evidence does not support the routine use of interbody grafting for cervical arthrodesis. Multiple strategies for interbody grafting have been successful with Class II evidence supporting the use of autograft, allograft, and titanium cages.

The Congress of Neurological Surgeons assessment (Ryken et al, 2009) stated that “class II evidence indicates that either autograft bone harvested from iliac crest, allograft bone from either cadaveric iliac crest or fibula, or titanium cages and rectangular fusion devices, with or without autologous graft or substitute are excellent interbody treatment options for obtaining cervical arthrodesis. There is an expected autograft fusion rate for non-instrumented single-level fusions better than 80% and for 2-level fusion of better than 70%. With allograft, the expected fusion rate for non-instrumented single-level fusion is > 80%, and is > 50% for 2-level fusion. The use of titanium cages carries an expectation of a fusion rate of > 70%, and often > 90% with avoidance of donor site morbidity.” The CNS assessment stated: “In choosing a graft strategy, no single type of graft has not proven consistently superior to the other. Class III evidence suggests that the surgeon consider the increased rate of subsidence with allograft but also understand that subsidence does not correlate with clinical outcome. Class III evidence also suggests that the surgeon factor in the incidence of donor pain and decrease in patient satisfaction reported with the harvest of autograft iliac crest graft.” The assessment stated: “If alternatives to auto- and allograft are preferred, therapeutic options are as follows: PEEK may be considered with or without the use of hydroxyapatite after ACDF. There is an expectation of fusion rates > 90% with fewer complications due to the absence of graft harvesting (Class III). Carbon fiber cages may be considered as well with fusion rates ranging from 55 to 62% in the larger studies (Class III). Polymethyl-methylmethacrylate may be considered to preserve intervertebral distraction after discectomy, but is a poor fusion substrate (Class II). All of the above options appear to have similar clinical outcomes equivalent to the use of bone.” The CNS assessment concluded that, “Given the generally high rates of improved clinical outcome with anterior cervical discectomy and fusion, regardless of methodology, the evaluation of medical-economic factors may play an important role in future studies.”

A Senate Finance Committee Report (2012) focusing on Infuse, one substitute for bone graft, noted that company officials inserted language into studies that promoted the substitute as a better technique than the autograft technique by emphasizing the pain associated with the autograft technique.

Chemonucleolysis

Chemonucleolysis is a procedure that involves the dissolving of the gelatinous cushioning material in an intervertebral disk by the injection of chymopapain or other enzyme. The AHCPR evidence-based guideline on the management of acute back pain and the medical literature supports the use of chemonucleolysis (CNL) with chymopapain as a safe and effective alternative to surgical disc excision in the majority of patients who are candidates for surgery for intractable sciatica due to herniated nucleus pulposus (HNP). Chemonucleolysis involves the enzymatic degradation of the nucleus pulposus, and has been shown to be more effective than percutaneous discectomy since it can be successfully performed for protruded and extruded discs, just as long as the herniated disc material is still in continuity with the disc of its origin. Following CNL, in many cases, relief of sciatica is immediate; however, in up to 30% of patients, maximal relief of symptoms may take up to 6 weeks. The overall success rate for CNL in long-term follow-up (7 to 20 years) in 3,130 patients from 13 contributors averaged 77% (range of 71 to 93%), the same as that reported for surgical discectomy. In the United States, CNL is approved by the Food and Drug Administration (FDA) for use in the lumbar spine only.

On January 27, 2003, the sale and distribution of chymopapain was discontinued in the U.S. after the company producing it decided to cease its sale worldwide.

Facet Joint Blocks and Medial Branch Blocks

Facet injections, also known as facet blocks, are injections of a local anesthetic, with or without a steroid medication, into the facet joints or around the nerve supply (the medial branch nerve) to the joints. Facet injections may be given for diagnostic purposes to determine if the facet joint is the source of pain or it may be performed to treat facet pain that has previously been detected. The injections are fluoroscopically guided. If the pain is relieved, the physician will know that the facet joint appears to be the source of pain. Facet denervation may also follow a successful diagnostic facet block.

Degenerative changes in the posterior lumber facet joints have been established as a source of LBP that may radiate to the leg. Pain impulses from the medial branches of lumbar dorsal rami can be interrupted by blocking these nerves with anesthetic (facet block) or coagulating them with a radiofrequency wave (radiofrequency facet denervation). Typically, facet joint blocks are performed as a part of a work-up for back or neck pain (Wagner, 2003). Pain relief following a precise injection of local anesthetic confirms the facet joint as the source of pain. Based on the outcome of a facet joint nerve block, if the patient gets sufficient relief of pain but the pain recurs, denervation of the facet joint may be considered.

A number of uncontrolled studies have suggested positive effects of facet injections on chronic back pain (Wagner, 2003). However, randomized controlled trials (RCTs) have failed to demonstrated a benefit. A well-designed trial (n = 101) of patients who responded to a local anesthetic injection into the facet joint published in the New England Journal of Medicine found no difference in the likelihood of pain relief following randomization to glucocorticoid or saline facet joint injection at either 1 or 3 months post injection (Carette et al, 1991). A higher proportion of patients in the steroid injection group reported marked improvement after 6 months (46% versus 15%), but the benefit was attenuated after controlling for co-interventions used in the steroid group, and there is no biologic explanation for a delayed benefit from steroids. A second, smaller trial found no differences between steroid and/or bupivacaine injection compared to placebo (Lilius et al, 1989).

A number of systematic evidence reviews and evidence-based guidelines have evaluated the literature on facet injections for chronic back pain. Guidelines from the American Pain Society (Chou et al, 2009) stated: “We found good or fair evidence that … facet joint injection … are not effective.” Guidelines from the American Association of Neurological Surgeons (Resnick et al, 2005) state: “Facet injections are not recommended as long-term treatment for chronic low-back pain.” Guidelines from the American College of Occupational and Environmental Medicine (Hegmann, 2007) state that therapeutic facet joint injections for acute, subacute, chronic low back pain or radicular pain syndrome are “not recommended”. An assessment by the Canadian Agency for Drugs and Technologies in Health (Zakaria et al, 2007) concluded: “According to the RCTs [randomized controlled trials] completed to date, FJIs [facet joint injections] with local anesthetics or steroids have not been proven to be superior to placebo for the treatment of chronic LBP [low back pain]. Steroid FJIs have not been proven to be superior to local anesthetic FJIs in the treatment of chronic neck pain secondary to a motor vehicle accident. The studies are limited. …” An assessment for BMJ Clinical Evidence (McIntosh and Hall, 2007) concluded that facet injections for chronic back pain are of “unknown effectiveness”. A Cochrane systematic evidence review found no clear differences between facet joint glucocorticoid and placebo injections (Staal et al, 2008). A review in UpToDate (Chou, 2009) stated: “Evidence is unavailable, unreliable, or contradictory regarding the effectiveness of glucocorticoid injections for other sites, including … facet joint injections …. We suggest not performing these procedures for chronic low back pain”.

Sacroiliac Joint Injections

Sacroiliac (SI) joint injections are performed by injecting a local anesthetic, with or without a steroid medication, into the SI joints. These injections may be given for diagnostic purposes to determine if the SI joint is the source of the low back pain or it may be performed to treat SI joint pain that has previously been detected/diagnosed. If the pain is relieved, the physician will know that the SI joint appears to be the source of pain. This may be followed up with therapeutic injections of anti-inflammatory (steroid) and/or local anesthetic medications to relieve pain for longer periods.

In a prospective, single-blinded, randomized controlled trial, Jee and colleagues (2014) compared the safety and short-term effects of ultrasound (US)-guided SIJ injections with fluoroscopy (FL)-guided SIJ injections in patients with non-inflammatory SIJ dysfunction (n = 120). All procedures were performed using an FL or US apparatus. Subjects were randomly assigned to either the FL or US group. Immediately after the SIJ injections, fluoroscopy was applied to verify the correct placement of the injected medication and intravascular injections. Treatment effects and functional improvement were compared at 2 and 12 weeks after the procedures. The verbal numeric pain scale and Oswestry Disability Index (ODI) improved at 2 and 12 weeks after the injections without statistical significances between groups. Of 55 US-guided injections, 48 (87.3%) were successful and 7 (12.7%) were missed. The FL-guided SIJ approach exhibited a greater accuracy (98.2%) than the US-guided approach. Vascularization around the SIJ was seen in 34 of 55 patients. Among the 34 patients, 7 had vascularization inside the joint, 23 had vascularization around the joint, and 4 had vascularization both inside and around the joint; 3 cases of intravascular injections occurred in the FL group. The authors concluded that the US-guided approach may facilitate the identification and avoidance of the critical vessels around or within the SIJ. Function and pain relief significantly improved in both groups without significant differences between groups. The US-guided approach was shown to be as effective as the FL-guided approach in treatment effects. However, diagnostic application in the SIJ may be limited because of the significantly lower accuracy rate (87.3%).

Radiofrequency Facet Denervation

Radiofrequency ablation (may also be referred to as RFA, percutaneous radiofrequency neuroablation, radiofrequency coagulation, radiofrequency denervation, radiofrequency lesioning, radiofrequency neuroablation, radiofrequency neurotomy or rhizotomy [articular rhizolysis]) involves the use of radiofrequency energy to denervate a nerve. One of the most commonly performed neuroablative procedures is facet denervation, which is the destruction or interruption of a facet joint nerve to relieve chronic pain in the cervical, thoracic or lumbar region of the spine.

Facet joints of the spine have joint capsules that are supplied by a branch of the posterior ramus of the spinal nerve. Percutaneous radiofrequency facet denervation, also known as radiofrequency facet joint rhizotomy or facet neurotomy, involves selective denervation using radiofrequency under fluoroscopic guidance. As a method of neurolysis, radiofrequency facet denervation has been shown to be a very safe procedure and can offer relief for many patients with mechanical LBP in whom organic pathology, most commonly a herniated lumbar disc, has been eliminated. According to the literature, it offers advantages over conventional neurolytic agents (e.g., phenol, alcohol, and hypertonic saline) because of its long lasting effects, the relative lack of discomfort, and its completely local action without any random diffusion of the neurolytic agent. Because there are no reliable clinical signs that confirm the diagnosis, successful relief of pain by injections of an anesthetic agent into the joints are necessary before proceeding with radiofrequency facet denervation. Results from many studies have shown that radiofrequency facet denervation results in significant (excellent or good) pain relief, reduced use of pain medication, increased return-to-work, and is associated with few complications. Success rate, however, depends on a careful selection of patients.

Laser Facet Denervation

Neuroablative techniques in pain management consist of several surgical and non-surgical methods to denervate a nerve. The goal of denervation is to “shut off” the pain signals that are sent to the brain from the joints and nerves. An additional objective is to reduce the likelihood of, or to delay, any recurrence by selectively destroying pain fibers without causing excessive sensory loss, motor dysfunction or other complications.

Laser ablation involves the use of laser to denervate a nerve. There is a lack of published evidence of laser facet denervation for lumbar facet pain.

Facet Chemodenervation / Chemical Facet Neurolysis

Chemical neurolysis (also referred to as chemical ablation, chemical denervation or chemodenervation) involves injection of neurolytic agents [eg, phenol, alcohol or hypertonic saline]) to denervate a nerve. The use of chemical facet injections such as alcohol, phenol and hypertonic saline has been proposed as an option for lumbar facet pain. However, there is a lack of published data to support the safety and effectiveness of this technique.

Spinal Fixation

Pedicle screw fixation systems consist of steel or titanium plates that are longitudinally inter-connected and anchored to adjacent vertebrae using bolts, hooks, or screws. Pedicle screw fixation in the spine is used to produce a rigid connection between 2 or more adjacent vertebrae in order to correct deformity and to stabilize the spine, thereby reducing pain and any neurological deficits. It is most often used in the lumbosacral spine from L1 though S1, and may also be used in the thoracic spine. Excision of tissues compressing the spinal cord (posterior decompression) is a common treatment for patients with herniated or subluxed vertebrae (spondylolisthesis), degenerative intervertebral discs, certain types of vertebral fractures, or spinal tumors. Spinal instability following decompression may be sufficiently severe to require stabilization by bony fusion (arthrodesis) of affected and adjacent vertebrae using implanted autologous bone grafts. Following placement of the graft, sufficient mechanical stability to allow its incorporation may be provided by combinations of various surgically implanted hooks, rods, or wires. However, severe instability may require surgical implantation of plates or rods anchored to vertebral pedicles using screws (pedicle screw fixation systems) in order to provide rigid 3-column fixation and minimize the risk of incomplete fusion (pseudoarthrosis or pseudarthrosis) or loss of alignment during fusion. The current medical literature suggests that rigid fixation of the lumbar spine with pedicle screws improves the chances of successful fusion as compared with patients with lumbar spine fusion not supplemented with internal fixation. Internal fusion and fixation are major operative procedures with significant risks and according to the available literature should be reserved for patients with spinal instability associated with neurological deficits, major spinal deformities, spinal fracture, spinal dislocation or complications of tumor. Spinal fusion and pedicle screw fixation has been shown not to be effective for the treatment of isolated chronic back pain, and surgery is not advocated to treat this diagnosis in the absence of instability or neurological deficits. In July 1998, the FDA re-classified into Class II the pedicle screw spinal systems intended to provide immobilization and stabilization of spinal segments in skeletally mature patients as an adjunct to fusion in the treatment of the following acute or chronic instabilities or deformities of the thoracic, lumbar, and sacral spine: degenerative spondylolisthesis with objective evidence of neurological impairment, fracture, dislocation, scoliosis, kyphosis, spinal tumor, and failed previous fusion (pseudarthrosis). Pedicle screw systems intended for any other uses are considered post-amendment Class III devices for which pre-market approval is required.

Intervertebral Body Fusion Devices (Spine Cages)

A spine cage, also known as an interbody cage, is a small hollow cylindrical device, usually made of titanium, with perforated walls. The device is placed in the disc space between 2 vertebrae to restore lost disc height resulting from a collapsed disc and to relieve pressure on nerve roots. Currently, there are 2 intervertebral body fusion devices approved by the FDA: the BAK Interbody Fusion System (Spine-Tech, Inc.), and the Ray Threaded Fusion Cage (Surgical Dynamics, a subsidiary of United States Surgical Corporation). The BAK (Bagley and Kuslich) Interbody Fusion System and the Ray Threaded Fusion Cage (TFC) are hollow cylinders made of titanium, which may be implanted by anterior or posterior approach. Unlike pedicle screws, both of these fusion devices are permanent implants, as the literature describes bone growing into and through the implant. The safety and effectiveness of these fusion devices have not been established in 3 or more levels to be fused, previous fusion attempt at the involved level(s), spondylolisthesis or retrolisthesis of Grade II or greater. Although the BAK has received FDA approval for implantation laparoscopically, studies performed for FDA approval demonstrated significantly greater incidence of complications from anterior spinal reconstructive surgery using a laparoscopic approach than using an open approach. Furthermore, patients with laparoscopically implanted BAK fusion devices were followed for only 6 months; thus, the long-term stability of laparoscopically implanted BAK cages is unknown. Thus, coverage of laparoscopic (endoscopic) implantation of the BAK should be denied as experimental and investigational. (See discussion of anterior endoscopic spinal reconstructive surgery above).

In a retrospective, database review, Pirkle and colleagues (2019) analyzed the rate of nonunion in patients treated with structural allograft and intervertebral cages in anterior cervical discectomy and fusion (ACDF). These investigators carried out a retrospective analysis of 6,130 patients registered in the PearlDiver national database through Humana Insurance from 2007 to 2016. All ACDF patients with anterior plating who were active in the database for at least 1 year were included in the study. Patients with a fracture history within 1 year of intervention, past arthrodesis of hand, foot, or ankle, or a planned posterior approach were excluded from the study. Patients were stratified by number of levels treated, tobacco use, and diabetic condition. Nonunion rates of structural allograft and intervertebral cage groups after 1 year were compared using Chi-squared analyses. A total of 4,063 patients were included in the allograft group, while 2,067 were included in the cage group. Overall nonunion rates were significantly higher in the cage group (5.32%) than in the allograft group (1.97%) (p < 0.01). When controlling for confounders, increased rates of nonunion were consistently observed in the cage group, achieving statistical significance in 25 of the 26 analyses. The authors concluded that the increased rate of nonunion associated with intervertebral cages may suggest the superiority of allograft over cages in ACDF. Level of evidence = III.

The authors noted that with any large database, there are weaknesses. The reliability of the reporting and coding was dependent upon multiple sources in an administrative data registry. These researchers were unable to obtain radiographic evidence of nonunion for individual patients and instead relied on the diagnosis codes for nonunion, an important assumption they have made in this study. As this was an observational database study, these investigators were also unable to determine the constitution of each cage placed, whether that be PEEK, titanium, mesh, or porous material. In this analysis, the authors stratified their initial population to account for the 3 most likely confounding variables for nonunion. It was entirely possible that other confounding variables exist and this may affect the analysis. Even with this large database, the nonunion patients whittled down to less than 11 patients in some sub-analyses. One of the limitations of PearlDiver was when patient population size was less than 11, the true number was not revealed because of the potential for patient identification. The authors encountered this in some of their sub-analyses and this limited their ability to analyze the data, particularly where they attempted to control for multiple confounders. These researchers stated that future studies utilizing other data sources with sufficient sample size may be of value in further investigation. However, the PearlDiver data have been widely utilized in peer-reviewed publication. To-date, this study is the largest comparative study examining the fusion rates of ACDF using cages and structural bone graft. The authors’ practice, like the majority of spine surgeons in North America, is to utilize structural bone graft in ACDF. These data suggested that allograft, when available, may be a superior option than the use of a cage in achieving arthrodesis in the cervical spine.

Key points in this study: Both structural allograft and intervertebral cage groups experienced high fusion rates. When comparing nonunion rates, these data suggested the superiority of allograft in ACDF. While the use of a cage and non-structural bone graft material remains an important surgical option, the use of allograft, when donor bone is available, may be preferable in achieving solid arthrodesis.

Vertebroplasty

Percutaneous polymethylmethacrylate vertebroplasty (PPV) is a therapeutic, interventional radiologic procedure, which consists of the injection of an acrylic bone cement (usually methyl methacrylate) into a cervical, thoracic or lumbar vertebral body lesion for the relief of pain and the strengthening of bone. The procedure is performed under fluoroscopic guidance with local anesthesia and moderate sedation. This procedure is being used for patients with lytic lesions due to bone metastases, aggressive hemangiomas, or multiple myeloma, and for patients who have medically intractable debilitating pain resulting from osteoporotic vertebral collapse.

Examples of PMMA include, but may not be limited to, Ascendx Cement, Cobalt HV, Cobalt V Radiopaque Vertebroplasty Bone Cement, Cohesion, Kyphx HV-R, Opacity+, Osteopal, Osteopal V, SPACE CpsXL, Spine-Fix Biomimetic Bone Cement, StabiliT ER, Vertecern and Vertefix Radiopaque Bone Cement. An alternative to traditional bone cement is Cortoss Bone Augmentation Material. Cortoss is an injectable, non-resorbable synthetic material that functions as a strengthening agent for injection into vertebral bodies with compression fractures.

Results from two uncontrolled prospective studies and several case series reports, including one with 187 patients, indicated that percutaneous vertebroplasty can produce significant pain relief and increase mobility in 70% to 80% of patients with osteolytic lesions in the vertebrae. In these reports, pain relief was apparent within 1 to 2 days after injection, and appeared to persist for at least several months up to several years. While experimental studies and preliminary clinical results suggest that percutaneous vertebroplasty can also strengthen the vertebral bodies and increase mobility, it remains to be proven whether this procedure can prevent additional fractures in the injected vertebrae. In addition, the duration of effect was not known; there were no long-term follow-up data on most of these patients, and these data may be difficult to obtain and interpret in patients with an underlying malignant process because disease progression may confound evaluation of the treatment effect. Complications were relatively rare, although some studies reported a high incidence of clinically insignificant leakage of bone cement into the paravertebral tissues. In a few cases, the leakage of polymer caused compression of spinal nerve roots or neuralgia. Several instances of pulmonary embolism were also reported.

The FDA (2004) notified healthcare professionals about complications related to the use of polymethylmethacrylate bone cement to treat osteoporotic compression fractures of the spine using vertebroplasty and kyphoplasty. Reported complications, such as soft tissue damage and nerve root pain and compression, are related specifically to the leakage of bone cement. Other reported complications include pulmonary embolism, respiratory and cardiac failure, and death.

Percutaneous vertebroplasty is an in-patient procedure because it may cause compression of adjacent structures and require emergency decompressive surgery. In addition, radiation therapy or concurrent surgical interventions, such as laminectomy, may also be required in patients with compression of the spinal cord due to ingrowth of a tumor. An assessment of percutaneous vertebroplasty by the National Institute for Clinical Excellence (NICE, 2003) concluded that “current evidence on the safety and efficacy of percutaneous vertebroplasty appears adequate”.

However, 2 subsequently published RCTs published in the New England Journal of Medicine have found no significant benefit with vertebroplasty. In the Investigational Vertebroplasty Safety and Efficacy Trial (INVEST), Kallmes et al (2009) reported that pain and disability outcomes at 1 month in a group of patients who underwent vertebroplasty were similar to those in a control group that underwent a sham procedure. In the other trial, Buchbinder et al (2009) measured pain, quality of life, and functional status at 1 week and at 1, 3, and 6 months after sham and active vertebroplasty and found there were no significant between-group differences at any time point. As in INVEST, patients in the 2 study groups had improvement in pain.

The Society for Interventional Radiology (SIR, 2009) had identified a number of issues in interpreting these studies, including potential biases in patient selection, the use of vertebroplasty in older (greater than 3 months) fractures, and a potentially inadequate amount of polymethylmethacrylate (PMMA) that was injected into the vertebrae. The SIR concluded: “We recognize the value of randomized controlled trials and evidence-based medicine. But based on the above-discussed weakness in the studies and the degree of discordance between the outcomes of these studies, prior studies and experience, we believe it is premature and possibly incorrect – to conclude that vertebroplasty is no better than a control sham procedure (trigger point, facet injection). We suggest waiting for the results of the VERTOSS 2 trial to be published and encourage larger clinical trials to address the weaknesses of the two New England Journal of Medicine articles”.

In a retrospective study, He and colleagues (2008) examined if a repeat percutaneous vertebroplasty (PV) is effective on pain-relief at the vertebral levels in patients who had previously undergone PV. Of the 334 procedures of PV performed in 242 patients with osteoporotic vertebral compression fractures from October 2000 to June 2006 in the authors’ institute, 15 vertebrae in 15 patients with unrelieved pain in 4 to 32 days after an initial PV were treated with a repeat vertebroplasty. The clinical outcomes were assessed by measurements of visual analog scale (VAS), and the imaging features were analyzed pre- and post-procedure. The mean volume of polymethylmethacrylate injected in each vertebra was 4.0 ml (range of 1.5 to 9 ml) in the repeat PV. During the first month of follow-up after repeat PV in this series, a mean VAS scores of the pain level was reduced from 8.6 (range of 7 to 10) pre-procedure to 1.67 points (range of 0 to 4) post-procedure, with a mean reduction of 6.93 points (range of 4 to 8). Complete and partial pain relief were reached in 11 (73%) and 4 patients (27%), respectively in a mean follow-up of 15 months. No serious complications related to the procedures occurred, however asymptomatic polymethylmethacrylate leakage around vertebrae was demonstrated on radiograph or computed tomography in 2 patients. The authors concluded that the outcomes of this series suggested that repeat PV is effective at the same vertebral levels in patients without pain-relief who underwent previous PV. Absent or inadequate filling of cement in the unstable fractured areas of the vertebral body may be responsible for the unrelieved pain after the initial PV.

An accompanying editorial by Kallmes (2008) of the afore-mentioned article stated that “[u]nfortunately, limitations in the current study likely preclude definitive answers, but still the series may help focus future studies”. The editorialist also noted that while the authors found insufficient or absent filling in 100% of the failed cases, they did not provide any information regarding the frequency in which they had insufficient or absent filling in the other 227 (successful) cases. Furthermore, Kallmes is still somewhat concerned about the safety of the repeat procedure.

Absolute contraindications to percutaneous vertebroplasty or kyphoplasty (balloon-assisted vertebroplasty) include, but may not be limited to, the following:

Allergy to bone cement or contrast media; or
Asymptomatic vertebral compression fractures; or
Individual is improving with medical therapy; or
Nonfractured vertebral levels; or
Ongoing local or systemic infection; or
Osteomyelitis of the target vertebra; or
Prophylactic treatment for osteoporosis to prevent future fractures; or
Retropulsed bone fragment resulting in myelopathy; or
Spinal canal compromise secondary to tumor resulting in myelopathy; or
Uncorrected coagulation disorders.

Relative contraindications to percutaneous vertebroplasty include, but may not be limited to, the following:

Asymptomatic retropulsion of a fracture fragment causing significant spinal compromise; or
Asymptomatic tumor extension into the epidural space; or
Radiculopathy in excess of vertebral pain, caused by a compressive syndrome unrelated to vertebral collapse.

Clark et al (2016) hypothesized that vertebroplasty would provide effective analgesia for patients with poorly controlled pain and osteoporotic spinal fractures of less than 6 weeks’ duration. The effectiveness of vertebroplasty, using an adequate vertebral fill technique, in fractures of less than 6 weeks’ duration has not been specifically assessed by previously published masked trials. This was a multi-center, randomized, double-blind, placebo-controlled trial of vertebroplasty in 4 hospitals in Sydney, Australia. These researchers recruited patients with 1 or 2 osteoporotic vertebral fractures of less than 6 weeks’ duration and Numeric Rated Scale (NRS) back pain greater than or equal to 7 out of 10. They used an automated telephone randomization service provided by the National Health and Medical Research Council to assign patients (1:1; stratified according to age, degree of vertebral compression, trauma, corticosteroid use, and hospital) to either vertebroplasty or placebo, immediately before the procedure. Patients received conscious sedation. Vertebroplasty was carried out with the adequate vertebral fill technique and the placebo procedure with simulated vertebroplasty. Follow-up was for 6 months. Outcome assessors and patients were masked to treatment allocation. The primary outcome was the proportion of patients with NRS pain below 4 out of 10 at 14 days post-intervention in the intention-to-treat population. Between November 4, 2011, and December 5, 2014, a total of 120 patients were enrolled; 61 patients were randomly assigned to vertebroplasty and 59 to placebo. A total of 24 (44 %) patients in the vertebroplasty group and 12 (21 %) in the control group had an NRS pain score below 4 out of 10 at 14 days (between-group difference 23 percentage points, 95 % CI: 6 to 39; p = 0·011); 3 patients in each group died from causes judged unrelated to the procedure. There were two serious adverse events (AEs) in each group, related to the procedure (vertebroplasty group) and the fracture (control group). The authors concluded that this trial showed effectiveness for vertebroplasty in reducing pain from osteoporotic spinal fractures of less than 6 weeks when compared with a true placebo control. Subgroup analysis suggested that most benefit from vertebroplasty was in the thoracolumbar spinal segment and further research is needed to evaluate this finding.

The authors stated that this study had several drawbacks. First, 8 patients (6 vertebroplasty and 2 placebo) did not have day-14 outcome measures because of revoking consent, delirium, or not being contactable. If all were included in the analysis and presumed to be treatment failures, there would be a minor effect on primary outcome (between-group difference 19 percentage points, 95 % CI: 3 to 35; p = 0.023). Second, 20 patients (11 vertebroplasty and 9 placebo) were unable to attend the clinic at day-14 and were interviewed by telephone. The NRS pain question did not change so this should not have affected the primary outcome. Third, 85 % of the procedures were performed in 1 center. Centers with high procedure rates could have superior outcomes possibly affecting the generalizability of these findings. This proportion was not greatly dissimilar to one masked trial where 68 % (53 of 78) of procedures were done in 1 centre and 87 % (68 of 78) in 2 centers; but was quite different to the other masked trial. in this regard, recruitment in 3 of the 4 centers proved difficult, as for previous placebo trials, and they failed to meet their enrolment targets. In an editorial, Hijji et al (2017) stated that the clinical value of study by Clark et al (2016) may be limited. The previously performed randomized controlled trials by Kallmes et al (2009) and Buchbinder et al (2009) identified no differences in outcomes following control and vertebroplasty treatments for osteoporotic vertebral fractures; however, the study populations consisted of patients presenting early and late following the onset of their symptomology. One of the primary reasons for performing this study was to identify whether early intervention with vertebroplasty would improve patient outcomes compared to conservative management. However, to strengthen the conclusions, especially in the setting of conflicting findings to these previous studies, the present study should have also compared early intervention to late intervention. Both previous studies were able to perform subgroup analyses with patients undergoing early intervention, maintaining the result that no benefit was achieved with vertebroplasty compared to placebo treatment. However, the patient population in the current trial only included those receiving early intervention; therefore, not allowing for this separate analysis. As such, it was difficult to conclude that it was the early intervention itself that caused the conflicting results, especially in combination with the methodological flaws mentioned previously. The authors also attempted to supplement their clinical findings with radiographic data; however, their measurements relied simply on vertebral height of the affected vertebral bodies. This also had limited utility, as the polymethylmethacrylate (PMMA) used in the vertebroplasty could substantially impact the radiographic interpretation due to its radiopaque qualities. Hijji et al (2017) noted that the study by Clark et al (2016) did improve on a few of the drawbacks exhibited in previous RCTs examining vertebroplasty; however, the flaws of this study significantly limited its ability to provide any substantial conclusions regarding the effectiveness of vertebroplasty for osteoporotic vertebral fractures. The previously performed double-blind, RCTs appeared to be of superior methodological quality, bringing into question the conflicting findings of the study by Clark et al (2016). The editorialists stated that further investigations with larger sample sizes and improved analytic and recruitment methods are needed to overcome many of the drawbacks of this study.

In a prospective, randomized , single-center study, Yang et al (2016) examined if percutaneous vertebroplasty (PVP) would offer extra benefits to aged patients with acute osteoporotic vertebral compression fractures (OVCFs) over conservative therapy (CV). Patients aged at 70 years or above with acute OVCF and severe pain from minor or mild trauma were assigned randomly to PVP and CV groups. The primary outcome was pain relief as measured by VAS score in 1-year follow-up period. The second outcome was quality of life assessed with ODI and Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO). Patient satisfaction surveys were also recorded. A total of 135 patients were enrolled, and 107 (56 in PVP group; 51 in CV group) completed 1-year follow-up. In PVP group, the vertebroplasty procedure was performed at a mean of 8.4 ± 4.6 days (range of 2 to 21 days) after onset. Vertebroplasty resulted in much greater pain relief than did conservative treatment at postoperative day 1 (p < 0.0001). At every time-point of follow-up, pain relief and QOL were significantly improved in PVP group than in CV group at 1 week, 1 month, 3 months, 6 months, and 1 year (all p < 0.0001). The final follow-up surveys indicated that patients in PVP group were significantly more satisfied with given treatment (p < 0.0001). Furthermore, lower rate of complications was observed in PVP group (p < 0.0001). The authors concluded that in aged patients with acute OVCF and severe pain, early vertebroplasty yielded faster, better pain relief and improved functional outcomes, which were maintained for 1 year. Furthermore, it showed fewer complications than conservative treatment. Level of Evidence = II.

The authors stated that the major drawback of this trial was its single-center design with relatively small population (56 in the PVP group) and short-term follow-up (1 year). Second, the findings were not generalizable because of the small sample from a single institution. These researchers intended to continue their study with satisfactory randomization to involve multi-center researchers and determine the long-term outcomes of the procedure. Third, treatment could not be masked. Different from the blinded randomized controlled study, knowledge of the assignment may have affected patient responses to questions or researcher assessments. However, this limitation is difficult to overcome in this type of study.

In a commentary on the study by Yang et al (2016), Kaito (2016) stated that even after 2 RCTs in which patients with back pain and vertebral fracture underwent either VP or sham intervention showed no significant differences in outcomes between these procedures until 6 postoperative months in 2009, the effectiveness of VP is still controversial. These trials recently reported no significant difference between outcomes of VP and the sham intervention at 1 and 2 post-operative years. Kaito (2016) noted that although the findings of the study by Yang et al (2016) were not generalizable because of the small sample from a single institution, the authors appropriately acknowledged limitations of the design, which prohibited the drawing of a strong causal inference, and the small sample, which limited their ability to control for confounding differences. Kaito stated that Yang et al addressed an interesting and highly controversial topic. VP is likely to be unnecessary for all patients with painful osteoporotic vertebral fractures; however, the patients who will truly benefit from surgery need to be better identified.

Buchbinder et al (2018) noted that percutaneous vertebroplasty remains widely used to treat osteoporotic vertebral fractures although their 2015 Cochrane review did not support its role in routine practice. These investigators updated the available evidence of the benefits and harms of vertebroplasty for treatment of osteoporotic vertebral fractures. They updated the search of CENTRAL, Medline, and Embase and trial registries to November 15, 2017. These investigators included RCTs and quasi-RCTs of adults with painful osteoporotic vertebral fractures, comparing vertebroplasty with placebo (sham), usual care, or another intervention. As it is least prone to bias, vertebroplasty compared with placebo was the primary comparison. Major outcomes were mean overall pain, disability, disease-specific and overall health-related quality of life (HR-QOL), patient-reported treatment success, new symptomatic vertebral fractures and number of other serious adverse events (AEs). They used standard methodologic procedures expected by Cochrane. A total of 21 trials were included: 5 compared vertebroplasty with placebo (541 randomised participants), 8 with usual care (1,136 randomised participants), 7 with kyphoplasty (968 randomised participants) and 1 compared vertebroplasty with facet joint glucocorticoid injection (217 randomised participants). Trial size varied from 46 to 404 participants, most participants were female, mean age ranged between 62.6 and 81 years, and mean symptom duration varied from 1 week to more than 6 months. A total of 3 placebo-controlled trials were at low-risk of bias and 2 were possibly susceptible to performance and detection bias. Other trials were at risk of bias for several criteria, most notably due to lack of participant and personnel blinding. Compared with placebo, high- to moderate-quality evidence from 5 trials (1 with incomplete data reported) indicated that vertebroplasty provided no clinically important benefits with respect to pain, disability, disease-specific, or overall QOL, or treatment success at 1 month. Evidence for QOL and treatment success was down-graded due to possible imprecision. Evidence was not down-graded for potential publication bias as only 1 placebo-controlled trial remains unreported. Mean pain (on a scale 0 to 10, higher scores indicate more pain) was 5 points with placebo and 0.6 points better (0.2 better to 1 better) with vertebroplasty, an absolute pain reduction of 6 % (2 % better to 10 % better, minimal clinical important difference is 15 %) and relative reduction of 9 % (3 % better to 14 % better) (5 trials, 535 participants). Mean disability measured by the Roland-Morris Disability Questionnaire (scale range 0 to 23, higher scores indicate worse disability) was 14.2 points in the placebo group and 1.7 points better (0.3 better to 3.1 better) in the vertebroplasty group, absolute improvement 7 % (1 % to 14 % better), relative improvement 10 % better (3 % to 18 % better) (3 trials, 296 participants). Disease-specific QOL measured by the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO) (scale 0 to 100, higher scores indicating worse QOL) was 62 points in the placebo group and 2.75 points (3.53 worse to 9.02 better) in the vertebroplasty group, absolute change: 3 % better (4 % worse to 9 % better), relative change: 5 % better (6 % worse to 15 % better (2 trials, 175 participants). Overall QOL (European Quality of Life (EQ5D), 0 = death to 1 = perfect health, higher scores indicate greater QOL) was 0.38 points in the placebo group and 0.05 points better (0.01 better to 0.09 better) in the vertebroplasty group, absolute improvement: 5 % (1 % to 9 % better), relative improvement: 18 % (4 % to 32 % better) (3 trials, 285 participants). In 1 trial (78 participants), 9/40 (or 225 per 1,000) people perceived that treatment was successful in the placebo group compared with 12/38 (or 315 per 1,000; 95 % CI: 150 to 664) in the vertebroplasty group, RR 1.40 (95 % CI: 0.67 to 2.95), absolute difference: 9 % more reported success (11 % fewer to 29 % more); relative change: 40 % more reported success (33 % fewer to 195 % more). Moderate-quality evidence (low number of events) from 7 trials (4 placebo, 3 usual care, 1,020 participants), up to 24 months follow-up, indicated they were uncertain whether vertebroplasty increased the risk of new symptomatic vertebral fractures (70/509 (or 130 per 1,000; range of 60 to 247) observed in the vertebroplasty group compared with 59/511 (120 per 1,000) in the control group; RR 1.08 (95 % CI: 0.62 to 1.87)). Similarly, moderate-quality evidence (low number of events) from 5 trials (3 placebo, 2 usual care, 821 participants), indicated uncertainty around the risk of other serious AEs (18/408 or 76 per 1,000, range 6 to 156) in the vertebroplasty group compared with 26/413 (or 106 per 1,000) in the control group; RR 0.64 (95 % CI: 0.36 to 1.12). Notably, serious AEs reported with vertebroplasty included osteomyelitis, cord compression, thecal sac injury, and respiratory failure. Subgroup analyses indicated that the effects did not differ according to duration of pain 6 weeks or less versus more than 6 weeks. Including data from the 8 trials that compared vertebroplasty with usual care in a sensitivity analyses altered the primary results, with all combined analyses displaying considerable heterogeneity. The authors concluded that based upon high- to moderate-quality evidence, our updated review does not support a role for vertebroplasty for treating acute or subacute osteoporotic vertebral fractures in routine practice. These researchers found no demonstrable clinically important benefits compared with placebo (sham procedure) and subgroup analyses indicated that the results did not differ according to duration of pain of 6 weeks or less versus more than 6 weeks. Sensitivity analyses confirmed that open trials comparing vertebroplasty with usual care are likely to have over-estimated any benefit of vertebroplasty. Correcting for these biases would likely drive any benefits observed with vertebroplasty towards the null, in keeping with findings from the placebo-controlled trials. Numerous serious AEs have been observed following vertebroplasty. However due to the small number of events, the authors could not be certain regarding whether or not vertebroplasty results in a clinically important increased risk of new symptomatic vertebral fractures and/or other serious AEs. These researchers stated that patients should be informed about both the high- to moderate-quality evidence that showed no important benefit of vertebroplasty and its potential for harm.

In a commentary on the updated Cochrane review by Buchbinder et al (2018), Bozzo and Bhandari (2018) stated that it is rare to have sham surgery-controlled trials in orthopedics, and even less common to have 5 such trials contributing to a high GRADE of evidence supporting clinical decision making. Since the pooled results of vertebroplasty did not provide patients with a clinically important improvement in pain or function in this Cochrane review, it does not support the routine use of vertebroplasty for osteoporotic vertebral fractures. The main findings of this meta-analysis were consistent with the one previously conducted by the same authors from 3 years ago and replicated in other recent meta-analyses of randomized controlled trials on this topic (Robinson and Olerud, 2012; Shi et al, 2012; and Stevenson et al, 2014). However, it is possible that patients with osteoporotic vertebral compression fractures experiencing pain for longer than 6 months who have MRI evidence of bone edema may benefit from vertebroplasty, although this was not assessed in this review. Bozzo and Bhandari (2018) stated that future trials could examine if this particular subgroup of patients may benefit from vertebroplasty and additional large observational studies might seek to replicate the suggestion that vertebroplasty may be associated with improved survival after vertebral fracture. They noted that while this commonly performed procedure still has its adherents], the best evidence as summarized by the updated Cochrane review suggests that vertebroplasty is ineffective in the general osteoporotic vertebral fracture patient population. Supporters of vertebroplasty should design appropriately controlled randomized clinical trials focusing on the subgroups they believe may experience a benefit from this invasive intervention. Until such subgroups are identified, there appeared to be little high-quality evidence in support of vertebroplasty for osteoporotic vertebral compression fractures. In the context of shared decision-making with patients, physicians should present this recent high-quality evidence that showed no clinical benefit from vertebroplasty.

In a systematic review and meta-analysis, Lin et al (2021) examined the safety and effectiveness of new implant-assisted vertebral augmentation (VA) techniques in recent years. The PubMed, Embase, Ovid, and SpringerLink databases were searched for RCTs on VA in the treatment of osteoporotic vertebral compression fractures (OVCF). In this study, patients in the experimental group were treated with PVP using the new implant-assisted VA technique, while patients in the control group were treated with PKP. Bias assessment was conducted using the tool integrated with the Revman 5.4 software, and meta-analysis was performed to compare the mid-term post-operative pain relief, functional status, QOL, and cement extravasation between the 2 groups (each presented with a forest plot). A total of 8 articles were finally included in the selection, involving a total of 1,027 patients. PVP surgery using the new implant-assisted VA technique was superior to PKP surgery in relieving post-operative pain (MD = -3.77, 95 % CI: -5.63 to -1.92, p < 0.0001) and improving the post-operative ODI score (MD =-1.59, 95 % CI: -3.01 to -0.16, p = 0.03). However, it was not significantly different from PKP surgery in improving post-operative QOL (MD =-0.27, 95 % CI: -3.55 to 3.01, p = 0.87), and the cement extravasation rate was significantly lower than that of PKP surgery [OR = 0.38, 95 % CI: 0.19 to 0.74, p = 0.004]. The authors concluded that the new implant-assisted VA technique could significantly relieve pain, reduce clinical symptoms, improve post-operative QOL, and significantly reduced the problem of cement extravasation. Moreover, these researchers stated that this new technology is still evolving, and more high-quality RCTs on this topic are needed to provide stronger evidence.

Ganguli et al (2021) operationalized 41 claims-based, low-value care definitions described in prior research and in the Milliman MedInsight Health Waste Calculator, a stand-alone, proprietary software program that identifies potentially inefficient services based on recommendations from the Choosing Wisely campaign and professional medical societies. The authors provided the following information:

Low-Value Service Measure Descriptions – Do not perform vertebroplasty for osteoporotic vertebral fractures

In a meta-analysis, Zhu et al (2022) examined clinical and radiographic outcomes of kyphoplasty (KP) compared with vertebroplasty (VP). These investigators searched articles published based on the electronic databases, including PubMed, Embase, and Cochrane Library. Publications of studies comparing KP with VP in the treatment of OVCFs were collected. After rigorous and thorough review of study quality, these researchers extracted the data on the basis of eligible trials, which analyzed the summary hazard ratios (HRs) of the end-points of interest. The inclusion criteria involved a total of 6 studies, entailing 644 patients, 330 who received VP and 284 who received KP. There was no significant difference in either group in terms of VAS scores (MD = 0.17; 95 % CI: -0.39 to 0.73; p = 0.56), risk of cement leakage (OR = 1.31; 95 % CI: 0.62 to 2.74; p = 0.47), or ODI scores (MD = 0.51; 95 % CI: -1.87 to 2.88; p = 0.68). Nevertheless, the injected cement volume (MD = -0.52; 95 % CI: -0.88 to -0.15; p = 0.005) in the VP group was linked to a markedly lower statistically significant trend compared with the KP group. The authors concluded that this meta-analysis evaluated acceptable effectiveness levels across the involved trials. VP injected cement volume had several advantages in this meta-analysis; however, no significant differences were observed in terms of VAS scores, ODI scores, or cement leakage when KP was compared to VP therapy. These researchers stated that given the combined results of this study, the optimal treatment for patients with OVCFs should be determined by further high-quality multi-center RCTs with longer follow-up and larger sample sizes.

Qiu et al (2023) examined the effect of vertebral augmentation (VA) in the treatment of single-level OVCFs on new vertebral fractures. Electronic databases PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched from database inception to September 5, 2022. Eligible studies had to use VA as an intervention and conservative treatment as a control group. Studies had to explicitly report whether new vertebral fractures occurred during follow-up. Data were extracted by multiple investigators. Data were pooled using random or fixed effects models depending on the degree of heterogeneity. Of the 682 articles screened, 7 met the inclusion criteria and were included in the analysis, giving a total of 1,240 patients. Meta-analysis showed that VA (OR = 2.10, 95 % CI: 1.35 to 3.28, p = 0.001) increased the risk of new post-operative vertebral fractures compared with conservative treatment. Subgroup analyses showed that the risk was greater in the group with a follow-up time greater than 1 year (OR = 2.57, 95 % CI: 1.06 to 6.26, p = 0.001). Compared with conservative treatment, VA (OR = 2.17, 95 % CI: 1.23 to 3.82, p = 0.007) increased the risk of post-operative adjacent vertebral fracture. The authors concluded that VA was associated with an increased risk of new vertebral fractures and adjacent vertebral fractures following single-level OVCFs. With longer follow-ups, new vertebral fractures may be more significant. These investigators stated that clinical surgeons should pay attention to long-term post-operative complications and choose treatment carefully.

Kyphoplasty

Kyphoplasty (also known as balloon-assisted vertebroplasty) is a minimally-invasive orthopedic procedure, which has been developed to restore bone height lost due to painful osteoporotic compression fractures. It is a modification of the vertebroplasty procedure, and involves the insertion of 1 or 2 balloon devices into the fractured vertebral body. Once inserted, the surgeon inflates the balloon(s) to create a cavity and to compact the deteriorated bone with the intent to restore vertebral height. The balloon(s) are then removed and the newly created cavity is filled with the surgeon’s choice of bone filler material, creating an internal cast for the fractured area.

The Kiva VCF Treatment System is an implantable device which has been proposed for use with a vertebroplasty or kyphoplasty procedure for reduction and treatment of spinal fractures. PMMA bone cement is used to fill the implant once it is placed.

An assessment of balloon kyphoplasty by the National Institute for Health and Clinical Excellence (NICE, 2006) concluded that “[c]urrent evidence on the safety and efficacy of balloon kyphoplasty for vertebral compression fractures appears adequate to support the use of this procedure provided that normal arrangements are in place for consent, audit and clinical governance”. The NICE assessment reviewed 3 non-randomized studies, 2 of which compared balloon kyphoplasty with conventional medical care (physical and analgesic therapy) and 1 which compared the procedure with vertebroplasty. All 3 studies found that patients who had undergone balloon kyphoplasty had improved pain scores compared with the control group at a maximum follow-up of 24 months. The assessment noted that the specialist advisors to NICE expressed uncertainties about whether the improvements following balloon kyphoplasty (reduced pain and height restoration) are maintained in the long term. In clinical studies, the most common complication following balloon kyphoplasty was cement leakage, occurring in up to 11% of patients. Other potential complications of kyphoplasty include infection, allergy, and spinal cord or nerve root injury caused by incorrect needle placement.

Based on the results of an assessment, the Ontario Ministry of Health and Long Term Care (2004) reached the following conclusions about balloon kyphoplasty: “There are currently two methods of cement injection for the treatment of osteoporotic VCFs. These are vertebroplasty and balloon kyphoplasty. Although no RCT has been conducted to compare the two techniques, the existing evidence shows that balloon kyphoplasty is a reasonable alternative to vertebroplasty, given the lower reported peri-operative and long-term complications of balloon kyphoplasty”.

Wardlaw et al (2009) reported positive results with kyphoplasty compared with non-surgical care in a non-blinded, multi-center RCT. The investigators randomly assigned 300 adults with 1 to 3 acute vertebral fractures to kyphoplasty (n = 149) or non-surgical care (n = 151). At 1 month, mean SF-36 Physical Component Score (PCS) improved by 7.2 points (95% confidence interval [CI]: 5.7 to 8.8) in the kyphoplasty group, and by 2.0 points (95% CI: 0.4 to 3.6) in the non-surgical group, a difference between groups that was statistically significant (p < 0.0001). The investigators reported that the frequency of adverse events did not differ between groups. There were 2 serious adverse events related to kyphoplasty (hematoma and urinary tract infection); other serious adverse events (such as myocardial infarction and pulmonary embolism) did not occur peri-operatively and were not related to procedure. Limitations of this study include the lack of blinding, and comparison to conservative treatment rather than a sham procedure.

The California Technology Assessment Forum (Karliner, 2009) concluded that balloon kyphoplasty meets CTAF criteria for safety, effectiveness and improvement in health outcomes for the treatment of recent (less than 3 month old) osteoporotic vertebral compression fractures confirmed by MRI.

Sacroplasty

Sacroplasty is a variation of the vertebroplasty technique, and involves the injection of polymethylmethacrylate cement into sacral insufficiency fractures for stabilization. Under fluoroscopic guidance, PMMA is injected into the sacrum at the fracture site, in an attempt to stabilize the fracture. Sacral insufficiency fractures (SIFs) can cause LBP in osteoporotic patients. Symptomatic improvement may require up to 12 months. Treatment includes limited weight-bearing and bed rest, oral analgesics, and sacral corsets. Significant mortality and morbidity are associated with pelvic insufficiency fractures. Percutaneous sacroplasty is being developed as an alternative treatment for SIF patients.

Frey et al (2007) reported on a prospective observational cohort study of the safety and efficacy of sacroplasty in consecutive osteoporotic patients with SIFs. Each procedure was performed under intravenous conscious sedation using fluoroscopy. Two bone trochars were inserted between the sacral foramen and sacroiliac joint through which 2 to 3 ml of polymethylmethacrylate was injected. A total of 37 patients, 27 females, were treated. Mean age was 76.6 years, and mean symptom duration was 34.4 days. All patients were available at each follow-up interval except 1 patient who died due to unrelated pulmonary disease before the 4-week follow-up. The investigators reported that mean VAS score at baseline was 7.7 and 3.2 within 30 mins, and 2.1 at 2, 1.7 at 4, 1.3 at 12, 1.0 at 24, and 0.7 at 52 weeks post-procedure. The investigators found that improvement at each interval and overall was statistically significant using the Wilcoxon Rank Sum Test. One case of transient S1 radiculitis was encountered. The investigators concluded that sacroplasty appears to be a safe and effective treatment for painful SIF. Limitations of this study include its small size, limited duration of follow-up, and lack of control group.

Vesselplasty

Vesselplasty (Vessel-X, A-Spine Holding Group Corp., Taipei, Taiwan) is an image-guided procedure that attempts to solve the problem of cement leakage out of the vertebral body, which can happen during both vertebroplasty and kyphoplasty. Cement leakage, a common problem with vertebroplasty particularly in lytic lesions (Mathis and Wong, 2003), has been reported in up to 30% to 70% of cases. Most occurrences, however, are asymptomatic (Cortet et al, 1997). Vesselplasty uses a porous polyethylene terephthalate balloon to create both a cavity and contain the cement, thereby, allowing only a small amount of cement to permeate into the vertebral body.

Flors et al (2009) evaluated the use of vesselplasty to treat symptomatic vertebral compression fractures (VCFs) in 29 patients. All patients had been undergoing medical therapy for 1 or more painful VCFs. Pain, mobility, and analgesic use scores were obtained, and restoration of vertebral body height was evaluated. A 2-tailed paired Student’s t test was used to compare differences in the mean scores for levels of pain, mobility, and analgesic use before and after the procedure and to evaluate changes in vertebral body height. Seven of the 29 patients had fractures in more than 1 level, for a total of 37 procedures. The cause of the vertebral collapse was osteoporosis in 27 (73%), high-impact trauma in 5 (13.5%), myeloma in 3 (8%), and metastatic fracture in 2 (5.4%). The average pain score before treatment was 8.72 +/- 1.25 (SD), whereas the average pain score after treatment was 3.38 +/- 2.35. The average mobility score before treatment was 2.31 +/- 1.94, whereas the average mobility score after treatment was 0.59 +/- 1.05 (p < 0.001). The average analgesic use score before treatment was 3.07 +/- 1.46, whereas it was 1.86 +/- 1.90 after treatment (p < 0.001). There was no evidence of clinical complications. The authors concluded that vesselplasty offers statistically significant benefits in improvements of pain, mobility, and the need for analgesia in patients with symptomatic VCFs, thus providing a safe alternative in the treatment of these fractures.

While vesselplasty appears to be a promising new technique for VCFs, there is insufficient evidence of its safety and effectiveness. Prospective, randomized, controlled studies with a larger number of patients and long-term follow-up are needed.

Epiduroscopy

Epiduroscopy involves insertion of a fiberoptic camera through the sacral hiatus into the lower epidural space, which is then guided upwards towards the lower lumbar discs and nerve roots. Epidural adhesions can be released and anesthetic and steroid injected around nerve roots. In September 1996, the epiduroscope (myeloscope) was cleared by the FDA for visualization of the epidural space. It has been used in the outpatient setting for the diagnosis and treatment of intractable LBP. Insertion of this miniature fiberoptic scope into the epidural space allows direct visualization of scarring and placement of a catheter through which fluid is injected under pressure to break down scar tissue and lyse adhesions. Although a number of pain treatment centers advertise the availability of this technique and claim it to be successful, there is insufficient scientific evidence in the peer-reviewed medical literature to support the clinical utility of this technique for diagnosis or therapy in patients with spinal pain syndromes, including those with failed back surgery syndromes. Moreover, currently available non-invasive technologies allow adequate visualization of the epidural space to confirm pathology contained therein. An assessment of epiduroscopy for the Australian Safety and Efficacy Register of New Interventional Procedures (ASERNIP-S, 2003) concluded that “[t]here is little high-quality evidence available on the safety and efficacy of epiduroscopically guided surgery/drug delivery… More studies are needed to compare the safety and efficacy of epiduroscopy relative to other procedures”. An assessment by the National Institute for Clinical Excellence (NICE, 2004) concluded that “current evidence on the safety and efficacy of endoscopic epidural procedures does not appear adequate for these procedures to be used without special arrangements for consent and for audit or research.” The NICE assessment found that “The studies identified were small and uncontrolled. Some measures used in these studies to assess outcomes, such as scores of pain and function, were of unknown validity”.

Epidural Lysis of Adhesions

Epidural lysis of adhesions is a pain management procedure that has been proposed as a method to relieve chronic back pain. This procedure may also be known as adhesiolysis, endoscopic adhesiolysis, epidurolysis, percutaneous adhesiolysis or percutaneous epidural neuroplasty. It differs from epidural injections as it attempts to treat the neural (nerve) adhesions that cause the pain. Epidural lysis of adhesions can be performed by use of a fiberoptic endoscope (epiduroscopy), percutaneously with the use of a catheter (flexible tube) or with the more specialized Racz catheter.

In epiduroscopy, normal saline is injected into the sacral canal to distend and decompress the epidural space; purportedly the fiberoptic endoscope can then directly disrupt the fibrosis, scar tissue or adhesions. This procedure is generally an outpatient procedure utilizing local anesthesia and light sedation.

In the percutaneous procedure utilizing the Racz catheter, the specialized epidural catheter is inserted under fluoroscopy via the sacral canal. The injection of dye (an epidurogram) may indicate the area of adhesions and provide a way to perform lesion-specific lysis utilizing the flexible wire embedded catheter. Local anesthetic, corticosteroid and hypertonic sodium chloride solution injections via the catheter are performed daily for three days. During this time the catheter is left in place and the individual is generally hospitalized.

A similar version of the procedure involves a single use catheter (instead of the Racz catheter) which is removed after the lysis is completed. The procedure may be repeated at a later date, but would require a new catheter placement.

The Racz catheter is a small caliber, flexible catheter that is introduced into the sacral hiatus and into the lumbro-sacral epidural space. The Racz catheter is used to release adhesions deliver steroids and anesthetics into the epidural space. There is no evidence from adequate well-designed RCTs in the peer-reviewed medical literature supporting the safety and effectiveness of manipulation of an indwelling epidural Racz catheter or epidural injections of hypertonic saline or hyaluronidase to relieve back pain in patients with epidural adhesions, adhesive arachnoiditis, or failed back syndrome from multiple previous surgeries for herniated lumbar disk. The Racz epidural catheter was cleared by the FDA based on a 510(k) pre-market notification (PMN) due to FDA’s judgment that the device was “substantially equivalent” to devices that were marketed prior to the 1976 Medical Device Amendments to the Food, Drug and Cosmetic Act; thus, the manufacturer was not required to provide the evidence of effectiveness that is necessary to support a pre-market approval (PMA) application. Most of the reported studies of the Racz catheter are retrospective (Racz and Holubec, 1989; Manchikanti et al, 2001; Manchikanti et al, 1999) or lacking a control group (Racz et al, 1999). Manchikanti, founder and president of the American Society of Interventional Pain Physicians (ASIPP), is a leading advocate of the use of the Racz catheter (Manchikanti et al, 1999; Manchikanti and Bakhit, 2000; Manchikanti and Singh, 2002). He is lead author of ASIPP guidelines which incorporate the Racz catheter into the management of chronic spinal pain (Manchikanti et al, 2003). Manchikanti et al (2001, 2004) has reported the results of 2 controlled clinical studies of the Racz catheter in the ASIPP’s official journal Pain Physician. One of these studies involved 45 patients with chronic LBP, 30 of whom received Racz catheter treatment, and a control group of 15 patients who did not receive Racz catheter treatment. The study was unblinded and utilized a biased control group, as control group subjects were patients who refused Racz catheter treatment, either because coverage was denied by their insurer or for other reasons (Manchikanti et al, 2001). In another study, subjects with chronic LBP were randomized to a sham control group or 2 treatment groups (n = 25 in each group). Nineteen of 25 subjects in the control group were unblinded or lost to follow-up before completion of the 12-month study (Manchikanti et al, 2004). Both of these controlled clinical studies involve small groups of patients and are from the same group of investigators from a single private practice, raising questions about the generalizability of the findings (Manchikanti et al, 2001: Manchikanti et al, 2004). The small sample sizes of these studies do not allow adequate evaluation of potential adverse outcomes that may occur with the procedure (Fibuch, 1999). A Joint Health Technology Assessment of the German Medical Association and the German National Association of Statutory Health Insurance Physicians (KBV, 2003) concluded that, “due to insufficient evaluation and lack of empirical data, at present there is no convincing evidence for the efficacy or effectiveness of the Racz treatment procedure”.

The National Institute for Clinical Excellence (NICE, 2004) assessed mobilization and division of epidural adhesions, and concluded that “[c]urrent evidence on the safety and efficacy of endoscopic division of epidural adhesions does not appear adequate for this procedure to be used without special arrangements for consent and for audit or research”. The assessment noted that studies of epidural lysis of adhesions are “small and uncontrolled”. In addition, NICE noted that “[s]ome measures used in the studies to assess outcomes, such as scores of pain and function, were of unknown validity”. NICE stated that the main safety concerns are infection, bleeding, neurological damage, epidural hematoma, and damage to the nerve roots or cauda equina.

Veihelmann et al (2006) examined if epidural neuroplasty is superior to conservative treatment with physiotherapy in treating patients with chronic sciatica with or without LBP. A total of 99 patients with chronic LBP were enrolled in this study and randomly assigned into either a group with physiotherapy (n = 52) or a second group undergoing epidural neuroplasty (n = 47). Patients were assessed before and 3, 6, and 12 months after treatment by a blinded investigator. After 3 months, the VAS score for back and leg pain was significantly reduced in the epidural neuroplasty group, and the need for pain medication was reduced in both groups. Furthermore, the VAS for back and leg pain as well as the Oswestry disability score were significantly reduced until 12 months after the procedure in contrast to the group that received conservative treatment. The authors concluded that epidural neuroplasty results in significant alleviation of pain and functional disability in patients with chronic LBP and sciatica based on disc protrusion/prolapse or failed back surgery on a short-term basis as well as at 12 months of follow-up. Moreover, these investigators stated that further prospective randomized double-blinded studies are needed to prove the effectiveness of epidural neuroplasty in comparison to placebo and in comparison to open discectomy procedures.

Microsurgical Anterior Foraminotomy

Microsurgical anterior foraminotomy has been developed to improve the treatment of intractable cervical radiculopathy. This new technique provides direct anatomical decompression of compressed nerve roots by removing the compressive spondylotic spur or disc fragments through the holes of unilateral anterior foraminotomies. Using microsurgical instruments, the surgical approach exposes the lateral aspect of the spinal column through a small incision at the front of the neck in a naturally occurring crease. The affected nerve root is exposed, and a herniated disc or bone spur is removed to decompress the nerve. By removing only the herniated portion of the disc, the procedure is intended to preserve normal disc function and avoid bone fusion. As it utilizes a microsurgical technique that minimizes laminectomy and facet trauma, this technique does not require bone fusion or post-operative immobilization. However, there is a paucity of clinical studies to validate the effectiveness of this approach. The studies reported in the medical literature involve a small number of patients, are published by just one author, and a considerable portion of each article discusses only the technical aspects of the procedure.

Open Sacroiliac Fusion

Sacroiliac fusion involves bony fusion of the sacroiliac joint for stabilization. Sacroiliac joint (SIJ) fusion has been suggested as a possible treatment option for individuals with low back pain due to sacroiliac joint dysfunction or syndrome. This procedure may be performed by an open surgical approach or as a minimally invasive procedure in order to place plates and/or screws to develop a bony fusion across the SIJ for stabilization. There is insufficient scientific evidence to support use of sacroiliac fusion in treating LBP due to sacroiliac joint syndrome.

In the 1920’s, sacroiliac dysfunction was a common diagnosis and fusion of this joint was the most common form of back surgery. However, there is little evidence that the sacroiliac joint is a common source of back pain. European guidelines on the diagnosis and treatment of pelvic girdle pain (Vleeming et al, 2004) recommend against the fusion of sacroiliac joints. The guidelines note that severe traumatic cases of pelvic girdle pain can be an exception to this recommendation, but only when other non-operative treatment modalities have failed. In that case, pre-operative assessment with an external fixator for 3 weeks to evaluate longer lasting effects of fixation, is recommended (Wahlheim, 1984; Slatis and Eskola, 1989; Sturesson et al, 1999). The authors identified no controlled trials of sacroiliac fusion. Available evidence consists of cohort studies (level D evidence) (Smith-Petersen and Rogers, 1926; Gaenslen, 1927; Hagen, 1974; Olerud and Wahlheim, 1984; Waisbrod et al, 1987; Moore, 1995; Keating, 1995; Belanger and Dall, 2001; Berthelot et al, 2001; van Zwienen et al, 2004; Giannikas et al, 2004). The guidelines note that, in all reports of fusion surgery, an operation took place only on patients in whom non-operative treatment had been unsuccessful. The cohort studies included from 2 to 77 patients and the results were assessed by the authors as fair to excellent in 50 to 89% of the patients. However, controlled studies are necessary to reach firm conclusions about the effectiveness of this procedure in the treatment of back pain.

Guidelines on treatment of LBP from the Colorado Department of Labor and Employment (2005) state that sacroiliac joint fusion is of limited use in trauma and is considered to be under investigation for patients with typical mechanical LBP: “Until the efficacy of this procedure for mechanical low back pain is determined by an independent valid prospective outcome study, this procedure is not recommended for mechanical low back pain”.

Microdiskectomy

Discectomy (diskectomy) is the most common surgical treatment for ruptured or herniated discs, particularly of the lumbar spine, though it may also be used on the cervical or thoracic spine. During a discectomy, the surgeon removes the section of the disc that is protruding from the disc wall and any other disc fragments that may be pressing on a nerve root or the spinal cord. A discectomy may be “open” or it may be performed microscopically (known as a microdiscectomy). Both procedures allow for direct visualization of the vertebra, disc and other surrounding structures. The microdiscectomy utilizes a special microscope or magnifying instrument to view the disc and nerves, which makes it possible to remove the disc material through a smaller incision. This smaller incision reduces the risk of damage to the surrounding tissues, which decreases the potential complications.

Endoscopic Diskectomy

There is insufficient evidence from clinical studies proving additional benefits from using an endoscope for performing disc decompression (such as in percutaneous endoscopic diskectomy or endoscopic laser percutaneous diskectomy (LASE)). At this time there are no reliable clinical studies of endoscopic spinal surgery that have included an adequate comparison group of patients receiving open procedures. In addition, there is limited evidence on the long-term outcomes resulting from these endoscopic procedures. Gibson et al (2002), reporting on the results of a systematic review of studies on surgery for lumbar disc prolapse, explained that “[t]here is currently no evidence supporting endoscopic… treatment of disc prolapse”.

Yeung Endoscope Spine Surgery (Arthroscopic Microdiskectomy, Percutaneous Endoscopic Diskectomy With or Without Laser (PELD))

An arthroscopic microdiscectomy, also known as a percutaneous endoscopic discectomy (PED), has been proposed as another alternative to the traditional open procedure or the microdiscectomy. A cannula is inserted, with fluoroscopic guidance, near the spine through which an endoscope and very small surgical instruments are then inserted. The herniated portion of the disc can then be removed. This procedure does not allow direct visualization of the disc or surrounding tissues and is generally performed under conscious sedation, rather than general anesthesia. Examples of devices used in an arthroscopic microdiscectomy/percutaneous endoscopic discectomy include, but may not be limited to, the AccuraScope DND, Joimax iLESSYS, Joimax TESSYS or Yeung Endoscopic Spinal System (Y.E.S.S.).

Yeung Endoscopic Spinal Surgery (YESS) (also known as arthroscopic microdiskectomy or percutaneous endoscopic diskectomy (PELD)) is an endoscopic approach to lumbar disc surgery that involves a multi-channel scope and special access cannulae that allow spinal probing in a conscious patient, diagnostic endoscopy, and “minimally invasive surgery” (Yeung and Porter, 2002). The Yeung Endoscope Spine System (Y.E.S.S.) (Richard Wolf Surgical Instrument Corp., Vernon Hills, IL) or similar specialized instruments may be used to perform these procedures. The spinal endoscope is used to direct probing and targeted fragmentectomy of disc herniations. In addition, the approach may be used for foraminoplasty, where an endoscope-assisted laser is used to widen the exit route foramina of the lumbar spine and ablate any protruding portions of the intervertebral disk. Typically, procedures are performed at several levels of the spine, either simultaneously or in close temporal succession. Other adjunctive therapeutic procedures may be performed such as applying chemonucleolytic agents, lasers, radiofrequency technology, electrothermal energy, flexible mechanical instruments or intradiscal steroids. Supporters of arthroscopic microdiskectomy state that it provides visualization at the same time as application of therapeutic services. In addition, they argue that the ability to provoke pain while the patient is in the aware state and able to communicate during surgery allows the surgeon to better identify and treat the source of the patient’s back pain. However, there is inadequate evidence to determine whether the results of arthroscopic microdiskectomy are as durable or as effective as open spinal surgery. A particular concern is whether this microendoscopic approach allows for adequate visualization of the spine during surgery. Literature to date on arthroscopic microdiskectomy has been limited to review articles and reports of retrospective case series. There are no published prospective, RCTs of arthroscopic microdiskectomy, and there are no prospective studies with long-term follow-up. In addition, the studies of Y.E.S.S. that have been published thus far have been from a single investigator group, raising questions about the generalization of the findings. Thus, arthroscopic microdiskectomy does not meet Aetna’s criteria.

Minimally Invasive Lumbar Decompression Procedures

Minimally invasive approaches for laminectomy, laminotomy, foraminectomy or foraminotomy have also been proposed as a newer treatment option by some surgeons. They may utilize either an endoscopic or laparoscopic approach for the procedure, which allows direct visualization of the surgical field.

Additionally, percutaneous procedures have been proposed as an alternative surgical approach for laminectomy, laminotomy, foraminectomy or foraminotomy. The percutaneous procedures are generally performed in an outpatient setting with the individual awake but sedated. Percutaneous spinal procedures do not allow direct visualization of the surgical field. Examples of percutaneous image-guided decompression procedures for lumbar spinal stenosis are the MILD procedure and decompression with the Totalis Direct system, both of which utilize trocars to access the area of stenosis (resection of the ligamentum flavum).

The North American Spine Society defines an open procedure done through an incision of approximately one inch or more. Minimally invasive lumbar decompression is performed through small incisions of less than 1 inch. Minimally invasive lumbar decompression procedures include those performed under direct visualization using specialized tubular retractors, and procedures performed under indirect visualization.

These approaches are not supported by reliable evidence in the peer reviewed published medical literature. These centers typically advertise their “unique” methods of performing spine surgery through very small portals using specialized instruments that often have been developed by the centers themselves. These procedures are often performed while the patient is conscious under moderate sedation. Typically, several surgical procedures are performed at multiple levels simultaneously or on successive days until the patient reports pain relief or surgery is exhausted. Proponents argue that these procedures involve fewer anesthetic risks, a smaller incision, reduced blood loss, faster post-operative recovery and performance of surgery in an outpatient setting.

An important concern about this minimally invasive approach is the limited visualization of the spine, such that the surgeon cannot reliably identify and ensure complete removal all bone spurs and other structures impinging on nerves. In addition, the performance of several surgical procedures in close temporal succession does not allow adequate evaluation of the outcomes of one surgical procedure before subsequent surgical procedures are performed.

One center advertises that they manufacture special instruments and develop new techniques to perform complex microscopic laser spinal surgeries through portals of 1/4 to 1/2 of an inch under conscious sedation. They state that they have developed “unique” methods of performing endoscopic surgeries. The center states that they are the only facility that performs endoscopic spinal joint surgery, thoracic laser discectomy, endoscopic sacroiliac joint surgery, endoscopic hardware removal, or endoscopic bio-absorbable fusions or intradiscal stem cell therapy. The center also asserts that their unique minimally invasive spine surgery techniques are so advanced that patients who have failed other minimally invasive or conventional spine surgeries may benefit from their procedures. The center advertises that they have performed over 7,000 of these minimally invasive spinal surgeries. Although they state that they regularly publish their findings in peer-reviewed journals, what evidence they have published is limited to small, uncontrolled case series focusing on short-term followup (Haufe et al, 2008; Haufe and Mork, 2007; Haufe and Mork, 2006; Haufe and Mork, 2005; Haufe and Mork, 2004).

Another center makes similar claims for the effectiveness of unique endoscopic laser spinal surgical procedures performed under conscious sedation with patented instruments. The center performs spinal procedures using videoendoscopy and specially adapted surgical probes. Procedures include specialized methods of laser diskectomy, laser lumbar facet debridement, laser foraminoplasty, and laser debridement of spinal processes. The center’s website includes testimonials and a list of abstracts presented at meetings, but the center has not published the results of their procedures in peer-reviewed publications. The center recently announced initiation of an outcome study to evaluate outcomes of their procedures in persons with failed back syndrome.

Another center offers unique endoscopic laser methods of performing surgery for back and neck pain. The primary procedures include foraminotomy, laminotomy, percutaneous endoscopic discectomy, and facet thermal ablation. The center advertises the ability to complete all necessary evaluation, pre-operative preparation, surgery, and post-operative physical therapy within 1 week. The center advertises that advantages of their method of minimally invasive surgery includes no general anesthesia, no hospitalization, minimally invasive surgery, minimal scar tissue formation, and the availability of outpatient procedures. The center states that the most prominent difference between their techniques and that of other spinal centers is the endoscopic method in which they enter the body to minimize trauma, scar tissue formation, and healing times. The center states that their surgeons have performed approximately 10,000 surgeries collectively for over 10 years. Their website includes testimonials. However, they have not submitted their results for peer-review publication.

Minimally Invasive Lumbar Decompression (MILD)

MILD (Vertos Medical) is a new procedure for pain relief from symptomatic central lumbar canal stenosis. It entails limited percutaneous laminotomy and thinning of the ligamentum flavum in order to increase the critical diameter of the stenosed spinal canal.

In a retrospective study, Lingreen and Grider (2010) examined the minor adverse events and peri-procedural course associated with the MILD procedure. In addition, these researchers evaluated the effectiveness of the procedure with regard to pain relief and functional status. A total of 42 consecutive patients meeting MRI criteria for MILD underwent the procedure performed by 2 interventional pain management physicians working at the same center. The pre- and post-procedure VAS as well as markers of global function were recorded. Major and minor adverse events were tracked and patient outcomes reported. There were no major adverse events reported. Of the minor adverse events, soreness lasting 3.8 days was most frequently reported. No patients required over-night observation and only 5 required post-operative opioid analgesics. Patients self-reported improvement in function as assessed by ability to stand and ambulate for greater than 15 mins, whereas prior to the procedure 98% reported significant limitations in these markers of global functioning. Visual analog pain scores were significantly decreased by 40% from baseline; 86% of the patients reported that they would recommend the MILD procedure to others. The authors concluded that the MILD procedure appears to be a safe and likely effective option for treatment of neurogenic claudication in patients who have failed conservative therapy and have ligamentum flavum hypertrophy as the primary distinguishing component of the stenosis.

this was a preliminary report encompassing only a 6-week follow-up, and
there was no control group.

Deer and Kapural (2010) assessed the acute safety of the MILD procedure. Manual and electronic chart survey was conducted by 14 treating physicians located in 9 states within the United States on 90 consecutive patients who underwent the MILD procedure. Patients requiring lumbar decompression via tissue resection at the peri-laminar space, within the inter-laminar space and at the ventral aspect of the lamina were treated. Data collected included any complications and/or adverse events that occurred during or immediately following the procedure prior to discharge. Of 90 procedures reviewed, there were no major adverse events or complications related to the devices or procedure. No incidents of dural puncture or tear, blood transfusion, nerve injury, epidural bleeding, or hematoma were observed. Limitations of this study were:

data were not specifically collected; however, regardless of difficulty, in this series none of the procedures was aborted and none resulted in adverse events, and
efficacy parameters were not collected in this safety survey.

The authors concluded that this study demonstrates the acute safety of the MILD procedure with no report of significant or unusual patient complications. They noted that additional studies are currently underway to establish complication frequency and longer-term safety profile associated with this treatment.

In a prospective, case-series study, Mekhail et al (2012) reported findings of consecutive LSS patients who presented with neurogenic claudication and were treated with percutaneous lumbar decompression. Efficacy was evaluated using the Pain Disability Index (PDI) and Roland-Morris Disability Questionnaire. Pre- and post-procedure standing time, walking distance, and VAS were also monitored. Significant device- or procedure-related AEs were reported. The MILD procedure was successfully performed on 40 patients. At 12 months, both PDI and Roland-Morris showed significant improvement of 22.6 points (ANOVA, p < 0.0001) and 7.7 points (ANOVA, p < 0.0001), respectively. Walking distance, standing time, and VAS improvements were also statistically significant, increasing from 246 to 3,956 feet (ANOVA, p < 0.0001), 8 to 56 mins (ANOVA, p < 0.0001), and 7.1 to 3.6 points (ANOVA, p < 0.0001), respectively. Tukey HSD test found improvement in all 5-outcome measures to be significant from baseline at each follow-up interval. No significant device- or procedure-related AEs were reported. The authors concluded that this study demonstrated significant functional improvement as well as decreased disability secondary to neurogenic claudication after the MILD procedure. Safety, cost-effectiveness, and QOL outcomes were best compared with comprehensive medical management in a randomized controlled fashion and, where ethical, to open lumbar decompression surgery.

The Centers for Medicare & Medicaid Services (CMS, 2014) concluded that percutaneous image guided lumbar decompression (PILD) for lumbar spinal stenosis (LSS) is not reasonable and necessary. The scope of the CMS national coverage analysis (NCA) included a review of the evidence on whether percutaneous image-guided lumbar decompression for LSS provides improved health outcomes in Medicare beneficiaries. The analysis also included the proprietary procedure mild®. CMS identified a number of studies related to the PILD procedure for LSS. The majority of studies were case series which have inherent limitations in providing a level of reliable evidence of benefit for a procedure, especially a procedure addressing pain. The case series for the PILD procedure suffered from additional limitations in failing to report information important for anyone to assess the clinical utility of this procedure for a particular patient. The one RCT had a small enrollment and major design flaws that called into question the results of the trial. On January 9, 2014, CMS issued a Medicare National Coverage Determination (NCD) which allows coverage of PILD for LSS under Coverage with Evidence Development (CED) with certain conditions. The NCD required a prospective, randomized, controlled clinical trial (RCT) design. On December 7, 2016, CMS expanded this NCD to allow coverage of PILD for LSS under CED in a prospective longitudinal study using an FDA-approved/cleared device that successfully completed a CMS-approved RCT with certain conditions (CMS, 2021).

Zaina et al (2016) reported on a Cochrane review evaluating the effectiveness of different types of surgery compared with different types of non-surgical interventions in adults with symptomatic lumbar spinal stenosis..Low-quality evidence from one small study suggested no differences at six weeks in the Oswestry Disability Index for patients treated with minimally invasive mild decompression versus those treated with epidural steroid injections (MD 5.70, 95% CI 0.57 to 10.83; 38 participants). Zurich Claudication Questionnaire (ZCQ) results were better for epidural injection at six weeks (MD -0.60, 95% CI -0.92 to -0.28), and visual analogue scale (VAS) improvements were better in the mild decompression group (MD 2.40, 95% CI 1.92 to 2.88). At 12 weeks, many cross-overs prevented further analysis. The authors concluded that “we have very little confidence to conclude whether surgical treatment or a conservative approach is better for lumbar spinal stenosis, and we can provide no new recommendations to guide clinical practice. However, it should be noted that the rate of side effects ranged from 10% to 24% in surgical cases, and no side effects were reported for any conservative treatment. No clear benefits were observed with surgery versus non-surgical treatment.”

Benyamin et al (2016) concluded that 1-year results of a RCT demonstrated that MILD was statistically superior to epidural steroid injections (ESI) in the treatment of LSS patients with neurogenic claudication and verified central stenosis due to ligamentum flavum hypertrophy. Primary and secondary efficacy outcome measures achieved statistical superiority in the MILD group compared to the control group. With 95 % of patients in this study presenting with 5 or more LSS co-factors, it is important to note that patients with spinal co-morbidities also experienced statistically significant improved function that was durable through 1 year. The main drawbacks of this study included the lack of patient blinding due to significant differences in treatment protocols between study arms, including multiple ESI procedures during the study period versus one MILD procedure. Also, adjunctive pain therapy within the lumbar region was restricted, and therefore responder rates may be lower for both study groups compared to those outside of study confines. Study enrollment was not limited to patients that had never received ESI therapy.

In a prospective, multi-center, randomized controlled clinical study, Staats and colleagues (2018) evaluated the long-term durability of the minimally invasive lumbar decompression (MILD) procedure in terms of functional improvement and pain reduction for patients with lumbar spinal stenosis and neurogenic claudication due to hypertrophic ligamentum flavum. This was a report of 2-year follow-up for MILD study patients. These investigators compared outcomes for 143 patients treated with MILD versus 131 treated with epidural steroid injections (ESI). Follow-up occurred at 6 months and at 1 year for the randomized phase and at 2 years for MILD subjects only; ODI, NPS, and ZCQ were used to evaluate function and pain. Safety was evaluated by assessing incidence of device-/procedure-related AEs. All outcome measures demonstrated clinically meaningful and statistically significant improvement from baseline through 6-month, 1-year, and 2-year follow-ups. At 2 years, ODI improved by 22.7 points, NPS improved by 3.6 points, and ZCQ symptom severity and physical function domains improved by 1.0 and 0.8 points, respectively. There were no serious device-/procedure-related AEs, and 1.3% experienced a device-/procedure-related AE. The authors concluded that MILD showed excellent long-term durability, and there was no evidence of spinal instability through 2-year follow-up. Re-operation and spinal fracture rates were lower, and safety was higher for MILD versus other lumbar spine interventions, including interspinous spacers, surgical decompression, and spinal fusion. These researchers stated that given the minimally invasive nature of this procedure, its robust success rate, and durability of outcomes, MILD is an excellent choice for 1st-line therapy for select patients with central spinal stenosis suffering from neurogenic claudication symptoms with hypertrophic ligamentum flavum.

The authors stated that the limitations of this study included the lack of a control group at 2-year follow-up. The randomized controlled portion of the study concluded at the primary end-point of 1 year, and supplementary follow-up through 2 years was conducted for the MILD patient group only. This study did not compare efficacy directly with open surgical approaches, including lumbar decompression, fusion, or spacers. Other limitations included the lack of patient blinding due to considerable differences in treatment protocols, a potentially higher non-responder rate for both groups versus standard-of-care due to study restrictions on adjunctive pain therapies, and study enrollment was not limited to patients that had never received ESI therapy.

Deer et al (2019) noted that lumbar spinal stenosis (LSS) can lead to compression of neural elements and manifest as low back pain (LBP) and leg pain. LSS has traditionally been treated with a variety of conservative (pain medications, physical therapy, epidural spinal injections) and invasive (surgical decompression) options. Recently, several minimally invasive procedures have expanded the therapeutic options. The Lumbar Spinal Stenosis Consensus Group convened to examine the peer-reviewed literature as the basis for making minimally invasive spine treatment (MIST) recommendations. A total of 11 consensus points were defined with evidence strength, recommendation grade, and consensus level using U.S. Preventive Services Task Force (USPSTF) criteria. The Consensus Group also created a treatment algorithm. Literature searches yielded 9 studies (2 randomized controlled trials [RCTs]; 7 observational studies, 4 prospective and 3 retrospective) of MISTs, and 1 RCT for spacers. The LSS treatment choice is dependent on the degree of stenosis; spinal or anatomic level; architecture of the stenosis; severity of the symptoms; failed, past, less invasive treatments; previous fusions or other open surgical approaches; and patient co-morbidities. There is Level I evidence for percutaneous image-guided lumbar decompression as superior to lumbar epidural steroid injection, and 1 RCT supported spacer use in a non-inferiority study comparing 2 spacer products currently available. The authors concluded that MISTs should be used in a judicious and algorithmic fashion to treat LSS, based on the evidence of efficacy and safety in the peer-reviewed literature. The MIST Consensus Group recommended that these procedures be used in a multi-modal fashion as part of an evidence-based decision algorithm.

Aldahshory et al (2020) stated that the classic laminectomy for spinal decompression was the treatment of choice of the degenerative lumbar canal stenosis (LCS). Many surgeons prefer to add instrumented lumbar fusion to avoid future instability after the removal of posterior elements. Adding fusion is associated with more bleeding and longer periods of hospitalization. Minimally invasive lumbar decompression (MILD) has been advocated for successful decompression with less bleeding loss and shorter hospitalization. These researchers compared the clinical outcomes of 2 different treatment modalities for degenerative LCS: the classic laminectomy with postero-lateral transpedicular screw fixation and the MILD. A total of 50 patients with degenerative LCS were randomized from 2 institutions: Ain Shams University Hospital and Arab Contractors Medical Center, who underwent surgeries for degenerative LCS between 2016 and 2018 with 1-year follow-up. The study compared 2 cohorts: Group A – 25 patients underwent classic lumbar laminectomy with postero-lateral transpedicular fixation, and Group B – 25 patients underwent MILD. There were no statistically significant differences between both treatment modalities in the VAS for leg pain and back pain, the patient satisfaction index, and the ODI after 1 year. The fusion operations were associated with higher estimates of blood loss, longer hospital stay, and more financial costs. The authors concluded that MILD had the same satisfactory results as classic laminectomy with postero-lateral fixation for the treatment of degenerative LCS with less bleeding loss and shorter hospitalization. Since the results were comparable, MILD was suggested in low-income countries as Egypt for economic reasons.

The authors stated that this study had limitations as 1-year follow-up was insufficient to evaluate the re-operation rate in case of adding fusion. Other limitations included small sample size (n = 25 in the MILD group) and lack of information regarding the BMI of each patient and the associated co-morbidities.

Ricciardi et al (2020) noted that chronic LBP can be due to many different causes, including degenerative spondylolisthesis (DS). For patients who do not respond to conservative management, surgery remains the most effective treatment. Open laminectomy alone and laminectomy and fusion (LF) for DS have been widely investigated, however, no meta-analyses have compared minimally invasive decompression with posterior elements preservation (MID) techniques and LF. Minimally invasive techniques might provide specific advantages that were not recognized in previous studies that pooled different decompression strategies together. This was a systematic review and meta-analysis, according to the PRISMA statement, of comparative studies reporting surgical, clinical and radiological outcomes of MID and LF for DS. A total of 3,202 papers were screened and 7 were finally included in the meta-analysis. MID is associated with a shorter surgical duration and hospitalization stay, and a lower intra-operative blood loss and residual LBP; however, the residual disability grade was lower in the LF group; complication rates were similar between the 2 groups . The rate of adjacent segment degeneration was lower in the MID group, whereas data on radiological outcomes were heterogeneous and not suitable for data-pooling. The authors concluded that this meta-analysis suggested that MID might be considered as an effective alternative to LF for DS. Moreover, these researchers stated that further clinical trials are needed to confirm these findings, better investigate radiological outcomes, and identify patient subgroups that may benefit the most from specific techniques.

Fornari et al (2020) stated that degenerative LSS is a progressive disease with potentially dangerous consequences that affect QOL. Despite the detailed literature, natural history is unpredictable. This uncertainty presents a challenge making the correct management decisions, especially in patients with mild-to-moderate symptoms, regarding conservative or surgical treatment. This article focused on conservative treatment for degenerative LSS. To standardize clinical practice worldwide as much as possible, the World Federation of Neurosurgical Societies Spine Committee held a consensus conference on conservative treatment for degenerative LSS. A team of experts in spinal disorders reviewed the literature on conservative treatment for degenerative LSS from 2008 to 2018 and drafted and voted on a number of statements. During 2 consensus meetings, 14 statements were voted on. The Committee agreed on the use of physical therapy for up to 3 months in cases with no neurologic symptoms. Initial conservative treatment could be applied without major complications in these cases. In patients with moderate-to-severe symptoms or with acute radicular deficits, surgical treatment is indicated. The efficacy of epidural injections is still debated, as it showed only limited benefit in patients with degenerative LSS. The authors concluded that a conservative approach based on therapeutic exercise may be the 1st choice in patients with LSS except in the presence of significant neurologic deficits. Treatment with instrumental modalities or epidural injections is still debated. These researchers stated that further studies with standardization of outcome measures are needed to reach high-level evidence conclusions. This review noted that there is low-quality level of evidence for minimally invasive surgical decompression provides better pain reduction and improves functional mobility versus epidural steroid injections (citing the study by Zaina et al, 2016). Zaina et al (2016) concluded that they had very little confidence to conclude whether surgical treatment or a conservative approach is better for LSS, and they could provide no new recommendations to guide clinical practice. However, it should be noted that the rate of side effects ranged from 10 % to 24 % in surgical cases, and no side effects were reported for any conservative treatment. No clear benefits were observed with surgery versus non-surgical treatment. These findings suggested that clinicians should be very careful in informing patients regarding possible therapeutic options, especially given that conservative treatments have resulted in no reported side effects. These researchers stated that high-quality research is needed to compare surgical versus conservative care for individuals with LSS. For the study by Deer et al (2019), this review noted that short- to intermediate-term benefit of epidural injections for symptomatic treatment of LSS. Benefit of caudal and interlaminar injections (local anesthetic only and local anesthetic with steroid) and transforaminal injections of local anesthetic with or without steroid. Patients exhibiting shorter-term relief of less than 3 months should not proceed with further injection therapy but rather continue down treatment algorithm to a therapeutic option directed at decompression.

Merkow et al (2020) noted that symptomatic LSS is a condition affecting a growing number of individuals resulting in significant disability and pain. Traditionally, therapeutic options have consisted of conservative measures such as physical therapy, medication management, epidural injections and percutaneous adhesiolysis, or surgery. There exists a treatment gap for patients failing conservative measures who are not candidates for surgery. Minimally invasive lumbar decompression (MILD) and interspinous process device (IPD) with Superion represent minimally invasive novel therapeutic options that may help fill this gap in management. These investigators carried out a literature review to separately evaluate these procedures and examined their safety and effectiveness. The authors concluded that the available evidence for MILD and Superion has been continuously debated. Overall, it is considered that while the procedures are safe, there is only modest evidence for effectiveness. For both procedures, these researchers have reviewed 13 studies. Based on the available evidence, MILD and Superion are safe and modestly effective minimally invasive procedures for patients with symptomatic LSS. They stated that these procedures may be incorporated as part of the continuum of therapeutic options for patients meeting clinical criteria.

Furthermore, an UpToDate review on “Lumbar spinal stenosis: Treatment and prognosis” (Levin, 2021) states that “Minimally invasive decompression – There is long-standing interest in the development of less invasive decompression procedures, such as percutaneous lumbar decompression and/or minimally invasive lumbar decompression, which appear in observational studies to have lower complication rates than traditional surgical techniques. It is unclear if these newer procedures offer benefit in terms of improved symptoms and function or fewer complications in routine practice compared with standard decompression with laminectomy”.

Mekhail et al (2021) noted that minimally invasive lumbar decompression (the MILD Procedure; Vertos Medical, Aliso Viejo, CA) has been shown to be safe and effective for the treatment of lumbar spinal stenosis (LSS) patients with hypertrophic ligamentum flavum as a contributing factor. In a retrospective, longitudinal, observational cohort study, these researchers examined the long‐term durability of the MILD Procedure through 5‐year follow‐up. Pain relief and opioid medications use during 12‐month follow‐up were also assessed. All patients diagnosed with LSS secondary to ligamentum flavum hypertrophy who underwent the MILD Procedure from 2010 through 2015 at the Cleveland Clinic Department of Pain Management were included in this trial. The primary outcome measure was the incidence of open lumbar decompression surgery at the same level(s) as the MILD Procedure during 5‐year follow‐up. Secondary outcome measures were the change in pain levels using the Numeric Rating Scale (NRS) and opioid medications utilization using Morphine Milligram Equivalent (MME) dose per day from baseline to 3, 6, and 12 months post‐MILD Procedure; and post-procedural complications (minor or major) were also collected. A total of 75 patients received the MILD Procedure during the protocol‐defined time-period and were included in the trial. Only 9 (12 %) out of 75 patients required lumbar surgical decompression during the 5‐year follow‐up period. Subjects experienced statistically significant pain relief and reduction of opioid medications use at 3, 6, and 12 months compared to baseline. The authors concluded that based on their analysis, the MILD Procedure was durable over 5 years and may allow elderly patients with symptomatic LSS to avoid lumbar decompression surgery while providing significant symptomatic relief. These researchers stated that these findings highlighted the potential role of the MILD procedure to significantly impact patients’ quality of life (QOL) while avoiding a major health and economic burden.

The authors stated that this study bore all the drawbacks of retrospective data analysis; however, every effort was made to ensure the accuracy of data. Telephone calls were made to confirm data if needed. Possible other confounding factors affecting the incidence of subsequent open surgery, reported pain scores, and opioid consumption may not have been measured. Missing follow‐up data for a few patients may still pose a limitation for this analysis.

In a prospective, randomized controlled trial (RCT), Deer et al (2021) examined patients aged 50 to 80 years treated with the MILD procedure plus conventional medical management (CMM), compared to those treated with CMM alone, as the active control. Walking tolerance test outcomes and incidence of subsequent disallowed procedures provided objective real-world outcome data. The incidence of device or procedure-related adverse events (AEs) was analyzed. Follow-up includes 6-month, 1-year and 2-year assessments, with 1-year being primary. Patients in the MILD+CMM group were followed at 3, 4, and 5 years. This was a report of interim 6-month outcomes. Of 155 patients enrolled at 19 U.S. interventional pain management centers, 78 were allocated to CMM alone, and 77 to MILD+CMM. At 6-months, the validated walking tolerance test demonstrated statistical superiority of MILD+CMM versus CMM alone (p < 0.001). The incidence of patients receiving a subsequent disallowed procedure, and thereby considered treatment failures in their study group, was statistically significantly higher in CMM alone versus MILD+CMM (p < 0.001). There were no device or procedure-related AEs in either group. The authors concluded that at 6-months, the MILD Procedure combined with CMM provided statistically superior objective real-world outcomes versus CMM alone. There were no device or procedure-related AEs reported in either study group. With its excellent safety profile and superior efficacy, the MILD Procedure is uniquely positioned as early 1st-line therapy.

The authors stated that drawbacks of this trial included the lack of blinding, which was not possible due to the use of an active comparator that allowed for a broad range of both conservative and interventional treatments in both study groups. It was anticipated that patients in both arms may continue to receive CMM therapies throughout the study period. The real-world nature of this study, which allowed the use of CMM in both study arms at the full discretion of the investigator, was also a limitation due to use of various standard of care treatment algorithms. All CMM treatments as well as subsequent disallowed procedures were recorded. Patients who received a disallowed procedure remain in the study and were assessed at all follow-ups. Furthermore, this was a 6-month interim report; long-term follow-up (3 to 5 years) data are needed; it’s also unclear whether the statistical superiority of the MILD+CMM over CMM alone would translate into clinical superiority.

Pope et al (2021) noted that low-back pain (LBP) with accompanying neurogenic claudication is a common diagnosis in pain and spine centers around the world, with an evolving algorithm of treatment. One option for the treatment of neurogenic claudication by decompressive strategies centers on percutaneous direct decompressive techniques. Although commonly used in clinical practice, there have been no formal investigations examining the safety of percutaneous direct decompression without the use of an epidurogram and relying on osteal landmarks. In a retrospective, single-center, quantitative analysis, these investigators examined the safety of percutaneous direct decompression carried out without the use of the epidurogram. After an Investigational Review Board (IRB) exemption had been obtained from the Western IRB, data were retrospectively analyzed from July 2018 to August 2020 on patients who had undergone percutaneous direct decompression using the Mild procedure in a single center by a single physician. Data were analyzed quantitatively for reported complications within 3 months of the procedure, including nerve injury, hematoma, infection, death, or allergic reaction to contrast use. Chart review yielded 147 individual patients who had undergone percutaneous direct decompression from July 2018 to August 2020. In this data set, women out-numbered men, with an average age of 76 years, with L4 to L5 followed by L3 to L4 being the most common levels decompressed. Of the 147 patients was performed, utilizing an epidurogram versus no epidurogram for decompression, with no complications. These data were the 1st to describe the safety of percutaneous direct lumbar decompression without the use of contrast. The authors concluded that the findings of this study strongly suggested the use of an epidurogram was not necessary for the safe decompression of a patient with symptomatic spinal stenosis and neurogenic claudication utilizing percutaneous direct decompression.

The authors stated that drawbacks of this study included the retrospective nature of the study. Although the MiDAS ENCORE study of 149 patients indicated a re-operation rate of 5.6 % at 2-year follow-up and an AE rate of 1.3 %, this single-site study may not translate to a broader application of the percutaneous direct decompressive method using a single incision and absence of an epidurogram. Furthermore, effectiveness was not examined for either group, as this study was focused on patient safety. Percutaneous decompression technique variance and effectiveness comparisons are under way. These researchers stated that prospective studies need to be performed with a direct comparison of safety and effectiveness of the new technique described in this cohort.

Deer et al (2022) provided real-world outcome data for patients with LSS suffering from neurogenic claudication secondary to hypertrophic ligamentum flavum. The MOTION Study is a prospective, multi-center RCT comparing the MILD Procedure as a 1st-line therapy in combination with non-surgical CMM versus CMM alone as the active control. Patients in the test group received the MILD Procedure at baseline. Both the MILD+CMM group and the control group were allowed unrestricted access to conventional real-world therapies. Patient-reported outcomes included the ODI, the Zurich Claudication Questionnaire, and the Numeric Pain Rating Scale. A validated Walking Tolerance Test, the incidence of subsequent lumbar spine interventions, and the occurrence of AEs were used to measure objective outcomes. A total of 69 patients in each group were analyzed at 1-year follow-up. No device- or procedure-related AEs were reported in either group. Results from all primary and secondary outcome measures showed statistical significance in favor of MILD+CMM. The authors concluded that 1-year results of this study demonstrated superiority of MILD+CMM over CMM alone for patients with LSS who were suffering from neurogenic claudication secondary to hypertrophic ligamentum flavum. Use of the validated Walking Tolerance Test to objectively measure increased ability to walk without severe symptoms provided evidence of statistically significantly better outcomes for MILD+CMM than for CMM alone. With no reported device or procedure-related AEs, the long-standing safety profile of the MILD Procedure was re-affirmed. These investigators stated that the MILD procedure is a safe, durable, minimally invasive procedure that has been shown to be effective as an early interventional therapy for patients suffering from symptomatic LSS.

These researchers stated that although the MOTION Study was designed to include a patient population commonly seen every day in the clinic, the inclusion of numerous CMM therapeutic options chosen at the investigator’s discretion provided a broad range of therapeutic options and sequencing, as is encountered in the real world. This limited control over the use of CMM, though intended in the study design, may be viewed as a study limitation. The use of CMM in both arms of this study simulates real-world practice, but it also may result in confounding, as patients were treated on the basis of routine use of the MILD Procedure in a typical clinic setting. In day-to-day practice, the MILD Procedure is not used alone but in conjunction with other conservative therapies. The non-blinded nature of the study could also be considered a limitation. The use of objective real-world outcome measures, together with independent physicians in the role of medical monitor, clinical events adjudicator, and study principal investigator, were intended to limit study bias. This was a 1-year interim report; long-term follow-up (3 to 5 years) data are needed; it’s also unclear whether the statistical superiority of the MILD+CMM over CMM alone would translate into clinical superiority.

In a retrospective study, Pryzbylkowski et al (2022) examined a modified algorithm for the treatment of LSS with hypertrophic ligamentum flavum using minimally-invasive lumbar decompression (mild) with a focus on earlier intervention. Records of 145 patients treated with mild after receiving 0 to 1 epidural steroid injection (ESI) or 2+ ESIs were reviewed. Pain assessments as measured by VAS scores were recorded at baseline and 1-week and 3-month follow-ups. Improvements in VAS scores at follow-ups compared with baseline were significant in both groups. No statistically significant differences were found between the 2 groups. The authors concluded that multiple ESIs before the mild procedure showed no benefit. A modified algorithm to perform mild immediately upon diagnosis or after the failure of the 1st ESI is recommended. These researchers noted that with a safety profile similar to ESI, mild offered the potential for long-term symptom relief without first subjecting LSS patients to multiple ESI treatments.

Hagedorn et al (2022) stated that LSS affects more than 200,000 adults in the U.S., resulting in about 38,000 operations among the Medicare population and greater than $1.5 billion in hospital bills alone. Fortunately, minimally invasive lumbar decompression (MILD) and the Superion indirect decompression System have shown lasting benefit and cost savings compared to more aggressive surgical options. In a retrospective study, these investigators determined the rate of lumbar decompression surgery following the MILD and Superion procedures. This was a pooled retrospective review of LSS patients who received MILD and/or Superion procedures between January 2011 and July 2019. Adult patients with CPT codes for MILD and Superion procedures were identified. Patients were included if they had a follow-up visit at least 2 years from the procedure date, preprocedural MRI results, and surgical notes. A total of 199 patients were included in the final analysis, of which 57 patients (28.6 %) underwent MILD procedure only, 124 patients (62.3 %) underwent Superion only, and 18 patients (9.0 %) underwent a MILD procedure initially followed by a Superion procedure. Two patients had a MILD procedure performed twice at the same level at separate encounters. A total of 4 patients in the entire cohort (2.0 %; MILD 5.3 %, Superion 0.8 %) underwent subsequent lumbar spine surgery when followed for at least 2 years. It was notable that some of these patients may not have been surgical candidates; and this may have skewed the results. The authors concluded that patients undergoing minimally invasive decompression treatment of LSS exhibited low rates of subsequent open surgery that potentially resulted in cost savings and a reduction in severe AEs. The reason for low surgical rate may reflect improvement in their symptoms, a preference to avoid surgery, or being deemed not a surgical candidate.

Deer et al (2024) stated that the MOTION study is designed to measure the impact of percutaneous image-guided lumbar decompression as a 1st-line treatment on patients otherwise receiving real-world conventional medical management for LSS with neurogenic claudication secondary to hypertrophic ligamentum flavum. This prospective, multi-center RCT employs objective and patient-reported outcome measures (PROMs) to compare the combination of the MILD® percutaneous treatment and non-surgical conventional medical management (CMM) to CMM alone. Test group patients received the MILD procedure following study enrollment. Test and control groups were allowed conventional conservative therapies and low-risk interventional therapies as recommended by their physicians. Subjective outcomes included the ODI, Numeric Pain Rating (NPR) Scale, and Zurich Claudication Questionnaire. Objective outcomes included a validated Walking Tolerance Test, the rate of subsequent lumbar spine interventions, and safety data. Two-year follow-up included 64 MILD + CMM and 67 CMM-alone patients. All outcome measures showed significant improvement from baseline for MILD + CMM, whereas the majority of CMM-alone patients had elected to receive MILD treatment or other lumbar spine interventions by 2 years, precluding valid 2-year between-group comparisons. Neither group reported any device- or procedure-related AEs. The authors concluded that the durability of MILD + CMM for this patient population was shown for all effectiveness outcomes through 2 years. Improvements in walking time from baseline to 2 years for patients treated with MILD + CMM were significant and substantial. The lack of reported device or procedure-related AEs reinforced the strong safety profile of the MILD procedure. These results provided support for early interventional treatment of symptomatic LSS with the MILD procedure.

The authors stated that the design of the MOTION Trial was intended to reflect the real-world environment in the clinic setting, including the patient population and the variety of CMM therapeutic options available to the investigator to employ at their discretion. As a consequence, the variability in type and number of CMM treatments may be viewed as a drawback. And while the use of CMM in both groups in this study simulates real-world practice, the type and frequency of CMM needed for each of the 2 groups could result in confounding, as patients in the CMM-alone group may have received systematically more CMM. Another limitation was the loss of patient performance evaluations in the treatment groups due to cross-over to MILD or other disallowed procedures, especially in the CMM-alone group, which resulted in unusable 2-year results for continuous outcomes in that group and precluded between-group comparisons for those outcomes. The choice of the MILD procedure for most subsequent lumbar spine interventions (SLSIs) could be viewed as a potential bias toward the treatment group; however, no restrictions were placed on any SLSI options.

Laser Diskectomy

Laser discectomy is also known as laser-assisted discectomy, laser disc decompression or laser-assisted disc decompression (LADD). Though this procedure is called a discectomy, it does not actually remove the disc, but utilizes a laser to “vaporize” a small portion of the nucleus pulposus in order to purportedly decompress a herniated disc. Laser discectomy may be performed either laparoscopically or percutaneously.

Laser diskectomy involves the use of a laser to vaporize a small portion of the nucleus pulposus in order to decompress a herniated disc. In laparoscopic laser diskectomy, the procedure is done through a laparoscope, which allows visualization of the disc, disc space and other structures. The surgeon places a laser through a delivery device that has been directed under radiographic control to the disc. The annulus of the disc is opened and is then excised with a laser device which is inserted through the laparoscope. It uses many of the same techniques used in automated percutaneous discectomy. An endoscope may be used in conjunction with this procedure to visualize the disc space and nucleus pulposus, or the procedure may be done percutaneously. By contrast, percutaneous disc decompression uses an x-ray to localize the tip of the needle/trocar to ensure that it is in the appropriate level and location. Percutaneous laser discectomy is performed under a local anesthetic. Under x-ray (fluoroscopic) guidance, a needle is inserted through the skin into the disc. A flexible quartz fiber is then threaded through the needle and into the disc, which delivers the laser energy.

The mechanism of action for pain relief in LADD is not well understood; most believe that the primary mechanism of pain reduction after LADD is its decrease in intradiscal pressure. According to the literature, laser-assisted disc decompression appears to be a safe procedure, but studies have not compared it to open surgical alternatives or other percutaneous methods. Randomized controlled trials are needed to compare current standard alternatives to both LADD and conservative treatment. A Cochrane review of surgical procedures for lumbar disc herniation concluded that “[t]here is currently no evidence supporting endoscopic (micro-suction) or laser treatment of disc prolapse” (Gibson et al, 2002). A systematic review of the literature on percutaneous endoscopic laser discectomy for the Royal Australasian College of Surgeons (Boult et al, 2000) reached similar conclusions: “Given the extremely low level of evidence available for this procedure it was recommended that the procedure be regarded as experimental until the results are available from a controlled clinical trial, ideally with random allocation to an intervention and control group”.

An assessment of laser lumbar diskectomy conducted for the National Institute of Clinical Excellence (NICE, 2003) concluded that current evidence on the safety and efficacy of laser lumbar discectomy does not appear adequate to support the use of this procedure without special arrangements for consent and for audit or research. A systematic evidence review by Jordan et al (2003) similarly concluded that the effectiveness of laser diskectomy is “unknown”.

Microdiscectomy

Microdiscectomy refers to removal of protruding disc material, using an operating microscope to guide surgery. Dent (2001) recently assessed the evidence supporting the use of microdiscectomy for prolapsed intervertebral disc, and found no evidence of differences in clinical outcomes between microdiscectomy and standard open discectomy. A Cochrane review found evidence that microdiscectomy takes longer to perform than standard open discectomy (Gibson et al, 2002). The review found no evidence of difference in short- or long-term symptom relief or complications, or length of inpatient stay. Similarly, a systematic assessment of the literature by Jordan et al (2003) concluded that microdiskectomy has not been shown to be more effective than standard diskectomy.

Microendoscopic Discectomy

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Microendoscopic discectomy (MED) procedure combines conventional lumbar microsurgical techniques with endoscopy and is performed at an outpatient setting. It is employed for the treatment of lumbar spine stenosis and lumbar disc herniation. It has been suggested that MED is less invasive (no damage to muscle, bone or soft tissue) compared with traditional open microdiscectomy. Moreover, MED allegedly allows an early return to work. However, this endoscopic procedure is difficult because of the limited exposure and 2-dimensional video display. The potential injury of the nerve root and prolonged surgical time remain as matters of serious concern. Currently, there is insufficient evidence to support the clinical value of this procedure especially its long-term effectiveness.

Muramatsu et al (2001) examined if MED was minimally invasive with respect to the nerve roots, cauda equina, and paravertebral muscles by comparing the post-operative magnetic resonance imaging findings in patients treated by MED and the conventional Love’s method. The authors concluded that MED had an effect on the nerve roots and cauda equina that was comparable with that of Love’s method. The magnetic resonance images of the route of entry failed to show that MED is appreciably less invasive with respect to the paravertebral muscles. Furthermore, in a review on the various minimally invasive procedures available for the treatment of lumbar disc disease, Maroon (2002) stated that although all percutaneous techniques (including MED) have been reported to yield high success rates, to date no studies have demonstrated any of these to be superior to microsurgical discectomy, which continues to be regarded as the standard with which all other techniques must be compared.

Far Lateral Microendoscopic Diskectomy (FLMED)

Extra-foraminal lumbar disc herniations (ELDHs) at the lumbo-sacral junction are an uncommon cause of L5 radiculopathy. The surgical anatomy of the extra-foraminal space at L5 to S1 is challenging for the various open surgical approaches that have been described for ELDHs in general. Reports specifically describing minimally invasive surgical approaches to lumbo-sacral ELDHs are lacking.

There is currently insufficient evidence to support the use of far lateral microendoscopic discectomy (FLMED). O’Toole and colleagues (2007) reported the novel use of far lateral microendoscopic discectomy (FLMED) to lumbo-sacral ELDH. To better define the unique anatomical features of extra-foraminal approaches to the lumbo-sacral junction as they apply to minimal access techniques. A cadaveric investigation a well as a clinical case were performed, and a thorough review of the literature was conducted. A single patient with an extra-foraminal disc herniation at the lumbo-sacral junction underwent evaluation and surgery. The patient’s self-reported pain levels were documented. Physiologic outcome was judged on pre- and post-operative motor and sensory examinations. Functional capacity was assessed by work status and ability to perform activities of daily living. Far lateral microendoscopic discectomy was performed in 2 fresh human cadavers at the lumbo-sacral junction. Qualitative assessments of the surgical anatomy were made, and intra-operative fluoroscopy and endoscopic photographs were obtained to document the findings. A patient with refractory pain and sensori-motor deficits from compression of the L5 nerve root by an ELDH underwent FLMED. The literature was carefully reviewed for the epidemiology of ELDHs at the lumbo-sacral junction and the surgical techniques used to treat them. The postero-lateral surgical corridor to the lumbo-sacral disc was consistently constrained by the sacral ala and to a lesser extent the lateral facet and L5 transverse process. Resection of the superior ala exposed the exiting nerve root and provided ample access to the disc. In the clinical case, the patient enjoyed immediate pain relief, was discharged in 3 hours, and returned to full work and social activities. Follow-up neurological examination revealed no sensory or motor deficit. The authors concluded that FLMED offers a safe and effective approach to ELDHs at the lumbo-sacral junction by combining satisfactory visualization for adequate resection of the sacral ala with the benefits of reduced tissue injury and faster recovery times that accompany minimally invasive techniques.

Pirris and colleagues (2008) noted that surgical access to ELDHs is complicated due to the unique anatomical constraints of the region. Minimizing complications during microdiscectomies at the level of L5 to S1 in particular remains a challenge. The authors reported on a small series of patients and provided a video presentation of a minimally invasive approach to L5 to S1 ELDHs utilizing a tubular retractor with microscopic visualization.

Dynamic Stabilization

Failed back surgery syndrome (FBSS) is reported to occur in 5 to 50% of cases of lumbar spine operation. A marked rise in the number of performed spinal procedures has also led to an increase in the number of FBSS cases, which is the consequence of biological, psychological, social, and/or economical causes. Patient selection and correct indications are of key importance for successful surgical intervention of this syndrome. Surgical interventions that have been used for FBSS treatment include decompression, stabilization and fusion, as well as dynamic stabilization/neutralization procedures (Chrobok et al, 2005).

Dynamic spinal stabilization devices are proposed as a way to provide immobilization and stabilization of spinal segments in skeletally mature individuals as an adjunct to fusion in the treatment of chronic instabilities or deformities of the thoracic, lumbar and sacral spine including, but not limited to, degenerative spondylolisthesis (with objective evidence of neurologic impairment) or previous failed spinal fusion. They are also cleared by the US Food and Drug Administration (FDA) for individuals who are receiving fusions with autogenous graft only, those who are having the device fixed or attached to the lumbar or sacral spine and those who are having the device removed after the development of a solid fusion mass.

These devices attach to the spine by way of titanium alloy screws that have been implanted into the spinal bone. Two screws are implanted per vertebra in two or three adjacent vertebrae. The protruding ends of the screws are attached to polyethylene-terephthalate cords. These cords are surrounded by a set of solid polycarbonate-urethane spacers. The system is designed to stabilize the spine by the polyethylene cords pulling against the spinal motions that separate the vertebrae. At the same time, the polycarbonate spacers push against the spinal motions that compress the vertebrae. These devices differ from traditional instrumentation used during spinal fusion, as they are non-rigid and allow some movement of the spine segments. Examples of dynamic spinal stabilization devices include, but may not be limited to, the Dynesys Stabilization System, the BAR Posterior Pedicle Screw System and the N Fix II Pedicle Screw System.

The use of rigid instrumentation in the treatment of degenerative spinal disorders seems to increase the fusion rate of the lumbar spine. However, rigid devices are associated with adverse effects such as pseudoarthrosis and adjacent segment degeneration. The use of semi-rigid and dynamic devices has been advocated to decrease such adverse effects of rigid fixation and thereby to attain a more physiological bony fusion (Korovessis et al, 2004). Dynamic stabilization systems (e.g., the Dynesys Spinal System) are intended to restrict segmental motion and thus prevent further degeneration of the lumbar spine. The Dynesys, a non-fusion pedicle screw stabilization system (a flexible posterior stabilization system), was developed in an attempt to overcome the inherent disadvantages of rigid instrumentation and fusion. It uses flexible materials threaded through pedicle screws rather than rigid rods or bone grafts alone as an adjunct to fusion. The Dynesys is installed posteriorly, and does not require bone to be taken from the hip, as is required in other fusion procedures. It is designed to prevent over-loading the disc, but it restricts extension and loses lordosis (Sengupta and Mulholland, 2005; Putzier et al, 2005).

The Dynesys Spinal System (Centerpulse Spine-Tech, Inc., Minneapolis, MN) was cleared by the FDA via a 510(k) pre-market notification in March 2004. According to the product labeling, it is indicated to provide stabilization of spinal segments in skeletally mature patients as an adjunct to fusion in the treatment of the chronic instabilities or deformities of the thoracic, lumbar and sacral spine: degenerative spondylolisthesis with objective evidence or neurological impairment, kyphosis; and failed previous fusion (pseudoarthrosis). In addition, the product labeling states that the Dynesys system is intended for use in persons who meet all of the following criteria:

Patients who are receiving fusions with autologous graft only; and
Patients who are having the device attached to the lumbar or sacral spine; and
Patients who are having the device removed after the development of a solid fusion mass.

The Dynesys Stabilization System has also been proposed for immobilization and stabilization of spinal segments without a spinal fusion procedure; at this time the FDA has not approved this application. Although the Dynesys has been in clinical use for several years, there is insufficient evidence demonstrating that implantation of this device results in improved health outcomes compared to standard treatments.

A more recent development has been a hybrid device, the Zimmer DTO Implant, which combines the Dynesys Dynamic Stabilization System with the rigid stabilization of the OPTIMA ZS Spinal System. This device is an attempt to offer a new segmental solution for treating degenerative lumbar spine pathologies with different stages of degeneration at contiguous levels.

Dynamic spinal stabilization devices may also be semi-rigid in design. These devices purportedly allow less spinal movement than the non-rigid, but more than traditional spinal fusion instrumentation. Examples of semi-rigid devices include the CD HorizoN Agile Dynamic Spinal Stabilization Device and the Isobar Spinal System.

In a RCT, Korovessis et al (2004) examined the short-term effects of rigid versus semi-rigid and dynamic instrumentation on the global and segmental lumbar spine profile, subjective evaluation of the result, and the associated complications. The study did not examine objective functional outcomes. They compared 3 equal groups of 45 adult patients, who underwent primary decompression and stabilization for symptomatic degenerative lumbar spinal stenosis. Patients were randomly selected and received either the rigid (Group A), or semi-rigid (Group B), or dynamic (Group C) spinal instrumentation with formal decompression and fusion. The mean ages for the 3 groups were 65 +/- 9, 59 +/- 16, and 62 +/- 10 years, respectively. All patients had detailed roentgenographical study including computed tomography (CT) scan and magnetic resonance imaging (MRI) before surgery to the latest follow-up observation. The following roentgenographical parameters were measured and compared in all spines: lumbar lordosis (L1 to S1), total lumbar lordosis (T12 to S1), sacral tilt, distal lordosis (L4 to S1), segmental lordosis, vertebral inclination, and disc index. The SF-36 health survey and visual analog scale (VAS) was used before surgery to the latest evaluation. All patients were evaluated after a mean follow-up of 47 +/- 14 months. Both lumbar and total lordosis correction did not correlate with the number of the levels instrumented in any group. Total lordosis was slightly decreased after surgery (3%, p < 0.05) in Group C. The segmental lordosis L2 to L3 was increased after surgery by 8.5% (p < 0.05) in Group C, whereas the segmental lordosis L4 to L5 was significantly decreased in Groups A and C by 9.8% (p = 0.01) and 16.2% (p < 0.01), respectively. The disc index L2 to L3 was decreased after surgery in Groups A and C by 17% (p < 0.05) and 23.5% (p < 0.05), respectively. The disc index L3 to L4 was increased in Group C by 18.74% (p < 0.01). After surgery, the disc index L4 to L5 was decreased in all 3 groups: Group A by 21% (p = 0.01), Group B by 13% (p < 0.05), and Group C by 13.23% (p < 0.05). The disc index L5 to S1 was significantly decreased in Group B by 13% (p < 0.05). The mean pre-operative scores of the SF-36 before surgery were 11, 14, and 13 for Groups C, B, and A, respectively. In the first year after surgery, there was a significant increase of the pre-operative SF-36 scores to 65, 61, and 61 for Groups C, B, and A, respectively, that represents an improvement of 83%, 77%, and 79%, respectively. In the second year after surgery and thereafter, there was a further increase of SF-36 scores of 19%, 23%, and 21% for Groups C, B, and A, respectively. The mean pre-operative scores of VAS for LBP for Groups C, B, and A were 5, 4.5, and 4.3, respectively, and decreased after surgery to 1.9, 1.5, and 1.6, respectively. The mean pre-operative scores of the VAS for leg pain for Groups C, B, and A were 7.6, 7.1, and 6.9, respectively, and decreased after surgery to 2.5, 2.5, and 2.7, respectively. All fusions healed radiologically within the expected time in all 3 groups without pseudoarthrosis or malunion. Delayed hardware failure (1 screw and 2 rod breakages) without radiological pseudoarthrosis was observed in 2 patients in Group C 1 year and 18 months following surgery. There was no adjacent segment degeneration in any spine until the last evaluation. These investigators concluded that all 3 instrumentations applied over a short area for symptomatic degenerative spinal stenosis almost equally maintained the pre-operative global and segmental sagittal profile of the lumbosacral spine and was followed by similarly significant improvement of both self-assessment and pain scores. Hardware failure occurred at a low rate following dynamic instrumentation solely without radiologically visible pseudoarthrosis or loss of correction. These researchers further noted that because of the similar clinical and radiological data in all 3 groups and the relative small number of patients that were included in each group, it is difficult to make any recommendation in favor of any instrumentation.

Putzier et al (2005) examined the effect of dynamic stabilization on the progression of segmental degeneration after nucleotomy. A total of 84 patients underwent nucleotomy of the lumbar spine for the treatment of symptomatic disc prolapse. Additional dynamic stabilization (the Dynesys system) was performed in 35 subjects. All patients showed signs of initial disc degeneration (Modic Type I – changes in the vertebral end plate are frequently associated with degenerative disc disease. Type 1 changes include decreased signal intensity on T1-weighted and increased signal intensity on T2-weighted MRI). Evaluation was carried out before surgery, 3 months after surgery, and at follow-up. The mean duration of follow-up was 34 months. Examinations included radiographs, MRI, physical examination, and subjective patient evaluation using Oswestry score and VAS. Clinical symptoms, Oswestry score, and VAS improved significantly in both groups after 3 months. At follow-up, a significant increase in the Oswestry score and in the VAS was seen only in the non-stabilized group. In the dynamically stabilized group, no progression of disc degeneration was noted at follow-up, while radiological signs of accelerated segmental degeneration existed in the solely nucleotomized group. There were no implant-associated complications. These investigators concluded that the Dynesys system is useful to prevent progression of initial degenerative disc disease of lumbar spinal segments following nucleotomy. Moreover, the same group of researchers noted that the Dynesys system seems not to be indicated for treating marked deformities or if osseous decompression needs to be performed (Putzier et al, 2004).

In contrast to the observation of Korovessis et al (2004) and Putzier et al (2005), a number of investigators have questioned whether the Dynesys Spinal System offers any clinical advantages over rigid instrumentation (Hopf et al, 2004; Grob et al, 2005; Schwarzenbach et al, 2005).

In a clinical trial, Hopf et al (2004) compared the use of artificial disc replacement with dynamic stabilization procedure (Dynesys’ method) in the treatment of patients with LBP. Indications for the operation were unsuccessful conservative treatment for over 6 months, segmental pain, age of less than 45 years, evidence of mono- or bi-segmental disc degeneration, with or without disc prolapse, demonstrated by MRI, exclusion of psychogenic disease and positive pre-operative, diagnostic measures such as facet joint infiltration and discography. These investigators stated that in younger patients with mono- or bi-segmental disc degeneration there is an indication for the implantation of an artificial disc. Contraindications for the operation are facet joint arthrosis and age of over 45 years. The investigators commented that the indication in subjects with a classic FBSS is still unclear, the improvement of the instrumentation and a further adaptation of the systems to the known biomechanics of the lumbar spine are mandatory as is an intensive discussion of the operative procedure in the case of revision operations. These authors further noted that the Dynesys’ method, with the inherent danger of segmental kyphozitation, a published, significant revision quota combined with a reduction of motility, does not fulfill this criterion.

back symptoms – 67% improved, 30% same, 3% worse;
leg symptoms – 64% improved, 21% same, 14% worse;
ability to do physical activities/sports – 40% improved, 33% same, 27% worse;
quality of life – 50% improved, 37% same, 13% worse;
how much the operation helped – 29% helped a lot, 23% helped, 10% only helped a little, 35% didn’t help, 3% made things worse.

These investigators concluded that their findings indicated that both back and leg pain are, on average, still moderately high 2 years following instrumentation with the Dynesys Spinal System. Only 50% of the patients declared that the operation had helped and had improved their overall quality of life; less than 50% reported improvements in functional capacity. The re-operation rate following implantation of the Dynesys was relatively high. The investigators concluded that these results provide no support for the notion that semi-rigid fixation of the lumbar spine resulted in better patient-oriented outcomes than those typical of fusion.

In a recent review on posterior dynamic stabilization systems, Schwarzenbach et al (2005) stated that their experience with the Dynesys has shown that this method has limitations in “elderly patients with osteoporotic bone or in patients with a severe segmental macro-instability combined with degenerative spondylolisthesis and advanced disc degeneration. Such cases have an increased risk of failure. Only future randomized evaluations will be able to address the potential reduction of accelerated adjacent segment degeneration. The few posterior dynamic stabilization systems that have had clinical applications so far have produced clinical outcomes comparable with fusion. No severe adverse events caused by these implants have been reported. Long-term follow-up data and controlled prospective randomized studies are not available for most of the cited implants but are essential to prove the safety, efficacy, appropriateness, and economic viability of these methods”.

In a review on dynamic stabilization in the surgical management of painful lumbar spinal disorders, Nockels (2005) concluded that posterior dynamic stabilization systems may provide benefit comparable to fusion techniques, but without the elimination of movement. Moreover, the author also noted that further study (well-designed prospective, randomized, controlled trial) is needed to ascertain optimal design and clinical indications.

In a systematic evidence review on non-rigid stabilization procedures for the treatment of LBP, the National Institute for Health and Clinical Excellence (NICE, 2005) stated that “current evidence on the safety of these procedures is unclear and involves a variety of different devices and outcome measures. Therefore, these procedures should not be used without special arrangements for consent and for audit or research”. Additionally, the specialist advisors to the Institute’s Interventional Procedures Advisory Committee noted that these procedures may be undertaken concurrently with disc decompression or discectomy. Thus, it is difficult to ascertain what clinical benefit is derived from the implants themselves. The specialist advisors noted that the reported adverse events include infection, malpositioned or broken screws leading to nerve root damage, cerebrospinal fluid leak, failure of the bone/implant interface, and failure to control pain. The theoretical risks with the techniques include: device failure (particularly long-term), increased lordosis, and root damage caused by loose or misaligned screws.

Welch and colleagues (2007) presented the preliminary clinical outcomes of dynamic stabilization with the Dynesys spinal system as part of a multi-center randomized prospective FDA investigational device exemption (IDE) clinical trial. This study included 101 patients from 6 IDE sites (no participants were omitted from the analysis) who underwent dynamic stabilization of the lumbar spine with the Dynesys construct. Patient participation was based on the presence of degenerative spondylolisthesis or retrolisthesis (Grade I), lateral or central spinal stenosis, and their physician’s determination that the patient required decompression and instrumented fusion for 1 or 2 contiguous spinal levels between L1 and S1. Subjects were evaluated pre-operatively, post-operatively at 3 weeks, and then at 3-, 6-, and 12-month intervals. The 100-mm VAS was used to score both lower-limb and back pain. Patient functioning was evaluated using the Oswestry Disability Index (ODI), and the participants’ general health was assessed using the Short Form-12 questionnaire. Overall, patient satisfaction was also reported. One hundred one patients (53 women and 48 men) with a mean age of 56.3 years (range of 27 to 79 years) were included. The mean pain and function scores improved significantly from the baseline to 12-month follow-up evaluation, as follows: leg pain improved from 80.3 to 25.5, back pain from 54 to 29.4, and ODI score from 55.6 to 26.3%. The authors concluded that the early clinical outcomes of treatment with Dynesys are promising, with lessening of pain and disability found at follow-up review. Dynesys may be preferable to fusion for surgical treatment of degenerative spondylolisthesis and stenosis because it decreases back and leg pain while avoiding the relatively greater tissue destruction and the morbidity of donor site problems encountered in fusion. However, long-term follow-up care is still recommended.

In a prospective case series, Kumar et al (2008) examined the radiological changes in the intervertebral disc after Dynesys dynamic stabilization. A total of 32 patients who underwent Dynesys procedure and have completed 2-year follow-up MRI scans were included in this study. Pre-operative and 2-year post-operative lumbar MRI scans were evaluated by 2 independent observers. T2-weighted mid-sagittal images were used and disc degeneration were classified according to the Woodend classification of disc degeneration. Anterior and posterior intervertebral disc heights were also measured. Of the 32 patients, 20 patients underwent Dynesys procedure alone and 12 underwent additional fusion at 1 or more levels. A total of 70 levels were operated on, of which 13 levels were fused. There was a statistically significant increase in the mean Woodend score at the operated levels in the Dynesys alone group, a change from 1.95 before surgery to 2.52 after surgery (p < 0.001). The mean Woodend scores changed from 1.27 pre-operative to 1.55 post-operative (p = 0.066) at the proximal adjacent levels, and from 1.37 to 1.62 at the distal levels (p = 0.157). There was good inter-observer agreement (weighted k score of 0.819). The anterior intervertebral disc height reduced by 2 mm from 9.25 to 7.17 (p < 0.001). The posterior disc height increased by 0.14 mm but this change insignificant. The authors concluded that disc degeneration at the bridged and adjacent segment seems to continue despite Dynesys dynamic stabilization.

The Stabilimax NZ Dynamic Spinal Stabilization System is an investigational device that is being evaluated for the treatment of patients with symptomatic spinal stenosis. The Stabilimax NZ is inserted and fixed to the vertebra by means of pedicle screws in exactly the same manner a fusion device is inserted and attached. The only difference is that for the Stabilimax NZ no bone graft will be placed around or between the vertebra to promote bone growth for fusion. It should be noted that a clinical trial sponsored by Applied Spine Technologies to evaluate if the Stabilimax NZ is at least as safe and effective as the control therapy of fusion in patients receiving decompression surgery for the treatment of clinically symptomatic spinal stenosis at 1 or 2 contiguous vertebral levels from L1 to S1 has been suspended (Applied Spine Technologies, 2008); the reason for this suspension is unclear.

Graf artificial ligament stabilization (Graf) is primarily used to stabilize the unstable vertebral segment without rigid fusion (Noorani and Topfer, 2006). The Graf technique involves insertion of pedicle screws into each vertebra to be stabilized which are then attached to one another with Dacron loops. This method has the theoretical advantages of simplicity (to surgeons familiar with the insertion of pedicle screws), avoidance of bone graft donor site problems, and allowing a spinal fusion to be attempted at a later date if considered necessary (Noorani and Topfer, 2006). The concept of ligament stabilization was introduced by H. Graf in the early 1990s and performed in patients with chronic back pain as a less invasive technique than spinal or posterio-lateral fusion.

In a retrospective, long-term, follow-up study, Kanayama et al (2007) reported minimum 10-year follow-up results of posterior dynamic stabilization using Graf artificial ligament (Graf ligamentoplasty) and evaluated the role and limitations of this procedure in the treatment of degenerative lumbar disorders. A total of 56 consecutive patients who underwent Graf ligamentoplasty were reviewed at a minimum 10-year follow-up. Forty-three patients in the original cohort had sufficient clinical and radiographical follow-up for analysis. The pathologies included degenerative spondylolisthesis in 23 patients, disc herniation with flexion instability in 13 patients, spinal stenosis with flexion instability in 4 patients, and degenerative scoliosis in 3 patients. Single-level procedures were performed in 36 patients; multi-level procedures were performed in 7 patients. Radiographical and clinical assessments were performed before surgery and at the final follow-up. Disability due to LBP and/or sciatic symptoms was significantly improved in the patients with degenerative spondylolisthesis or flexion instability. However, degenerative scoliosis and/or laterolisthesis were associated with poor clinical improvement. In radiographical assessment, segmental lordosis was maintained in 10.9 degrees, and flexion-extension motion was averaged 3.6 degrees at the final follow-up. Facet arthrodesis eventually occurred in 14 patients (32.6%) at an average of 82 months after surgery. Additional surgeries were required in 3 patients (7.0%) for adjacent segment pathologies. The authors concluded that long-term results showed that Graf ligamentoplasty is an effective treatment option for low-grade degenerative spondylolisthesis and flexion instability. However, this procedure has limitations to correct spinal deformity, and is not advocated for the treatment of degenerative scoliosis and laterolisthesis.

In a discussion of the afore-mentioned study, Fraser (2007) stated that “[p]erhaps the main value of this retrospective study is the finding that Graf ligamentoplasty is not effective in the treatment of patients with degenerative scoliosis, but the long-term efficacy of the Graf procedure for other lumbar conditions is yet to be proven”.

Putzier et al (2010) compared dynamic fixation of a clinically asymptomatic initially degenerated segment adjacent to fusion (iASD), with circumferential lumbar fusion alone. A total of 60 patients with symptomatic degeneration of L5/S1 or L4/L5 (Modic greater than or equal to 2 degrees) and asymptomatic iASD (Modic = 1 degrees, confirmed by discography) were divided into 2 groups; 30 patients were treated with circumferential single-level fusion (SLF). In dynamic fixation transition (DFT) patients, additional posterior dynamic fixation of iASD was performed. Pre-operatively, at 12 months, and at a mean follow-up of 76.4 (60 to 91) months, radiological (MRI, X-ray) and clinical (ODI, VAS, satisfaction) evaluations assessed fusion, progression of adjacent segment degeneration (PASD), radiologically adverse events, functional outcome, and pain. At final follow-up, 2 non-fusions were observed in both groups. A total of 6 SLF patients and 1 DFT patient presented a PASD. In 2 DFT patients, a PASD occurred in the segment superior to the dynamic fixation, and in 1 DFT patient, a fusion of the dynamically fixated segment was observed. A total of 4 DFT patients presented radiological implant failure. While no differences in clinical scores were observed between groups, improvement from pre-operative conditions was significant (all p < 0.001). Clinical scores were equal in patients with PASD and/or radiologically adverse events. The authors do not recommend dynamically fixating the adjacent segment in patients with clinically asymptomatic iASD. The lower number of PASD with dynamic fixation was accompanied by a high number of implant failures and a shift of PASD to the superior segment.

In summary, despite some preliminary evidence that dynamic stabilization systems (e.g., the Dynesys) have produced clinical outcomes comparable to that of fusion, the clinical value of dynamic stabilization awaits the findings of prospective, RCTs, which are an essential requirement for practice of evidence-based medicine.

Inter-Spinous Distraction and Interlaminar Stabilization Procedures

Lumbar spinal stenosis (LSS) refers to narrowing of the lumbar spinal canal, lateral recess, or foramen resulting in neurovascular compression that may lead to pain. Spinal stenosis may be classified by etiology (e.g., congenital or acquired) or symptomatology (e.g., radiculopathy, neurogenic claudication, or mechanical back pain). It can also be classified radiographically, by the location of the stenosis (e.g., central canal, lateral recess, or intervertebral foramen) or by the presence of deformity such as spondylolisthesis or scoliosis. Overlapping in the classification of LSS can occur in that central stenosis with thecal sac compression usually leads to neurogenic claudication, while lateral recess compression is associated with compression of an individual nerve root, thus resulting in radiculopathy. Although symptoms may arise from narrowing of the spinal canal, not all patients with narrowing develop symptoms. The reason why some patients develop symptomatic stenosis and others do not is still unknown. Therefore, LSS does not refer to the pathoanatomical finding of spinal canal narrowing. It is a clinical syndrome of lower extremity pain caused by mechanical compression on neural elements or their vascular supply (Truumees, 2005).

Non-surgical treatments (e.g., activity modification, medications such as NSAIDs, physical therapy that focuses on flexion-based exercises, as well as epidural steroid injections) are usually the first treatment choice for patients suffering from neurogenic intermittent claudication (NIC) secondary to LSS. If symptoms failed to improve with non-surgical treatments, decompressive surgery (e.g., laminectomy, facetectomy, multi-level laminotomies, fenestration, distraction laminoplasty, and microscopic decompression), with or without fusion, may be necessary. Moreover, several studies reported that surgical treatment produces better outcomes than non-surgical treatment in the short-term; however, the results tend to deteriorate with time (Yuan et al, 2005).

While fusion operations have traditionally been used to manage many disorders of the lumbar spine related to instability, pain, or deformity, concern over the long-term effects of fusion on adjacent spinal segments has led to the development of new approaches such as inter-spinous distraction procedures.

Examples of US Food and Drug Administration (FDA) approved interspinous process spacers include, but may not be limited to, the Superion Interspinous Spacer, the X-Stop Interspinous Process Decompression (IPD) System and the X-Stop PEEK IPD System.

Interspinous process decompression is a minimally invasive surgical procedure that is proposed to relieve the symptoms of lumbar spinal stenosis in those patients who do not respond to conservative, nonsurgical treatment. The procedure involves implanting interspinous process decompression spacers between the spinous processes of the vertebrae which appear to be the source of the symptoms. The spacers can be implanted at one or two lumbar levels and are designed to remain in place without being permanently affixed to the bone or ligamentous structures of the spine.

the universal wing, and
the main body (with oval spacer and tissue expander).

The wings prevent anterior and lateral movement while the supraspinous ligament prevents posterior displacement. The oval spacer swivels, making it self-aligning relative to the uneven surface of the spinous process. This ensures that no sharp edges come into contact with the spinous process and that compressive loads are distributed equally on the surface of the bone.

The X-Stop Inter-Spinous Process Distraction/Decompression System gained FDA’s PMA in November 2005 for use in alleviating the symptoms of patients with LSS. The X-Stop is intended to be used in patients with symptomatic LSS at 1 or 2 levels who have failed at least 6 months of conservative treatment. Under local anesthesia, the implant is inserted between the spinous processes of the affected level(s), and prevents extension at those levels. Talwar et al (2005) stated that patients with lower bone mineral density must be approached with more caution during insertion of the inter-spinous process implant.

According to SFMT Europe B.V., a subsidiary of St. Francis Medical Technologies, the X-Stop is indicated for any of the following conditions:

Axial-load induced back pain; or
Baastrup’s syndrome (also known as kissing spines); or
Contained herniated nucleus pulposus; or
Degenerative and/or iatrogenic (post-discectomy) disc syndrome; or
Facet syndrome; or
Neurogenic intermittent claudication due to central and/or lateral-recess LSS; or
Spondylolisthesis up to grade 1.5 (of 4) (about 35%), with NIC; or
Unloading of disc adjacent to a lumbar fusion procedure, primary or secondary.

There is a scarcity of randomized controlled studies on the clinical value of the X-Stop for the indications listed above, especially its long-term (over 2 years) benefits. Currently, available evidence on this device is mainly from J.F. Zucherman and K.Y. Hsu (developers of this technology), and their associates.

Verhoof and colleagues (2008) stated that the X-Stop inter-spinous distraction device has been reported to be an alternative to conventional surgical procedures in the treatment of symptomatic degenerative lumbar spinal stenosis. However, the effectiveness of the X-Stop in symptomatic degenerative lumbar spinal stenosis caused by degenerative spondylolisthesis is not known. A cohort of 12 consecutive patients with symptomatic lumbar spinal stenosis caused by degenerative spondylolisthesis were treated with the X-Stop inter-spinous distraction device. All patients had LBP, neurogenic claudication and radiculopathy. Pre-operative radiographs revealed an average slip of 19.6%. Magnetic resonance imaging of the lumbo-sacral spine showed a severe stenosis. In 10 patients, the X-Stop was placed at the L4 to L5 level, whereas 2 patients were treated at both, L3 to L4 and L4 to L5 level. The mean follow-up was 30.3 months. In 8 patients, a complete relief of symptoms was observed post-operatively, whereas the remaining 4 patients experienced no relief of symptoms. Recurrence of pain, neurogenic claudication, and worsening of neurological symptoms was observed in 3 patients within 24 months. Post-operative radiographs and MRI did not show any changes in the percentage of slip or spinal dimensions. Finally, secondary surgical treatment by decompression with postero-lateral fusion was performed in 7 patients (58%) within 24 months. The authors concluded that the X-Stop inter-spinous distraction device showed an extremely high failure rate, defined as surgical re-intervention, after short term follow-up in patients with spinal stenosis caused by degenerative spondylolisthesis. They do not recommend the X-Stop for the treatment of spinal stenosis complicating degenerative spondylolisthesis.

Lindsey et al (2003) examined the kinematics of the instrumented lumbar spine and adjacent levels due to the insertion of the X-Stop. Seven lumbar spines (L2 to L5) were tested in flexion-extension, lateral bending, and axial rotation. Images were taken during each test to determine the kinematics of each motion segment. The X-Stop was inserted at the L3 to L4 level, and the test protocol was repeated. These researchers found that the X-Stop does not significantly alter the kinematics of the motion segments adjacent to the instrumented level.

In a study using 7 cadaveric spines (L2 to L5), Fuchs et al (2005) noted that the X-Stop may be used in conjunction with a unilateral medial facetectomy or unilateral total facetectomy. However, it should not be used in conjunction with bilateral total facetectomy. In another cadaveric L2 to L5 spine study (n = 7), Wiseman et al (2005) reported that inter-spinous process decompression by placing the X-Stop between the L3 to L4 spinous processes will unlikely cause adjacent level facet pain or accelerated facet joint degeneration. Furthermore, pain induced from pressure originating in the facets and/or posterior anulus of the lumbar spine may be relieved by inter-spinous process decompression. Richards et al (2005) quantified the effect of the X-Stop on the dimensions of the spinal canal and neural foramina during flexion and extension. By means of a positioning frame, 8 specimens (L2 to L5) were positioned to 15 degrees of flexion and 15 degrees of extension. Each specimen was assessed using magnetic resonance imaging (MRI), with and without the X-Stop, placed between the L3 to L4 spinous processes. Canal and foramina dimensions were compared between the intact and implanted specimens. These investigators concluded that the X-Stop prevents narrowing of the spinal canal and foramina in extension.

Lee and colleagues (2004) reported their preliminary findings on the use of the X-Stop for LSS in elderly patients (n = 10). Subjects were evaluated post-operatively by MRI and the Swiss Spinal Stenosis Questionnaire. Cross-sectional areas of the dural sac and intervertebral foramina at the stenotic level were measured post-operatively and compared with the pre-operative values. After implantation of the X-Stop, the cross-sectional area of the dural sac increased 16.6 mm2 (22.3%) and intervertebral foramina increased 22 mm2 (36.5%). The intervertebral angle as well as the posterior disc height changed significantly. A total of 70% of the patients stated that they were satisfied with the surgical outcome.

In a multi-center, prospective, randomized, controlled trial, Zucherman and colleagues (2005) compared the outcomes of X-Stop treated NIC patients (n = 100) with their non-operatively treated counterparts (n = 91). The primary outcomes measure was the Zurich Claudication Questionnaire (ZCQ) – a patient-completed, validated instrument for NIC. At every follow-up visit, X-Stop treated patients had significantly better outcomes in each domain of the ZCQ. At 2 years, the X-Stop treated patients improved by 45.4% over the mean baseline Symptom Severity score compared with 7.4% in the control group; the mean improvement in the Physical Function domain was 44.3% in the X-Stop group and -0.4% in the control group. In the X-Stop group, 73.1% patients were satisfied with their treatment compared with 35.9% of control patients.

Siddiqui et al (2007) reported on the one year results of a prospective observational study of the X Stop interspinous implant for the treatment of lumbar spinal stenosis. Forty consecutive patients were enrolled and surgically treated with X Stop implantation. The X Stop device was implanted at the stenotic segment, which was either at 1 or 2 levels in each patient. Sixteen of 40 patients failed to complete all clinical questionnaires at each of the specified time intervals and were excluded from the study. The investigators reported that, by 12 months after surgery, 54% of the 24 remaining patients reported clinically significant improvement in their symptoms, 33 reported clinically significant improvement in their physical function, and 71% expressed satisfaction with the procedure. Twenty-nine percent of patients required caudal epidural after 12 months for recurrence of their symptoms of neurogenic claudication. The investigators noted that, although this study indicates that the X Stop offers significant short-term improvement, these results were less favorable than the previous randomized clinical study. Limitations of this study include the lack of a control group, short duration of follow-up, and high proportion of dropouts.

In a literature review, Christie et al (2005) evaluated the mechanisms of action and effectiveness of inter-spinous distraction devices in managing symptomatic lumbar spinal pathology. They stated that these devices continue to be evaluated in clinical trials; and that although the use of inter-spinous implants is still experimental, the early results are promising, and it is likely that future studies will establish a niche for them in the management of lumbar spinal pathology.

Bono and Vaccaro (2007) reviewed interspinous process devices for the lumbar spine, and stated that, although some clinical data exist for some of these devices, defining the indications for these minimally invasive procedures will be crucial. “Indications should emerge from thoughtful consideration of data from randomized controlled studies”.

Based upon a systematic evidence review on inter-spinous distraction procedures for spinal stenosis causing neurogenic claudication in the lumbar spine, the National Institute for Health and Clinical Excellence (NICE, 2006) concluded that “evidence of efficacy is limited and is confined to the medium and short term. These procedures should only be used in the context of special arrangements for consent, audit and research”. Additionally, the specialist advisors to the Institute’s Interventional Procedures Advisory Committee noted that given the fluctuating symptoms associated with this condition, the assessment of outcomes in clinical studies may be unreliable. Furthermore, some advisors questioned the long-term effectiveness of the procedure.

The questions regarding the long-term effectiveness of the X-Stop raised by Christie et al (2005) as well as some specialist advisors of the National Institute for Health and Clinical Excellence’s Interventional Procedures Advisory Committee (2006) are congruous with those raised by documents released by the FDA in 2004 prior to a public hearing on the product. The FDA’s PMA review stated that “although the device can be inserted with a minimally invasive operative technique as an outpatient procedure with generally a local anesthetic a decision as to the safety and effectiveness of this device is based solely on 24 month data because information on the patient outcomes after 24 months is not available. This information becomes important when looking at pain relief and return to function. Even though the goal of the study was accomplished showing a significant, statistical difference between the investigational and control groups, more patients report improvement at 12 months than at 24 months. Contrary to what has been observed in spinal fusion studies, in this study, a percentage of patients whose symptoms improved at 6 and 12 months show a trend of regression of pain and function symptoms toward baseline levels. There appears to be a trend with early pain relief but the data suggests that in about 15% of patients initially successfully treated by the X-stop had only temporary relief”.

On August 31, 2004, the FDA’s Orthopaedic and Rehabilitation Devices Panel voted 5 to 3 to recommend a “not approvable” decision on the PMA for the X-Stop. The Panel cited concern with the need to identify the patient population that is most likely to benefit from the device, noting that overall effectiveness was not demonstrated in a majority of the clinical study population. The Panel also cited concerns with the longer term effectiveness of the device (longer than 2 years), with potential bias in the clinical study, and with the need for radiographic or other objective evidence of the device’s mechanism of effect on the spine in patients.

As a condition of approval, the FDA has required the manufacturer to conduct a post-marketing study of the long-term safety and effectiveness of the X-Stop in patients who received the X-Stop under the Investigational Device Exemption (IDE). The FDA has required the manufacturer to conduct an additional post-approval study involving 240 patients at up to 8 clinical sites.

Guidelines from the North American Spine Society (NASS, 2007) concluded that there was insufficient evidence to support the use of the XSTOP in persons with lumbar spinal stenosis. The NASS guidelines noted: “Although the study cited in support of this recommendation is a level I study, it is a single study. Therefore, until further evidence is published there remains insufficient evidence to make a recommendation [about the use of the XSTOP in lumbar spinal stenosis]”. More recently, guidelines from the North American Spine Society (NASS, 2011) concluded: “there is insufficient evidence at this time to make a recommendation for or against the placement of an interspinous process spacing device in patients with lumbar spinal stenosis.”

In summary, the clinical value of X-Stop for patients with LSS is still uncertain. In particular, whether its reported benefit will decline over time will require more research with longer-term evaluation. Additionally, further randomized controlled studies are needed to compare these inter-spinous process implants with traditional surgical interventions such as laminectomy and/or fusion.

In December 2004, the FDA granted 510(k) approval for ExtenSure bone allograft inter-spinous spacer device, which is a cylindrically fashioned piece of allograft bone intended to effect distraction, restore and maintain the space between 2 adjacent spinous processes and indirectly decompress a stenotic spinal canal at 1 or 2 levels. The procedure promotes fusion of the allograft to the spinous process above, while allowing motion between the allograft and the spinous process below. It is thought that this would provide a long-term solution to implant stability while retaining segmental motion. It may also be used to facilitate fusion between 2 or more adjacent spinous processes. This is similar to the action of the X-Stop device. However, there is a lack of clinical studies demonstrating effectiveness of the ExtenSure device.

The Total Posterior Spine (TOPS) System

The TOPS System, a total posterior arthroplasty implant, is an alternative to spinal fusion that is designed to stabilize but not fuse the affected vertebral level following decompression surgery to alleviate pain stemming from lumbar spinal stenosis while maintaining range of motion. It is indicated for patients with lower back and leg pain resulting from moderate-to-severe lumbar spinal stenosis at a single level between L3 and L5 that may be accompanied by facet arthrosis or degenerative spondylolisthesis. The TOPS System is not available for commercial use in the United States. Enrollment for an FDA investigational device exemption study commenced in May 2008.

Wilke et al (2006) noted that the total posterior spine (TOPS) System is designed to replace the posterior elements of a functional spinal unit, to provide flexible re-stabilization and spinal alignment, while maintaining the intervertebral disc. The implant is composed of bilateral pedicle screws, connected with 2 cross-bars in the transversal plane. The cross-bars are joined together by an elastic element capable of transmitting tensile and compressive loads, as well as shear forces. In an in-vitro study, these researchers characterized the flexibility of a new total posterior-element system when instrumented to the L4- to L5 segments. These investigators examined if an optimized version of the TOPS implant (Impliant Ltd., Ramat Poleg, Israel) is capable to restore the physiologic motion characteristic of a spinal segment following facetectomy. A total of 6 human cadaver specimens (L3 to S1) (median age of 61 years: minimum of 47 years, and maximum of 74 years) were used for this in-vitro study. The specimens were loaded with pure moments of +/- 7.5 Nm in flexion/extension, lateral bending, and axial rotation. The following states were investigated: intact; after bilateral laminectomy, including facetectomy of the lower facet joints, of the upper vertebra L4; and after device implantation. The ROM, neutral zone, and intra-discal pressure were determined from a third cycle. In a 2nd step, the ROM in axial rotation was determined as a function of different flexion/extension postures. In the neutral position, the laminectomy and facetectomy increased the median values of the ROM in flexion plus extension, lateral bending right plus left, and significantly in axial rotation left plus right from: 8.2 degrees, 7.6 degrees, 3.6 degrees to 12.1 degrees, 8.5 degrees, and 8.5 degrees (Wilcoxon signed rank test; p < 0.05). After fixation of the implant, the ROM was again reduced to 6.8 degrees, 7.8 degrees, and 3.8 degrees. In a flexed posture, the ROM in axial rotation was slightly increased compared to the neutral position. With increasing extension, the axial rotation decreased linearly from 3.7 degrees in neutral position to 2.3 degrees in 4 degrees extension in the segment L4 to L5. The characteristic of the intra-discal pressure versus load with the implant was similar to that of the intact specimen. The authors concluded that the TOPS implant almost ideally restored the ROM in lateral bending and axial rotation compared to that of the intact specimen. In the sagittal plane, 85 % of the intact ROM could be obtained. The ROM in axial rotation as a function of flexion and extension angle also mimicked the biomechanical behavior of the posterior complex of a lumbar spine. This relationship between ROM and posture emphasized the importance of a proper implantation.

McAfee et al (2007) stated that total disc replacement is an alternative to lumbar fusion; however, patients with spinal stenosis, spondylolisthesis, and facet arthropathy are often excluded from this procedure because increased adjacent-segment motion could exacerbate dorsal spondylotic changes. In such cases of degenerative spondylolisthesis with stenosis, decompression and fusion remain the gold standard of treatment. To avoid attendant loss of motion at the treated segment, the TOPS system is a novel total posterior arthroplasty prosthesis that allows for an alternative dynamic, multi-axial, 3-column stabilization, and motion preservation. These investigators reported preliminary surgical data and clinical outcomes in patients treated with the TOPS lumbar total posterior arthroplasty system. A total of 29 patients were enrolled in a prospective, non-randomized, multi-center, pilot study. All subjects had spinal stenosis and/or spondylolisthesis at L4 to L5 due to facet arthropathy. Radiographs and scores on outcome measures including the VAS for pain, ODI, Short Form-36, and Zurich Claudication Questionnaire (ZCQ) were prospectively recorded before surgery and at 6-week, 3-month, 6-month, and 1-year intervals after surgery. Before instrumentation, a bilateral total facetectomy and laminectomy at L4 to L5 or L3 to L4 was carried out through a standard mid-line posterior approach. Following decompression, the TOPS screws were inserted into 4 pedicles to achieve maximal purchase with triangulating bicortical trajectories. An appropriately sized TOPS arthroplasty implant was then applied. The mean surgical time was 3.1 hours, and patients’ clinical status improved significantly following treatment with the TOPS device. The mean ODI score decreased compared with baseline by 41 % at 1 year, and the 100-mm VAS score declined by 76 mm over the same time period. Radiographic analysis showed that lumbar motion was maintained, disc height was preserved, and no evidence of screw loosening was found. No device malfunctions or migrations and no device-related AEs were reported during the study. The authors concluded that although long-term, comparative data are needed, it was clear from these preliminary findings that the TOPS total posterior arthroplasty device was a safe and effective alternative to fusion for patients who suffer from moderate-to-severe lumbar spinal stenosis. Clinical outcomes demonstrated significant improvement in ODI, VAS, and ZCQ scores at all intervals, as late as preliminary follow up at 1 year. No device-related AEs were reported, and all AEs that were unrelated to the device were consistent with published rates. These researchers stated that these promising preliminary findings warrant further investigation via the recently initiated, prospective, randomized, multi-center FDA pivotal TOPS Trial.

Meyers et al (2008) noted that dynamic stabilization is an alternative to fusion intended to eliminate or at least minimize the potential for adjacent level degeneration. Different design approaches are used in pedicle screw-based systems that should have very different effects on the loading of the posterior column and intervertebral disc. If the implant system distributes these loads more evenly, loads in the pedicle screws will be reduced, and screw loosening will be prevented. In a controlled laboratory study, these researchers determined how 2 different design approaches to dynamic stabilization systems, the Dynesys System, and the TOPS System, would affect the load carried by the pedicle screws. They examined the magnitude of the motions on pedicle screws during flexion-extension and lateral bending were measured after implantation of 2 posterior dynamic stabilization devices into cadaveric spines. A total of 5 lumbar spines were tested in flexion-extension and lateral bending. Specimens were tested sequentially: first intact, then with the Dynesys System implanted, and finally with the TOPS System implanted; ROM for each construct was measured with a 210N and 630N compressive load. The pedicle screws were instrumented with strain gages, which were calibrated so that the motions on the screws could be determined from the strain measurements. Compared with intact values, ROM decreased in flexion-extension and lateral bending when the Dynesys System was implanted. With implantation of the TOPS System, ROM returned to values that were not significantly different from the intact values. The motions in the screws with the Dynesys System were significantly higher than with the TOPS System with increases of as much as 56 % in flexion-extension and 86 % in lateral bending. The authors concluded that the findings of this study showed a marked interaction between the type and amount of constraint provided by the device and subsequent load sharing with the spine. These researchers stated that using instrumented screws could provide valuable pre-clinical data for correlation with subsequent clinical findings.

The authors stated that this study had several drawbacks. First, the small number of specimens (n = 5). These investigators had adequate power to show significant differences between their primary variable, implant design; however, some of the other relations they examined approached, but failed to reach significance. Second, the number of levels used for each specimen was also limited. Specimens extending from L3 to S1 were plotted; however, only L4 to L5 was instrumented. This was necessary to allow room for the hardware being tested, but of course the extra levels meant that larger ROMs were recorded than probably would have occurred if only a single spinal unit had been tested. Because a direct comparison was made with both implants in the same specimen, however, this should not have affected their conclusions. Third, the non-randomized order of testing. These researchers carried out the comparison between designs within the same spine, necessitating that the TOPS System be tested last because implantation required removal of bone. A limitation in the testing modes was that specimens were not tested in axial rotation. This was because of experimental limitations in their measuring equipment. Fourth, these researchers measured the motions in the screws in only 1 plane. The total resultant motion acting on the screw may be larger. Placing strain gages on more than 1 plane of the screw would be arduous; the authors felt it most important to measure the movement in the primary plane of motion. They stated that the clinical relevance of their motion measurements in the pedicle screws was unknown, because they did not know what level of screw load is needed for loosening; 10 % of patients treated with the Dynesys System suffered screw loosening in a study by Stoll et al (2002), but whether the lower loads found with the TOPS System would relate to a lower incidence of loosening must await clinical experience with this system.

In a review of the evidence on surgery for LBP for the American Pain Society’s clinical practice guideline, Chou et al (2009) concluded that surgery for radiculopathy with herniated lumbar disc and symptomatic spinal stenosis is associated with short-term benefits compared to non-surgical therapy, though benefits diminish with long-term follow-up in some trials. For non-radicular back pain with common degenerative changes, fusion is no more effective than intensive rehabilitation, but associated with small -to-moderate benefits compared to standard non-surgical therapy. Moreover, they stated that although there is fair evidence that an inter-spinous spacer device is moderately more effective than non-surgical therapy for 1- or 2-level spinous stenosis, there are insufficient data to evaluate long-term benefits and harms.

In a prospective, non-randomized, clinical study, Anekstein et al (2015) examined the feasibility and clinical improvement of a total posterior arthroplasty system in the surgical management of lumbar degenerative spondylolisthesis and/or spinal stenosis. A total of 10 patients were enrolled in this trial. The primary indication was neurogenic claudication due to spinal stenosis with single-level degenerative spondylolisthesis. Patients were evaluated with X-rays and MRI scans, VAS for back and leg pain, the ODI, and the SF-36 health survey pre-operatively, at 6 weeks, 3 months, 6 months, and at 1, 2, 3 and 7 years post-operatively. The VAS score for back pain decreased from 56.2 pre-operatively to 12.5 at 6 weeks, and 19 at 7 years follow-up. The VAS score for worse leg pain decreased from 83.5 before surgery to 13 at 6 weeks, and 8.8 at 7 years follow-up. The ODI was lowered from 49.1 pre-operatively to 13.5 at 6 weeks, and 7.8 at 7 years follow-up. MRI examination at 7 years after surgery did not reveal stenosis adjacent to the stabilized segment. Spondylolisthesis did not progress in any of the cases. One patient had a symptomatic L3 to L4 far-lateral disc herniation 5 years after surgery whose symptoms resolved with non-operative treatment. In 1 patient, conversion to posterolateral fusion was carried out due to an early device malfunction. The authors concluded that the findings of this long-term study were encouraging. In patients with spinal stenosis and degenerative spondylolisthesis, decompression and posterior arthroplasty with the TOPS System could maintain clinical improvement and radiologic stability over time. The TOPS System preserved motion at the instrumented level and may prevent degeneration at adjacent motion segments. Moreover, these researchers stated that drawbacks of this trial included the small number of patients (n = 10); and the fact that it was not a comparative study.

Fiani et al (2020) stated that degenerative disease of the lumbar spine commonly develops with age and can cause debilitating pain or neurologic deficits. When minimally invasive treatments and pain management interventions fail to provide relief, the traditional treatment has consisted of decompression surgery followed by the possible need for lumbar fusion. A mechanical implant device, known as the TOPS System, has been introduced as a potential dynamic alternative to fusion surgery following decompression. The device is a dynamic posterior arthroplasty via pedicle screw insertion that maintains mobility, flexibility, and ROM by providing multiaxial, 3-column stabilization. These investigators noted that while currently approved for use in Europe, the device is undergoing clinical trials in the U.S. to ascertain its effectiveness and potential complications. The authors provided a review of the literature that identified both positive results and adverse effects. These researchers stated that while TOPS’ use demonstrated excellent potential, additional prospective studies are needed to determine this system’s long-term complications. Furthermore, they stated that additional investigations should aim to develop, in greater detail, the possible causes of adverse effects based on patient history to identify additional contraindications.

The Coflex (Paradigm Spine) is an interlaminar spinal stabilization device for persons with lumbar stenosis that is implanted following laminectomy and decompression. The device is intended to provide benefits over fusion, including durable pain relief, maintenance of spinal motion, reduced hypermobility of adjancent segments resulting in reduced degeneration at adjacent levels. A pivotal randomized controlled clinical trial evaluated the noninferiority of the Coflex interlaminar stabilization with instrumented posterolateral spinal fusion (pedicle screw fixation) in subjects with back pain and spinal stenosis and no or mild instability (up to grade 1 spondylolisthesis) who had failed conservative management. The primary outcome of the study is improvements in Oswestry Disability Index (ODI) score, and secondary outcomes include the Visual Analog Scale (VAS) back and leg pain, and the Zurich Claudication Questionnaire (ZCQ) score. Other endpoints measured include range of motion at the level adjacent to the procedure, as range of motion has been found to be related to the development of adjacent level degeneration and disease. Subjects were followed over a two-year period. Limitations of the study include the lack of blinding and the intermediate duration of the study. In addition, the study compared the effectiveness of the Coflex device with spinal fusion in spinal stenosis subjects with no instability; however, the benefits of spinal fusion this group of patients is uncertain.

In a prospective, randomized, multi-center, FDA IDE trial, Davis et al (2013a) evaluated the safety and effectiveness of Coflex interlaminar stabilization compared with posterior spinal fusion (PSF) in the treatment of 1- and 2-level spinal stenosis and degenerative spondylolisthesis. A total of 322 patients (215 Coflex and 107 fusions) from 21 sites in the U.S. were enrolled between 2006 and 2010. Subjects were randomized to receive laminectomy and Coflex interlaminar stabilization or laminectomy and postero-lateral spinal fusion with spinal instrumentation in a 2:1 ratio. Overall device success required a 15-point reduction in ODI, no re-operations, no major device-related complications, and no post-operative epidural injections. Patient follow-up at minimum 2 years was 95.3% and 97.2% in the Coflex and fusion control groups, respectively. Patients taking Coflex experienced significantly shorter operative times (p < 0.0001), blood loss (p < 0.0001), and length of stay (p < 0.0001). There was a trend toward greater improvement in mean ODI scores in the Coflex cohort (p = 0.075). Both groups demonstrated significant improvement from baseline in all VAS back and leg parameters. Patients taking Coflex experienced greater improvement in Short-Form 12 physical health outcomes (p = 0.050) and equivalent mental health outcomes. Coflex subjects experienced significant improvement in all ZCQ outcomes measures compared with fusion (symptom severity [p = 0.023]; physical function [p = 0.008]; satisfaction [p = 0.006]). Based on the FDA composite for overall success, 66.2% of Coflex and 57.7% of fusions succeeded (p = 0.999), thus demonstrating non-inferiority. The overall adverse event rate was similar between the groups, but Coflex had a higher re-operation rate (10.7% versus 7.5%, p = 0.426). At 2 years, fusions exhibited increased angulation (p = 0.002) and a trend toward increased translation (p = 0.083) at the superior adjacent level, whereas Coflex maintained normal operative and adjacent level motion. The authors concluded that Coflex interlaminar stabilization is a safe and effective alternative, with certain advantages compared with lumbar spinal fusion in the treatment of spinal stenosis and low-grade spondylolisthesis.

In a prospective, randomized, multi-center FDA IDE trial, Davis et al (2013b) evaluated the safety and effectiveness of Coflex Interlaminar Stabilization compared with PSF to treat low-grade spondylolisthesis with spinal stenosis. A total of 322 patients from 21 sites in the U.S. were enrolled between 2006 and 2008 for the IDE trial. The current study evaluated only the subset of patients from this overall cohort with Grade 1 spondylolisthesis (99 in the Coflex group and 51 in the fusion group). Subjects were randomized 2:1 to receive decompression and Coflex interlaminar stabilization or decompression and PSF with spinal instrumentation. Data collected included peri-operative outcomes, ODI, back and worse leg VAS scores, 12-Item Short Form Health Survey, ZCQ, and radiographic outcomes at a minimum of 2 years. The FDA criteria for overall device success required the following to be met: 15-point reduction in ODI, no re-operations, no major device-related complications, and no post-operative epidural injections. At a minimum of 2 years, patient follow-up was 94.9% and 94.1% in the Coflex and fusion control groups, respectively. There were no group differences at baseline for any demographic, clinical, or radiographic parameter. The average age was 63 years in the Coflex cohort and 65 years in the fusion cohort. Coflex subjects experienced significantly shorter operative times (p < 0.0001), less estimated blood loss (p < 0.0001), and shorter length of stay (p < 0.0001) than fusion controls. Both groups experienced significant improvements from baseline at 2 years in ODI, VAS back, VAS leg, and ZCQ, with no significant group differences, with the exception of significantly greater ZCQ satisfaction with Coflex at 2 years. The FDA overall success was achieved in 62.8% of Coflex subjects (59 of 94) and 62.5% of fusion controls (30 of 48) (p = 1.000). The re-operation rate was higher in the Coflex cohort (14 [14.1%] of 99) compared with fusion (3 [5.9%] of 51, p = 0.18), although this difference was not statistically significant. Fusion was associated with significantly greater angulation and translation at the superior and inferior adjacent levels compared with baseline, while Coflex showed no significant radiographic changes at the operative or index levels. The authors concluded that low-grade spondylolisthesis was effectively stabilized by Coflex and led to similar clinical outcomes, with improved per-operative outcomes, compared with PSF at 2 years. Re-operation rates, however, were higher in the Coflex cohort. Patients in the fusion cohort experienced significantly increased superior and inferior level angulation and translation, while those in the Coflex cohort experienced no significant adjacent or index level radiographic changes from baseline. Coflex Interlaminar Stabilization is a less invasive, safe, and equally effective clinical solution to PSF to treat low-grade spondylolisthesis, and it appears to reduce stresses at the adjacent levels.

lack of patient blinding,
these studies did not assess the effectiveness of a fusion group consisting of lumbar intervertebral cages or BMP, and
it is possible a subset of patients with a stable slip and with minimal back pain may benefit from decompression only, without the need for stabilization.

Furthermore, long-term data are needed to ascertain if motion preservation with the Coflex device will lead to lower re-operation rates for adjacent level disease compared with fusion.

Also, an UpToDate review on ” Subacute and chronic low back pain: Surgical treatment” (Chou, 2013) does not mention Coflex/interlaminar stabilization as a therapeutic option.

The pivotal investigational device exemption (IDE) trial for Coflex® Interlaminar Technology was a non-blinded, randomized, multi-center, non-inferiority trial of Coflex® compared to postero-lateral fusion with pedicle screw fixation. A total of 344 patients were randomized in a 2:1 ratio (215 Coflex® and 107 fusion controls, with 22 protocol violators). This study was conducted in a restricted population with numerous exclusion criteria. Compared to fusion, implantation of the Coflex® device required less operative time (98.0 versus 153.2 mins) and resulted in less blood loss (109.7 versus 348.6 cc) and a shorter hospital stay (1.9 versus 3.2 days). Composite clinical success (a combination of a minimum 15-point improvement in Oswestry Disability Index (ODI), no re-operations, no device-related complications, and no epidural steroid injections in the lumbar spine) at 24 months achieved non-inferiority compared to postero-lateral fusion (66.2% Coflex® and 57.7% fusion). Secondary effectiveness criteria, which included the ZCQ, visual analog score (VAS) for leg and back pain, Short Form-12 (SF-12), time to recovery, patient satisfaction, and several radiographic endpoints, tended to favor the Coflex® group by Bayesian analysis. In this analysis, non-overlapping confidence intervals imply statistically reliable group differences. For example, ZCQ composite success was achieved in 78.3% of Coflex® patients (95% confidence interval [CI]: 71.9% to 84.7%) compared to 67.4% of controls (95% CI: 57.5% to 77.3%). The percentage of device-related adverse events was the same for the 2 groups (5.6% Coflex® and 5.6% control), and a similar percentage of asymptomatic spinous process fractures were observed. The FDA considered the data in this non-blinded study to support reasonable assurance of safety and effectiveness for device approval, but approval is conditional on 2 additional studies that will provide longer-term follow-up (in the IDE cohort) and evaluate device performance under actual conditions of use (decompression alone versus decompression with Coflex®).

Wouter et al (2014) commented that the FDA does not demand that the experimental treatment for a device is compared with the “gold standard.” The author noted that interspinous process device (IPD) treatment with bony decompression was approved in the United States,after the publication of an FDA study on IPD treatment (citing Davis, et al., 2013). However, this study did not compare the experimental treatment (IPD) with the “gold standard” (bony decompression) but with another experimental treatment (bony decompression with fixation techniques). Wouter, et al. (2014) noted that most studies of interspinous process devices (IPD) did not compare the results with other interventions and most did not have prospective study designs. The authors stated that it took 30 years (from the introduction of the Wallis IPD in 1984 until 2013) until 2 prospective studies of IPDs were published that compared IPD treatment with conventional (surgical) care (citing Moojen, et al., 2013; Davis, et al., 2013; Moojen, et al., 2010; Stromqvist, et al., 2013). These studies showed that treatment with IPD was not superior to bony decompression without implants and that IPD treatment resulted in a higher reoperation rate (citing Moojen, et al., 2013: Stromqvist, et al., 2013). A third study of an IPD (X-Stop) was terminated because of the high number of reoperations (complications) in the experimental (IPD) group (Lønne, 2013).

Richter et al (2010) reported a prospective case control study of the Coflex® device in 60 patients who underwent decompressive surgery. The 2-year follow-up from this study was published in 2014 (Richter et al). These investigators prospectively evaluated the outcome of symptomatic lumbar spinal stenosis (LSS) treated with decompressive surgery alone in comparison with additional implantation of the Coflex® interspinous device. A total of 62 patients with symptomatic LSS were treated with decompressive surgery; 31 of these patients received an additional Coflex® device. Pre-operatively and post-operatively, disability and pain scores were measured using the ODI, the Roland-Morris Disability Questionnaire, the VAS, and the pain-free walking distance. Patients underwent post-operative assessments at 3, 6, 12, and 24 months including the above-mentioned scores and patient satisfaction. There was a significant improvement (p < 0.001) in the clinical outcome assessed in the ODI, the Roland-Morris Disability Questionnaire, the VAS, and the pain-free walking distance at all times of re-investigation compared with the base line in both groups. Up to 2 years after surgery, there were no significant differences between both groups in all ascertained parameters, including the patient satisfaction and subjective operation decision. The authors concluded that the results of this first prospective controlled study indicated that the additional placement of a Coflex® interspinous device does not improve the already good clinical outcome after decompressive surgery for LSS in the 24-month follow-up interval.

In a randomized controlled trial, Moojen et al (2013) examined if interspinous process device implantation is more effective in the short-term than conventional surgical decompression for patients with intermittent neurogenic claudication due to lumbar spinal stenosis. A total of 203 participants were referred to the Leiden-The Hague Spine Prognostic Study Group between October 2008 and September 2011; 159 participants with intermittent neurogenic claudication due to lumbar spinal stenosis at 1 or 2 levels with an indication for surgery were randomized. A total of 80 participants received an interspinous process device and 79 participants underwent spinal bony decompression. The primary outcome at short-term (8 weeks) and long-term (1 year) follow-up was the Zurich Claudication Questionnaire score. Repeated measurements were made to compare outcomes over time. At 8 weeks, the success rate according to the Zurich Claudication Questionnaire for the interspinous process device group (63%, 95% confidence interval [CI]: 51% to 73%) was not superior to that for standard bony decompression (72%, CI: 60% to 81%). No differences in disability (Zurich Claudication Questionnaire; p = 0.44) or other outcomes were observed between groups during the 1st year. The repeat surgery rate in the interspinous implant group was substantially higher (n = 21; 29%) than that in the conventional group (n = 6; 8%) in the early post-surgical period (p < 0.001). The authors concluded that this double blinded study could not confirm the hypothesized short-term advantage of interspinous process device over conventional “simple” decompression and even showed a fairly high re-operation rate after interspinous process device implantation. Furthermore, for orthopedic studies with implanted device, 1 year follow-up would not be considered long-term.

Mohi Eldin (2014) evaluated the safety and effectiveness of the Coflex Dynamic Distraction Stabilization (DDS) device in treating patients with degenerative diseases of the lumbar spine (DDLS), especially lumbar canal stenosis (LCS), to confirm its indications for implantation and to evaluate the clinical outcomes of patients. This study was part of a multi-center prospective, case-controlled study in Egypt to determine the safety and efficacy of minimally invasive spinal procedures; of these, the Coflex implant, a functionally dynamic U-shaped titanium interspinous implant, was included in the present study. From June 2008 until July 2013, these researchers treated 42 patients with this Coflex procedure. Median follow-up was 22.5 months. At the time of follow-up, all patients completed questionnaires and underwent clinical examination and spinal radiography. A significant number of patients showed pain relief. Pre-operatively, 30/42 (71%) patients complained of moderate or severe low back pain (LBP). Post-operatively, the LBP in 6 (14%) patients did improve, 24 (57%) even showed no low back pain anymore. Mean pre-operative walking distance was less than 1,000m in 36 (86%) patients. Post-operatively, all 42 (100%) patients could walk greater than 1,000m. Significant pain relief (greater than 50%) in months was calculated. Radiological results showed that endplate angles when were acute pre-operatively, always became less acute post-operatively, and the foraminal height always increased. Segmental range of motion (ROM) showed maintenance of the dynamic movements at the operated level. Disc height showed significant changes after the procedure in both anterior and posterior disc heights. The authors noted that merging the clinical and radiological results of the current study suggested that these effects produce a clinical benefit for LCS patients treated with the Coflex spacer. Though this series has limitations of a smaller sample size, it nevertheless confirmed the satisfactory results. These researchers stated that they will continue to follow the patients enrolled in this study, together with new cases and will report on the longer follow-up. This was a small study (n = 42) with mid-term follow-up (median of 22.5 months). There is a lack of data on durability; well-designed studies with more subjects and longer follow-up are needed.

Yuan et al (2017) retrospectively compared the at least 5-year clinical and radiological outcomes of Coflex stabilization and PLIF for lumbar degenerative disease. Eighty-seven consecutive patients with lumbar degenerative disease were retrospectively reviewed. Forty-two patients underwent decompression and Coflex interspinous stabilization (Coflex group), 45 patients underwent decompression and PLIF (PLIF group). Clinical and radiological outcomes were evaluated. Coflex subjects experienced less blood loss, shorter hospital stays and shorter operative time than PLIF (all p < 0.001). Both groups demonstrated significant improvement in Oswestry Disability Index and visual analogue scale back and leg pain at each follow-up time point. The Coflex group had significantly better clinical outcomes during early follow-up. At final follow-up, the superior and inferior adjacent segments motion had no significant change in the Coflex group, while the superior adjacent segment motion increased significantly in the PLIF group. At final follow-up, the operative level motion was significantly decreased in both groups, but was greater in the Coflex group. The reoperation rate for adjacent segment disease was higher in the PLIF group, but this did not achieve statistical significance (11.1% vs. 4.8%, p = 0.277). Both groups provided sustainable improved clinical outcomes for lumbar degenerative disease through at least 5-year follow-up.

In an extension of the study repoted by Davis, et al. in 2013, Musacchio, et al. (2016) reported on five-year outcomes of a prospective, randomized, controlled trial conducted at 21 centers. Patients with moderate to severe lumbar stenosis at one or two contiguous levels and up to Grade I spondylolisthesis were randomized (2:1 ratio) to decompression and interlaminar stabilization (D+ILS; n=215) using the Coflex Interlaminar Stabilization device or decompression and fusion with pedicle screws (D+PS; n=107). Clinical evaluations were made preoperatively and at 6 weeks and 3, 6, 12, 18, 24, 36, 48, and 60 months postoperatively. Overall FDA success criteria required that a patient meet 4 criteria: 1) >15 point improvement in Oswestry Disability Index (ODI) score; 2) no reoperation, revision, removal, or supplemental fixation; 3) no major device-related complication; and 4) no epidural steroid injection after surgery. At 5 years, 50.3% of D+ILS vs. 44% of D+PS patients (p>0.35) met the composite success criteria. Reoperation/revision rates were similar in the two groups (16.3% vs. 17.8%; p >0.90). Both groups had statistically significant improvement through 60 months in ODI scores with 80.6% of D+ILS patients and 73.2% of D+PS patients demonstrating >15 point improvement (p>0.30). VAS, SF-12, and ZCQ scores followed a similar pattern of maintained significant improvement throughout follow-up. On the SF-12 and ZCQ, D+ILS group scores were statistically significantly better during early follow-up compared to D+PS. In the D+ILS group, foraminal height, disc space height, and range of motion at the index level were maintained through 5 years. This study compared the effectiveness of the Coflex device with spinal fusion in spinal stenosis subjects, some with low-grade spondylolisthesis; however, the benefits of spinal fusion in persons with spinal stenosis with low-grade spondylolisthesis are uncertain (see, e.g., Försth, et al., 2016; Puel & Moojen, 2016; Ghogawala, et al., 2016).

The Work Loss Data Institute’s guideline on “Low back – lumbar & thoracic (acute & chronic)” (2013) listed interspinous decompression device (X-Stop) as one of the interventions/procedures that were considered, but was not recommended.

The North American Spine Society (NASS)’s clinical guideline on “Diagnosis and treatment of degenerative lumbar spondylolisthesis” (2014) stated that “There is insufficient and conflicting evidence to make a recommendation for or against the efficacy of interspinous spacers versus medical/interventional treatment in the management of degenerative lumbar spondylolisthesis patients. Grade of Recommendation: I (Insufficient Evidence)”.

Puzzilli et al (2014) evaluated patients who were treated for symptomatic lumbar spinal stenosis with interspinous process decompression (IPD) implants compared with a population of patients managed with conservative treatment. A total of 542 patients affected by symptomatic lumbar spine degenerative disease were enrolled in a controlled trial; 422 patients underwent surgical treatment consisting of X-STOP device implantation, whereas 120 control cases were managed conservatively. Both patient groups underwent follow-up evaluations at 6, 12, 24, and 36 months using the Zurich Claudication Questionnaire, the visual analog scale (VAS) score and spinal lumbar X-rays, CT scans and MR imaging. One-year follow-up evaluation revealed positive good results in the 83.5% of patients treated with IPD with respect to 50% of the non-operative group cases. During the first 3 years, in 38 out of the 120 control cases, a posterior decompression and/or spinal fixation was performed because of unsatisfactory results of the conservative therapy. In 24 (5.7%) of 422 patients, the IPD device had to be removed, and a decompression and/or pedicle screw fixation was performed because of the worsening of neurological symptoms. The authors concluded that these findings supported the effectiveness of surgery in patients with stenosis; IPD may offer an effective and less invasive alternative to classical microsurgical posterior decompression in selected patients with spinal stenosis and lumbar degenerative disk diseases.

Doulgeris et al (2015) compared an interspinous fusion device with posterior pedicle screw system in a lateral lumbar interbody lumbar fusion. These researchers biomechanically tested 6 cadaveric lumbar segments (L1 to L2) under an axial preload of 50N and torque of 5Nm in flexion-extension, lateral bending and axial rotation directions. They quantified range of motion, neutral zone/elastic zone stiffness in the following conditions: intact, lateral discectomy, lateral cage, cage with interspinous fusion, and cage with pedicle screws. A complete lateral discectomy and annulectomy increased motion in all directions compared to all other conditions. The lateral cage reduced motion in lateral bending and flexion/extension with respect to the intact and discectomy conditions, but had minimal effect on extension stiffness. Posterior instrumentation reduced motion, excluding interspinous augmentation in axial rotation with respect to the cage condition. Interspinous fusion significantly increased flexion and extension stiffness, while pedicle screws increased flexion/extension and lateral bending stiffness, with respect to the cage condition. Both posterior augmentations performed equivalently throughout the tests except in lateral bending stiffness where pedicle screws were stiffer in the neutral zone. The authors concluded that a lateral discectomy and annulectomy generated immediate instability. Stand-alone lateral cages restored a limited amount of immediate stability, but posterior supplemental fixation increased stability. Both augmentations were similar in a single level lateral fusion in-vitro model, but pedicle screws are more equipped for coronal stability. They stated that an interspinous fusion is a less invasive alternative than pedicle screws and is potentially a conservative option for various interbody cage scenarios.

Hirsch et al (2015) stated that lumbar spinal stenosis is a major public health issue. Interspinous devices implanted using minimally invasive techniques may constitute an alternative to the reference standard of bony decompression with or without intervertebral fusion. However, their indications remain unclear, due to a paucity of clinical and biomechanical data. These investigators evaluated the effects of four interspinous process devices implanted at L4 to L5 on the intervertebral foramen surface areas at the treated and adjacent levels, in flexion and in extension. Six fresh frozen human cadaver lumbar spines (L2 to sacrum) were tested on a dedicated spinal loading frame, in flexion and extension, from 0 to 10 N·m, after preparation and marking of the L3 to L4, L4 to L5, and L5 to S1 foramina. Stereoscopic 3D images were acquired at baseline then after implantation at L4 to L5 of each of the 4 devices (Inspace®, Synthes; X-Stop®, Medtronic; Wallis®, Zimmer; and Diam®, Medtronic). The surface areas of the 3 foramina of interest were computed. All 4 devices significantly opened the L4 to L5 foramen in extension. The effects in flexion separated the devices into 2 categories. With the 2 devices characterized by fixation in the spinous processes (Wallis® and Diam®), the L4 to L5 foramen opened only in extension; whereas with the other 2 devices (X-Stop® and Inspace®), the L4 to L5 foramen opened not only in extension, but also in flexion and in the neutral position. None of the devices implanted at L4 to L5 modified the size of the L3 to L4 foramen. X-Stop® and Diam® closed the L5 to S1 foramen in extension, whereas the other 2 devices had no effect at this level. The authors concluded that these findings demonstrated that interspinous process devices modified the surface area of the interspinous foramina in-vitro. They stated that clinical studies are needed to clarify patient selection criteria for interspinous process device implantation.

Lee et al (2015) conducted a systematic literature review of interspinous dynamic stabilization, including Diam®, Wallis®, Coflex, and X-STOP®, to assess its safety and efficacy. A literature search was done in Korean and English, by using eight domestic databases which included KoreaMed and international databases, such as Ovid Medline, Embase, and the Cochrane Library. A total of 306 articles were identified, but the animal studies, preclinical studies, and studies that reported the same results were excluded. As a result, a total of 286 articles were excluded and the remaining 20 were included in the final assessment. Two assessors independently extracted data from these articles using predetermined selection criteria. Qualities of the articles included were assessed using Scottish Intercollegiate Guidelines Network (SIGN). The complication rate of interspinous dynamic stabilization has been reported to be 0% to 32.3% in 3- to 41-month follow-up studies. The complication rate of combined interspinous dynamic stabilization and decompression treatment (32.3%) was greater than that of decompression alone (6.5%), but no complication that significantly affected treatment results was found. Interspinous dynamic stabilization produced slightly better clinical outcomes than conservative treatments for spinal stenosis. Good outcomes were also obtained in single-group studies. No significant difference in treatment outcomes was found, and the studies compared interspinous dynamic stabilization with decompression or fusion alone. The authors of the systematic review concluded that no particular problem was found regarding the safety of the technique. Its clinical outcomes were similar to those of conventional techniques, and no additional clinical advantage could be attributed to interspinous dynamic stabilization. However, few studies have been conducted on the long-term efficacy of interspinous dynamic stabilization. Thus, the authors suggest further clinical studies be conducted to validate the theoretical advantages and clinical efficacy of this technique.The Australian Medical Services Advisory Committee (MSAC, 2017) found insufficient evidence to support the Coflex Interlaminar Stabilization device. MSAC considered that the evidence comparing use of the device with decompression and fusion, and with decompression alone, for LSS was too limited to support the listing and no evidence was presented comparing use of the device to other alternatives for mild degenerative instability alone. MSAC noted that any resubmission would require high quality trial evidence that compared the benefits, harms and cost-effectiveness of using the device with decompression alone, and with decompression and fusion. Such a resubmission should also clarify the appropriate patient population who need ‘stabilization’.

Patel et al (2015a) noted that interspinous spacers are a less-invasive treatment alternative compared with surgical decompression for patients with LSS unresponsive to conservative care. High-quality comparative data with these devices are lacking. In a prospective, multi-center, randomized, controlled, IDE non-inferiority trial, these researchers determined the 2-year outcomes in patients with intermittent neurogenic claudication secondary to moderate LSS who were treated with the Superion interspinous process spacer. Patients presenting with intermittent neurogenic claudication secondary to moderate LSS who failed at least 6 months of non-surgical management were randomly allocated to treatment with the Superion spacer or a control spacer (X-Stop) and followed for 2 years. A total of 391 randomized patients were implanted with Superion (n = 190) or control (n = 201) spacers at 29 sites in the U.S. between August 2008 and December 2011. Implants were successfully implanted in 99.5 % of patients with Superion and 99.0 % of control patients. The primary composite end-point of this study was met, which demonstrated that the Superion spacer was non-inferior to the X-Stop spacer. Leg pain, the predominant patient complaint, decreased in severity by 70 % during 2 years in each group. Most (77 %) patients achieved leg pain clinical success (improvement greater than or equal to 20 mm) at 2 years. Back pain clinical success (improvement greater than or equal to 20 mm) was 68 %, with no differences between groups; ODI clinical success (greater than or equal to 15 % point improvement) was achieved in 65 % of patients. The rates of complications and re-operations were similar between groups. The authors concluded that the Superion interspinous process spacer relieved symptoms of intermittent neurogenic claudication secondary to moderate LSS in the majority of patients through 2 years. These researchers stated that the Superion device may represent a reasonable therapeutic option for this patient population.

The authors stated that this study had several drawbacks. The long-term durability of interspinous process spacers is currently unknown and requires further investigation. In addition, the generalizability of these findings may only be applicable to patients with radiographically confirmed moderate LSS with no more than low-grade spondylolisthesis deformities. The finding that patients with a spinous process fracture yielded similar long-term clinical results to patients without a spinous process fracture brought into question the mechanisms of mechanical action of these devices. Finally, a comparison of interspinous process spacers with non-surgical treatment or surgical decompression was not performed; thus this randomized study provided no information on these interesting questions.

Patel et al (2015b) provided the 3-year clinical outcomes from the randomized, controlled FDA IDE trial of the Superion for the treatment of moderate degenerative LSS. The Superion was evaluated in the treatment of subjects aged 45 years or older suffering from symptoms of intermittent neurogenic claudication, secondary to a confirmed diagnosis of moderate degenerative LSS at 1 or 2 contiguous levels from L1 to L5. Patients were treated between June 2008 and December 2011 at 31 investigational sites. A total of 391 subjects were included in the randomized study group consisting of 190 Superion and 201 X-STOP control subjects. The primary composite end-point was individual patient success based on 4 components: improvement in 2 of 3 domains of the Zurich Claudication Questionnaire, no re-operations at the index level, no major implant/procedure-related complications, and no clinically significant confounding treatments. At 3 years, the proportion of subjects achieving the primary composite end-point was greater for Superion (63/120, 52.5 %) than for X-STOP (49/129, 38.0 %) (p = 0.023) and the corresponding success rates exceeded 80 % for each of the individual components of the primary end-point in the Superion group (range of 81 % to 91%). Improvements in back and leg pain severity as well as back- and disease-specific functional outcomes were also maintained through 36 months. The authors concluded that the 3-year outcomes from this RCT demonstrated durable clinical improvement consistently across all clinical outcomes for the Superion in the treatment of patients with moderate degenerative LSS.

These researchers stated that the durable clinical results achieved with the Superion in the current study were further reflected in a low conversion rate to surgical decompression of only 14 % (26/190) at 3 years. This finding may have a profound effect on the health economics and societal costs of treating the increasing number of patients suffering from spinal stenosis. Indeed, approximately 40 % of patients treated conservatively to alleviate early signs of spinal stenosis ultimately require decompression surgery within 10 years due to persistently worsening symptoms. They stated that the use of an InterSpinous Spacer at the appropriate juncture in the continuum of care may obviate the need for decompression surgery in the majority of patients carefully selected in accordance with the approved indications for use. This study provided short-term follow-up data.

Parker et al (2015) noted that LSS is a painful and debilitating condition resulting in healthcare costs totaling tens of billions of dollars annually. Initial treatment consists of conservative care modalities such as physical therapy, NSAIDs, opioids, and steroid injections. Patients refractory to these therapies can undergo decompressive surgery, which has good long-term efficacy but is more traumatic and can be associated with high post-operative AE rates. Interspinous spacers have been developed to offer a less-invasive alternative. These researchers compared the costs and quality adjusted life years (QALYs) gained of conservative care (CC) and decompressive surgery (DS) to a new minimally-invasive interspinous spacer. A Markov model was developed evaluating 3 strategies of care for LSS. If initial therapies failed, the model moved patients to more invasive therapies. Data from the Superion FDA clinical trial, a prospective spinal registry, and the literature were used to populate the model. Direct medical care costs were modeled from 2014 Medicare reimbursements for healthcare services; QALYs came from the SF-12 PCS and MCS components. The analysis used a 2-year time horizon with a 3 % discount rate. CC had the lowest cost at $10,540, while Spacers and DS were nearly identical at about $13,950. CC also had the lowest QALY increase (0.06), while Spacers and DS were again nearly identical (0.28). The incremental cost-effectiveness ratios (ICER) for Spacers compared to CC was $16,300 and for DS was $15,200. The authors concluded that both the Spacer and DS strategies were far below the commonly cited $50,000/QALY threshold and produced several times the QALY increase versus CC, suggesting that surgical care provided superior value (cost/effectiveness) versus sustained conservative care in the treatment of LSS.

The authors stated that the limitations inherent in this study had significant implications for its interpretation. As in many studies using economic models, the treatments were not all randomized against one another. If outcomes were related to patient characteristics, this could cause bias in the comparisons. To address differences in patients at baseline, these investigators modeled failure rates and QALYs gained as a function of baseline ODI, and adjusted when indicated. While small sample sizes, such as those used in this model, did not in themselves cause bias, they did lead to more variable estimates of each treatment’s effectiveness, and thus more uncertainty in the comparisons. This may be especially true during the 2nd year after the procedure, when the original sample size was somewhat reduced. However, this base case failure rates were within the range of other studies. For DS, the failure rate was 9.2 % over 2 years, somewhat higher than 6.8 % from Burnett, but similar to 8.9 % (35/394) reported from the SPORT study. In addition, results from the probabilistic sensitivity analysis (PSA) were similar to the base case analysis, showing higher cost and greater QALYs gained for the surgical strategies compared to the CC strategy. Utility was estimated as a function of age, sex, SF-12 MCS and PCS scores. These researchers did not recognize a utility decrement when a patient suffered an AE or incurred an inpatient rehabilitation facility (IRF) stay; but because these were short-term events, they would have had minor impact on 2-year utility. The QALYS gained by 2 years were also similar to previous studies. For Spacer, the QALY gained was 0.144 which compared to 0.14 from Skidmore and 0.15 from Burnett. Similarly, the DS QALY gained was 0.15, which compared to 0.08 from Skidmore and 0.16 from Burnett and 0.17 from Tosteson. Finally, the analysis was limited to a 2-year time horizon due to the available data. LSS is a lifetime condition, so longer time horizons may be of interest even in the commercial insurance market. It will be important to extend the time horizon of this and other studies as longer-term data become available on interspinous spacers.

Lonne et al (2015) noted that LSS is the most common indication for operative treatment in elderly. Laminectomy has been the “gold standard”, but minimally invasive decompression (MID) is now widely used. Another minimally invasive surgery option is X-Stop showing good result compared with non-operative treatment, but showing higher re-operation rate than laminectomy. In a prospective, multi-center RCT, these researchers compared the effect of X-Stop with MID in patients with neurogenic intermittent claudication due to LSS. These researchers enrolled 96 patients aged 50 to 85 years, with symptoms of neurogenic intermittent claudication within 250-m walking distance and 1- or 2-level LSS, randomized to either MID or X-Stop. Primary outcome was ZCQ in this intention-to-treat (ITT) analysis. Secondary outcome was ODI, EuroQol 5-dimensional questionnaire, NRS 11 for LBP and leg pain, and risk for secondary surgery and complications. No significant differences were found in ZCQ between the groups at any follow-ups. Both groups had a statistical and clinical significant improvement at 6 weeks and throughout the 2-year observation period. The number of patients having secondary surgery due to persistent or recurrent symptoms was significantly higher in the X-Stop group (95 % CI: 6.5 (1.3 to 31.9). Complication rate was similar and low, but more severe for MID. The authors concluded that both MID and X-Stop led to significant symptom improvements. There were no significant clinical differences in effect between the methods at any of the follow-up time points. X-Stop had significant higher risk of secondary surgery. Complication was more severe for MID.

Lauryssen et al (2015) compared the 2-year clinical outcomes of a prospective, RCT of an FDA-approved interspinous spacer with the compilation of published findings from 19 studies of decompressive laminectomy for the treatment of LSS. Back and leg pain, ODI, and ZCQ values were compared between spacer- and laminectomy-treated patients pre-operatively and at 12 and 24 months. Percentage improvements between baseline and 24 months uniformly favored patients treated with the spacer for back pain (65 % versus 52 %), leg pain (70 % versus 62 %), ODI (51 % versus 47 %) and ZCQ symptom severity (37 % versus 29 %) and physical function (36 % versus 32 %). The authors concluded that both treatments provided effective and durable symptom relief of claudicant symptoms. This stand-alone interspinous spacer offered the patient a minimally invasive option with less surgical risk. This study provided short-term follow-up data (24 months).

Nunley et al (2017a) determined the 4-year clinical outcomes in patients with moderate LSS treated with minimally invasive stand-alone interspinous process decompression using the Superion device. The 4-year Superion data were extracted from a randomized, controlled FDA IDE. Patients with intermittent neurogenic claudication relieved with back flexion who failed at least 6 months of non-surgical management were enrolled. Outcomes included ZCQ symptom severity (ss), physical function (pf) and patient satisfaction (ps) subdomains, leg and back pain VAS, and ODI. At 4-year follow-up, 89 of the 122 patients (73 %) provided complete clinical outcome evaluations. At 4 years after index procedure, 75 of 89 patients with Superion (84.3 %) demonstrated clinical success on at least 2 of 3 ZCQ domains. Individual component responder rates were 83 % (74/89), 79 % (70/89), and 87 % (77/89) for ZCQss, ZCQpf, and ZCQps; 78 % (67/86) and 66 % (57/86) for leg and back pain VAS; and 62 % (55/89) for ODI. Patients with Superion also demonstrated percentage improvements over baseline of 41 %, 40 %, 73 %, 69 %, and 61 % for ZCQss, ZCQpf, leg pain VAS, back pain VAS, and ODI. Within-group effect sizes all were classified as very large (greater than 1.0): 1.49, 1.65, 1.42, 1.12, and 1.46 for ZCQss, ZCQpf, leg pain VAS, back pain VAS, and ODI. The authors concluded that minimally invasive implantation of the Superion device provided long-term, durable relief of symptoms of intermittent neurogenic claudication for patients with moderate lumbar spinal stenosis

Nunley et al (2017b) stated that lumbar spinal stenosis is the most common indication for spine surgery in older adults. Interspinous process decompression (IPD) using a stand-alone spacer that functions as an extension blocker offers a minimally invasive therapeutic option for intermittent neurogenic claudication associated with spinal stenosis. This study evaluated the 5-year clinical outcomes for IPD (Superion®) from a randomized controlled FDA non-inferiority trial. Outcome measures included Zurich Claudication Questionnaire (ZCQ) symptom severity (ss), physical function (pf), and patient satisfaction (ps) subdomains, leg and back pain visual analog scale (VAS), and Oswestry Disability Index (ODI). At 5 years, 84% of patients (74 of 88) demonstrated clinical success on at least 2 of 3 ZCQ domains. Individual ZCQ domain success rates were 75% (66 of 88), 81% (71 of 88), and 90% (79 of 88) for ZCQss, ZCQpf, and ZCQps, respectively. Leg and back pain success rates were 80% (68 of 85) and 65% (55 of 85), respectively, and the success rate for ODI was 65% (57 of 88). Percentage improvements over baseline were 42%, 39%, 75%, 66%, and 58% for ZCQss, ZCQpf, leg and back pain VAS, and ODI, respectively (all p < 0.001). Within-group effect sizes were classified as very large for 4 of 5 clinical outcomes (i.e., greater than 1.0; all p < 0.0001); 75% of IPD patients were free from re-operation, revision, or supplemental fixation at their index level at 5 years. The authors concluded that after 5 years of follow-up, IPD with a stand-alone spacer provided sustained clinical benefit. Financial support for this work was provided by VertiFlex, Inc. (Carlsbad, CA).

Zhao et al (2017) stated that IPD were widely used for the treatment of lumbar spinal stenosis (LSS). However, whether IPD was superior to bony decompression (DP) was still debated. These investigators compared the clinical outcomes of IPD to DP for LSS. PubMed, Cochrane library, Cochrane Central Register of Controlled Trials (CCTR), Ovid Medline, China national knowledge internet database, Wan Fang database were searched on August 8,2016. Studies were identified using selection criteria and analysis was performed with Review Manager Version 5.3. A total of 4 RCTs (7 articles) were included, with 200 patients in the IPD group and 200 patients in DP group. There was no significant difference in hospital stay time (p = 0.36), VAS leg pain scores (p = 0.83), and complication rates (p = 0.20) for IPD alone versus DP. However, IPD alone showed higher VAS low back pain scores (p = 0.03) and re-operation rates (p < 0.0001) between the 2 therapy groups. Two studies’ results showed the IPD group had lower cost-effectiveness. The authors concluded that although patients who received IPD may obtain several benefits in the short-term, it was associated with higher costs, re-operation rates. These researchers stated that larger sample size studies and longer follow-up are needed to evaluate the IPD.

Poetscher et al (2018) noted that degenerative LSS is a condition related to aging in which structural changes cause narrowing of the central canal and intervertebral foramen. It is currently the leading cause for spinal surgery in patients over 65 years; IPDs were introduced as a less invasive surgical alternative, but questions regarding safety, efficacy, and cost-effectiveness are still unanswered. These researchers provided complete and reliable information regarding benefits and harms of IPDs when compared to conservative treatment or decompression surgery and suggested directions for forthcoming RCTs. They searched Medline, Embase, Cochrane Library, Scopus, and LILACS for randomized and quasi-randomized trials, without language or period restrictions, comparing IPDs to conservative treatment or decompressive surgery in adults with symptomatic degenerative LSS. Data extraction and analysis were conducted following the Cochrane Handbook. Primary outcomes were pain assessment, functional impairment, ZCQ, and re-operation rates. Secondary outcomes were quality of life (QOL), complications, and cost-effectiveness. The search strategy resulted in 17 potentially eligible reports. At the end, 9 reports were included and 8 were excluded. Overall quality of evidence was low; 1 trial compared IPDs to conservative treatment: IPDs presented better pain, functional status, QOL outcomes, and higher complication risk; 5 trials compared IPDs to decompressive surgery: pain, functional status, and QOL had similar outcomes; IPD implant presented a significantly higher risk of re-operation. These investigators found low-quality evidence that IPDs resulted in similar outcomes when compared to standard decompression surgery. Primary and secondary outcomes were not measured in all studies and were often published in incomplete form. Sub-group analysis was not feasible. Difficulty in contacting authors may have prevented us of including data in quantitative analysis. The authors concluded that patients submitted to IPD implants had significantly higher rates of re-operation, with lower cost-effectiveness. These researchers stated that future trials should improve in design quality and data reporting, with longer follow-up periods. They stated that until conclusive evidence becomes available, therapeutic options must be chosen very carefully on an individual patient basis, with full disclosure of unproven clinical benefits and presumably higher risk of re-operation.

Nunley et al (2018a) noted that LSS causes significant pain and functional impairment, and medical management has increasingly included the prescription of opioid-based analgesics; IPD provides a minimally-invasive therapeutic option for LSS. This study estimated the type, dosage, and duration of opioid medications through 5 years of follow-up after IPD with the Superion Indirect Decompression System. Data were obtained from the Superion-treatment arm of a randomized controlled non-inferiority trial. The prevalence of subjects using opiates was determined at baseline through 60 months. Primary analysis included all 190 patients randomized to receive the Superion device. In a subgroup of 98 subjects, these investigators determined opioid-medication prevalence among subjects with a history of opioid use. At baseline, almost 50 % (94 of 190) of subjects were using opioid medication. Thereafter, there was a sharp decrease in opioid-medication prevalence from 25.2 % (41 of 163) at 12 months to 13.3 % (20 of 150) at 24 months to 7.5 % (8 of 107) at 60 months. Between baseline and 5 years, there was an 85 % decrease in the proportion of subjects using opioids. A similar pattern was also observed among subjects with a history of opiates prior to entering the trial. The authors concluded that stand-alone IPD was associated with a marked decrease in the need for opioid medications to manage symptoms related to LSS. In light of the current opiate epidemic, such alternatives as IPD may provide effective pain relief in patients with LSS without the need for opioid therapy.

The authors stated that this study had several limitations. In the absence of a non-surgical control, these researchers were unable to estimate the comparative natural history of opioid usage among LSS patients treated conservatively. Although medication prescribing was captured on a compulsory basis for all study subjects, the trial was not designed to evaluate opioid usage as a primary or secondary outcome. As an ancillary variable, data collection methods lacked a standardized methodology to quantify opioid usage. Consequently, this post-hoc analysis was constrained to prevalence estimates within specified post-operative follow-up intervals and limited only to those patients who remained implanted with the study device and who were free of a re-operation at the index surgical level.

Deer et al (2019a) stated that LSS can lead to compression of neural elements and manifest as LBP and leg pain. LSS has traditionally been treated with a variety of conservative (pain medications, physical therapy, epidural spinal injections) and invasive (surgical decompression) options. Recently, several minimally invasive procedures have expanded the therapeutic options. The Lumbar Spinal Stenosis Consensus Group convened to evaluate the peer-reviewed literature as the basis for making minimally invasive spine treatment (MIST) recommendations. A total of 11 consensus points were clearly defined with evidence strength, recommendation grade, and consensus level using U.S. Preventive Services Task Force criteria. The Consensus Group also created a treatment algorithm. Literature searches yielded 9 studies (2 RCTs; 7 observational studies, 4 prospective and 3 retrospective) of minimally invasive spine treatments, and 1 RCT for spacers. The LSS therapeutic choice is dependent on the degree of stenosis; spinal or anatomic level; architecture of the stenosis; severity of the symptoms; failed, past, less invasive treatments; previous fusions or other open surgical approaches; and patient co-morbidities. There is Level I evidence for percutaneous image-guided lumbar decompression as superior to lumbar epidural steroid injection, and 1 RCT supported spacer use in a non-inferiority study comparing 2 spacer products currently available. The authors concluded that MISTs should be used in a judicious and algorithmic fashion to treat LSS, based on the evidence of safety and efficacy in the peer-reviewed literature. The MIST Consensus Group recommended that these procedures be used in a multi-modal fashion as part of an evidence-based decision algorithm.

In a review on “The emerging evidence for utilization of a percutaneous interspinous process decompression device to treat symptomatic lumbar adjacent-segment degeneration”, Deer et al (2019b) concluded that “Indirect lumbar decompression via interspinous spacer is an emerging minimally invasive technique for patients with a history of implanted spinal cord stimulators or spinal instrumentation who continue to experience symptoms due to progressive neurogenic claudication”.

Zini et al (2019) examined the literature regarding IPD that mainly focused on comparison with conservative treatment and surgical decompression for the treatment of degenerative LSS (DLSS). The authors noted that IPD are diverse mini-invasive devices placed with fluoroscopic guidance under local anesthesia between the spinal processes at the DLSS level in order to obtain nerve decompression. It has been demonstrated to be more effective than a conservative treatment for DLSS; treatment failure appeared to be significantly lower in the IPD group, while complications appeared to be more frequent for the implant group compared to the conservative treatment. These researchers stated that low quality evidence indicated that outcomes regarding pain, functional status and QOL were similar comparing IPD with surgical procedures; however, treatment failure was significantly higher in IPD group compared to decompressive surgery because of complication as dislocation of the device and erosion/fracture of the spinous process that could be avoided with spinoplasty or “lack of success” almost related to patient selection; cost-effectiveness of IPD is still being debated. The authors concluded that a prospective, randomized study to evaluate the efficacy of pure percutaneous IPD plus preventive spinoplasty versus spinal laminectomy with long (greater than 24 months) term follow-up is highly desirable.

Falowski et al (2019) stated that interspinous process spacers are used in the treatment of (LSS by preventing extension at the implanted level and reducing claudication, which is a common symptom of LSS. These investigators examined the current safety and performance of LSS treatments and the biomechanical effects of spinal position, ROM, and the use of interspinous process spacers. These investigators searched Embase and PubMed to identify studies reporting on the safety and performance of non-surgical treatment, including physical therapy (PT) and pharmacological treatment, and surgical treatment, including direct and indirect lumbar decompression treatment. Results were supplemented with manual searches to include studies reporting on the use of interspinous process spacers and the review of biomechanical testing performed on the Superion device. The effects of spinal position in extension and flexion have been shown to have an impact in the variation in dimensions of the spinal canal and foramina areas. Overall studies have shown that spinal positions from flexion to extension reduced the spinal canal and foramina dimensions and increased ligamentum flavum thickness. Biomechanical test data have shown that the Superion device resisted extension and reduced angular movement at the implantation level and provided significant segmental stability. The authors concluded that Superion interspinous lumbar decompression was a minimally invasive, low-risk procedure for the treatment of LSS, which has been shown to have a low safety profile by maintaining sagittal alignment, limiting the potential for device dislodgment or migration, and to preserve mobility and structural elements.

Merkow et al (2020) noted that symptomatic LSS is a condition affecting a growing number of individuals resulting in significant disability and pain. Traditionally, therapeutic options have consisted of conservative measures such as physical therapy, medication management, epidural injections and percutaneous adhesiolysis, or surgery. There exists a treatment gap for patients failing conservative measures who are not candidates for surgery. Minimally invasive lumbar decompression (MILD) and IPD with Superion represent minimally invasive novel therapeutic options that may help fill this gap in management. These researchers carried out a literature review to examine these procedures and evaluate their safety and effectiveness. The available evidence for MILD and Superion has been continuously debated. Overall, it is considered that while the procedures are safe, there is only modest evidence for effectiveness. For both procedures, these investigators have reviewed 13 studies. Based on the available evidence, MILD and Superion are safe and modestly effective minimally invasive procedures for patients with symptomatic LSS. It is the authors’ recommendation that these procedures may be incorporated as part of the continuum of therapeutic options for patients meeting clinical criteria.

In a retrospective review, Tram et al (2020) examined the literature on the efficacy and complications associated with decompression and interspinous devices (ISDs) used in surgeries for LSS. LSS is a debilitating condition that affects the lumbar spinal cord and spinal nerve roots; however, a comprehensive report on the relative efficacy and complication rate of ISDs as they are compared to traditional decompression procedures is currently lacking. The PubMed data-base was queried to identify clinical studies that exclusively investigated decompression, those that exclusively investigated ISDs, and those that compared decompression with ISDs. Only prospective cohort studies, case series, and RCTs that evaluated outcomes using the VAS, ODI, or JOA scores were included. A random-effects model was established to assess the difference between pre-operative and the 1- to 2-year post-operative VAS scores between ISD surgery and lumbar decompression. This study included 40 papers that matched the selection criteria. A total of 25 decompression-exclusive clinical trials with 3,386 patients and a mean age of 68.7 years (range of 31 to 88 years) reported a 2.2 % incidence rate of dural tears and a 2.6 % incidence rate of post-operative infections. A total of 8 ISD-exclusive clinical trials with 1,496 patients and a mean age of 65.1 (range of 19 to 89 years) reported a 5.3 % incidence rate of post-operative leg pain and a 3.7 % incidence rate of spinous process fractures; 7 studies that compared ISDs and decompression in 624 patients found a re-operation rate of 8.3 % in ISD patients versus 3.9 % in decompression patients; they also reported dural tears in 0.32 % of ISD patients versus 5.2 % in decompression patients. A meta-analysis of the RCTs found that the differences in pre-operative and post-operative VAS scores between the 2 groups were not significant. Both decompression and ISD interventions were unique surgical interventions with different therapeutic efficacies and complications. The authors concluded that the collected studies did not consistently demonstrate superiority of either procedure over the other but understanding the differences between the 2 techniques could help tailor treatment regimens for patients with LSS. These researchers stated that careful patient selection remains crucial for either surgical procedure to ensure optimal surgical outcomes tailored to each patient. They stated that more diverse studies are needed to determine the superiority of one technique over the other for different patient populations.

The authors stated that limitations of this study included inconsistent reporting of measurements among studies. Inconsistencies were also found in the extent of complications reported, with more exhaustive studies reporting unique complications, while some studies simply stated that no major complications were encountered. Another limitation of this paper was the variation in post-operative care, which was important for long-term complications such as re-operation rates.

Furthermore, an UpToDate review on “Lumbar spinal stenosis: Treatment and prognosis” (Levin, 2020) states that “Intraspinous spacer implantation – A potentially less invasive treatment option involves implanting a device between the spinous processes at one or two vertebral levels, relieving compression. This procedure is said to be appropriate for those patients with spinal stenosis without spondylolisthesis who have intermittent claudication symptoms that are exacerbated in extension and relieved in flexion. A randomized, multicenter study in 191 patients compared the implantation of the X STOP implant, a titanium alloy device, with nonoperative treatment. At 6 months, symptoms were relieved in 52 % of treated patients, compared with 9 % of controls. Benefit was maintained at 2 and 4 years of follow-up and was associated with reduced disability and improved quality of life. Subsequent uncontrolled observations have found that implantation of the X STOP device has been efficacious in many patients, if not in as large a proportion as was found in the clinical trial. While radiologic improvement in spinal canal and neuroforaminal narrowing can be measured after surgery, these changes are not correlated with clinical benefit and are not maintained over time in most patients. These procedures appear to be associated with higher rates of subsequent surgery than patients initially treated with laminectomy. Adverse effects also appear to be more commonly reported in general clinical experience; these include discitis/osteomyelitis, device dislocations, spinous process fractures, recurrent disc herniation, hematoma, cerebrospinal fluid fistula, and foot drop. It is unclear how this newer procedure compares with the standard surgical procedure, decompressive laminectomy, in terms of effectiveness, side effects, recovery time, and long-term outcomes. This treatment does not appear to be helpful in patients who have spondylolisthesis”. Furthermore, intraspinous spacer implantation is not listed in the “Summary and Recommendations” section of this review.

Whang et al (2023) noted that for individuals with LSS, minimally invasive procedures such as an interspinous spacer device without decompression or fusion (ISD) or open surgery (i.e., open decompression or fusion) may relieve symptoms and improve functions when patients fail to respond to conservative therapies. In a retrospective, comparative claims analysis, these investigators compared longitudinal post-operative outcomes and rates of subsequent interventions between LSS patients treated with ISD and those with open decompression or fusion as their 1st surgical intervention. They identified patients aged 50 years or older with LSS diagnosis and with a qualifying procedure during 2017 and 2021 in the Medicare database that included healthcare encounters in inpatient as well as outpatient settings. Patients were followed from the qualifying procedure until end of data availability. The outcomes evaluated during the follow-up included subsequent surgical interventions, including subsequent fusion and lumbar spine surgeries, long-term complications, and short-term life-threatening events. Furthermore, the costs to Medicare during a 3-year follow-up were calculated. Cox proportional hazards, logistic regression, and generalized linear models were used to compare outcomes and costs, adjusted for baseline characteristics. A total of 400,685 patients who received a qualifying procedure were identified (mean age of 71.5 years, 50.7 % men). Compared to ISD patients, patients receiving open surgery (i.e., decompression and/or fusion) were more likely to have a subsequent fusion [HR, 95 % CI: 1.49 (1.17, 1.89) to 2.54 (2.00, 3.23)] or other lumbar spine surgery [HR (CI): 3.05 (2.18, 4.27) to 5.72 (4.08, 8.02)]. Short-term life-threatening events [OR (CI): 2.42 (2.03, 2.88) to 6.36 (5.33, 7.57)] and long-term complications [HR (CI): 1:31 (1.13, 1.52) to 2.38 (2.05, 2.75)] were more likely among the open surgery cohorts. Adjusted mean index costs were lowest for decompression alone (US$ 7,001) and highest for fusion alone (US$ 33,868). ISD patients had significantly lower 1-year complication-related costs than all surgery cohorts and lower 3-year all-cause costs than fusion cohorts. The authors concluded that ISD resulted in lower risks of short- and long-term complications and lower long-term costs than open decompression and fusion surgeries as a 1rst surgical intervention for LSS. Moreover, these researchers stated that future investigations on clinical data, opioid and pain-related medication use, and healthcare utilizations would provide additional understanding of how spinal procedures impact the healthcare system and patient outcomes.

The authors stated that this study had several limitations including those inherent to these types of claims analyses, such as the potential for coding or data entry errors and the omission of details not needed to justify payment. For instance, diagnosis codes identified in claims data lack the clinical information such as the severity of LSS or post-operative complications, so the severity of LSS at the time of index procedure could not be determined, nor could outcomes be examined by severity. Furthermore, the inability of claims to capture imaging data or patient-reported outcomes, such as visual or numeric pain scores and the Zurich Claudication Questionnaire, made it impossible to examine the effectiveness of the procedure. In addition, this analysis was limited to individuals with Medicare coverage; thus, they may not be generalizable to other patients; however, this may be less of a concern because the vast majority of symptomatic LSS cases were adults aged 65 years and older who generally have Medicare coverage.

Rosner et al (2024) noted that treatment for degenerative LSS usually begins with conservative care and progresses to minimally invasive procedures, including ISD or MILD. In a retrospective study, these researchers examined safety outcomes and the rate of subsequent spinal procedures among LSS patients receiving an ISD versus MILD as the 1st surgical intervention. These investigators used 100 % Medicare Standard Analytical Files to identify patients with an ISD or MILD (1st procedure = index date) from 2017 to 2021. ISD and MILD patients were matched 1:1 using propensity score matching based on demographics and clinical characteristics. Safety outcomes and subsequent spinal procedures were captured from index date until end of follow-up. Cox models were used to analyze rates of subsequent surgical interventions, LSS-related interventions, open decompression, fusion, ISD, and MILD. Cox models were used to evaluate post-operative complications during follow-up and logistic regression to analyze life-threatening complications within 30 days of index procedure. A total of 3,682 ISD and 5,499 MILD patients were identified. After matching, 3,614 from each group were included in the analysis (mean age = 74 years, mean follow-up = 20.0 months). The risk of undergoing any intervention, LSS-related intervention, open decompression, and MILD were 21 %, 28 %, 21 %, and 81 % lower among ISD compared with MILD patients. Multi-variate analyses showed no significant differences in the risk of undergoing fusion or ISD, experiencing post-operative complications, or life-threatening complications (all p ≥ 0.241) between the cohorts. The authors concluded that the findings of this study showed that ISD and MILD procedures exhibited equivalent safety profile; however, ISDs showed lower rates of open decompression and MILD.

The authors stated that the limitations of this study included those inherent in any retrospective claims analysis; namely that the data rely on administrative claims for clinical details. These data were subject to data coding limitations and data entry error. For example, diagnosis codes may lack detail and activities not needed to justify payment may be omitted. Claims also do not capture imaging data or patient-reported outcomes that are relevant to examine the effectiveness of the index procedure; namely visual or numeric pain scores and ZCQ responses. Furthermore, it is not possible to capture the severity of LSS (or the severity of complications) from claims, so the severity of LSS at the time of index procedure could not be determined, nor could outcomes be examined by LSS severity. In addition, as a result, these researchers were unable to adjust for these factors in the Cox or logistic regression models. It should also be noted that patients were not randomized to treatment groups in this retrospective study and that MILD and ISD did not have identical clinical indications (for MILD, stenosis must occur with hypertrophied ligamentum flavum), which could result in implicit bias in patient selection. Furthermore, the primary results in this study were limited to individuals with Medicare coverage, and consequently, results of this analysis may not be generalizable to patients with other insurance or without health insurance coverage. However, due to the high prevalence of LSS in adults aged 65 and older who have Medicare insurance coverage, this analysis did represent a large proportion of eligible patients. (This study was supported by Boston Scientific).

Furthermore, an UpToDate review on “Lumbar spinal stenosis: Treatment and prognosis” (Levin, 2023) states that “Intraspinous spacer implantation – A potentially less invasive treatment option involves implanting a device between the spinous processes at 1 or 2 vertebral levels, relieving compression. This procedure is said to be appropriate for those patients with spinal stenosis without spondylolisthesis who have intermittent claudication symptoms that are exacerbated in extension and relieved in flexion. A randomized, multicenter study in 191 patients compared the implantation of the X STOP implant, a titanium alloy device, with nonoperative treatment. At 6 months, symptoms were relieved in 52 % of treated patients, compared with 9 % of controls. Benefit was maintained at 2 and 4 years of follow-up and was associated with reduced disability and improved quality of life. Subsequent uncontrolled observations have found that implantation of the X STOP device has been efficacious in many patients, if not in as large a proportion as was found in the clinical trial. While radiologic improvement in spinal canal and neuroforaminal narrowing can be measured after surgery, these changes are not correlated with clinical benefit and are not maintained over time in most patients. These procedures appear to be associated with higher rates of subsequent surgery than patients initially treated with laminectomy. Adverse effects also appear to be more commonly reported in general clinical experience; these include discitis/osteomyelitis, device dislocations, spinous process fractures, recurrent disc herniation, hematoma, cerebrospinal fluid fistula, and foot drop. It is unclear how this newer procedure compares with the standard surgical procedure, decompressive laminectomy, in terms of effectiveness, side effects, recovery time, and long-term outcomes. This treatment does not appear to be helpful in patients who have spondylolisthesis”. Intraspinous spacer is NOT mentioned I the “Summary and Recommendations” section of this UTD review.

Interspinous Fixation Devices

Spinous process fixation is promoted as a minimally invasive spine surgery technique that stabilizes the lumbar spine with less dissection and trauma to the vertebra than the current gold standard, pedicle screw (PS) fixation (Lopez, et al., 2016). Interspinous fixation devices (IFD) aim to provide rigidity comparable with PS fixation by bilaterally securing plates to the lateral aspects of 2 adjacent spinous processes, effectively clamping the motion segment together. IFD implantation has been applied to posterolateral and interbody fusion procedures. Certain IFD products are designed to achieve additional stability through interspinous bony fusion. Proponents have noted that IFD placement is a more expedient procedure that requires a single, less obtrusive midline incision. Multiple IFDs have been designed and are indexed in the literature using various terminology, including spinous process clamps, plates, and anchors. These are not to be confused with interspinous spacers” (X-Stop®, Wallis®, or Diam® devices), which reduce extension through dynamic stabilization with the aim of decreasing symptoms of lumbar spinal stenosis.

Lopez et al (2016) systematically reviewed the available literature on interspinous rigid fixation/fusion devices (IFD) to explore the devices’ efficacy and complication profile. A systematic review of the past 10 years of English literature was conducted according to PRISMA guidelines. The timeframe was chosen based on publication of the first study containing a modern IFD, the SPIRE, in 2006. All PubMed publications containing MeSH headings or with title or abstract containing any combination of the words “interspinous,” “spinous process,” “fusion,” “fixation,” “plate,” or “plating” were included. Exclusion criteria consisted of dynamic stabilization devices (X-Stop®, Diam®, etc.), cervical spine, pediatrics, and animal models. The articles were blinded to author and journal, assigned a level of evidence by Oxford Centre of Evidence-Based Medicine (OCEBM) criteria, and summarized in an evidentiary table. A total of 293 articles were found in the initial search, of which 15 remained after examination for exclusion criteria. No class I or class II evidence regarding IFDs was found. IFDs have been shown by methodologically flawed and highly biased class III evidence to reduce instability at 1 year, without statistical comparison of complication rates against other treatment modalities.

Hartman et al (2019) noted that the use of the Vertiflex interspinous spacer is a recent minimal invasive procedure useful in the treatment of lumbar spinal stenosis (LSS). It is used mostly by interventional pain physicians who can also perform the minimally invasive lumbar decompression (MILD procedure). Previously when a patient had clinical symptomatic neurogenic claudication (NC) and radiologic findings of lumbar stenosis and had failed conservative treatment, the options were decompressive laminectomy, laminectomy with pedicle fixation at 1 or more levels or laminotomy combined with interlaminar stabilization (Coflex implant). These procedures were performed by neurosurgeons and orthopedic spine surgeons. However, the majority of patients with LSS are elderly and have multiple co-morbidities that could make open spinal surgery, even when limited to 1 level, an anesthesia risk as well as vulnerable to the risk associated with hospitalization and recovery after spine surgery. The minimally invasive approaches to interspinous stabilization make it possible to treat localized symptomatic stenosis in a broader group of patients that do not want or could not, have general anesthesia or extensive lumbar surgery, especially in the prone position. The authors examined the use of the Vertiflex implant in an elderly population with significant co-morbidities who underwent successful outpatient implantation at 1 or 2 levels. This article looked at the role of medical co-morbidities that may make larger open surgery and general anesthesia higher risk or even contraindicated. The treating physician’s specialty and experience with different procedures must also be considered as well as the age, anesthesia risk and co-morbidities such as obesity, diabetes and cardio-pulmonary restrictions that may make the option of procedures such as MILD or Vertiflex reasonable. This study did not provide any clinical data regarding the effectiveness of the Vertiflex device for the treatment of LSS.

Tekmyster et al (2019) stated that interspinous process decompression (IPD) used the Superion Indirect Decompression System (Vertiflex, Carlsbad, CA). Peri-operative and clinical data were captured via a registry for patients treated with IPD for LSS with intermittent NC. A total of 316 physicians at 86 clinical sites in the U.S. participated in this medical device registry. Patient data were captured from in-person interviews and a phone survey. Outcomes included intra-operative blood loss, procedural time, leg and back pain severity (100-mm VAS), patient satisfaction and treatment approval at 3 weeks, 6 and 12 months. The mean age of registry patients was 73.0 ± 9.1 years of which 54 % were women. Mean leg pain severity decreased from 76.6 ± 22.4 mm pre-operatively to 30.4 ± 34.6 mm at 12 months, reflecting an overall 60 % improvement. Corresponding responder rates were 64 % (484 of 751), 72 % (1,097 of 1,523) and 75 % (317 of 423) at 3 weeks, 6 and 12 months, respectively. Back pain severity improved from 76.8 ± 22.2 mm pre-operatively to 39.9 ± 32.3 mm at 12 months (48 % improvement); 12-month responder rate of 67 % (297 of 441). For patient satisfaction at 3 weeks, 6 and 12 months, 89 %, 80 %, and 80 % were satisfied or somewhat satisfied with their treatment and 90 %, 75 %, and 75 % would definitely or probably undergo the same treatment again. In the phone survey, the rate of revision was 3.6 % (51 of 1,426). The authors concluded that these registry findings supported the clinical adoption of minimally invasive IPD in patients with NC associated with LSS. It should be noted that financial support for this work was provided by Vertiflex, Inc. Furthermore, GT reported grants from Vertiflex, during the conduct of the study. DS reported personal fees from Vertiflex, outside the submitted work. KC was paid for time to enroll patients and track data in PRESS registry from Vertiflex, during the conduct of the study. He also received personal fees from Boston Scientific and Vertiflex, outside the submitted work. LJR serves as consultant/instructor for Vertiflex and Boston Scientific. JEB is an independent advisor to Vertiflex and was remunerated for assistance in manuscript development.

In a retrospective analysis, Falowski et al (2021) examined the use of an interspinous fixation (ISF) device as performed by interventional pain physicians. These investigators identifying 32 patients with the diagnosis of lumbar degenerative disc disease (DDD) with secondary diagnosis of LSS being treated with ISF with Aurora Spine Zip Interspinous Spacer. Serious adverse events (AEs), specifically nerve injury, hematoma, infection, and death, were analyzed quantitatively for reported complications within 90 days from the procedure. Furthermore, visual analog scale (VAS) was analyzed for patient reported outcomes; AE rate was 0 % with no incidences of re-operation, or device removal. Estimated blood loss (EBL) was recorded as less than 50 cc for all patients. The pre-operative pain assessment demonstrated an average pain score of 8.1 and a post-operative pain score of 2.65 equating to a percentage pain reduction of 67 %. The authors concluded that this promising case series added another potential tool to the armamentarium of the interventional pain physician in the treatment of moderate-to-severe LSS and DDD. This broadens the application to degenerative changes, spondylolisthesis, and multiple pain generators such as disc degeneration and facet joint hypertrophy, which is not treated by indirect decompression alone such as with an interspinous spacer. It is an option to patients who have decreased morbidity and significant efficacy. Moreover, these researchers stated that a prospective, multi-center study is planned to further evaluate the effectiveness of this implant in terms of a composite patient success endpoint, including function, pain relief, disability, and AEs.

The authors stated that drawbacks of the study included its retrospective nature, lack of functional outcome measures, region-specific pain scores, and detailed analysis of patient demographics including quantitative radiographic analysis, and physical examination.

Welton et al (2021) noted that current evidence suggests placement of the Superion interspinous spacer (SISS) device compared with laminectomy or laminotomy surgery offers an effective, less invasive therapeutic option for patients with symptomatic lumbar spinal stenosis (LSS). Both SISS placement and laminectomy or laminotomy have risks of complications and a direct comparison of complications between the 2 procedures has not been previously studied. In a retrospective review, these researchers compared the short-term complications of the SISS with laminectomy or laminotomy and highlighted device-specific long-term outcomes with SISS. A total of 189 patients who received lumbar level SISSs were compared with 378 matched controls who underwent primary lumbar spine laminectomy or laminotomy; data were collected from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Complications analyzed included rates of wound infection, pulmonary embolism (PE), deep venous thrombosis (DVT), urinary tract infection (UTI), sepsis, septic shock, cardiac arrest, death, as well as re-operation within 30 days of index surgery. Differences between groups were analyzed using the χ2 test. Device-specific complication (DSC) rates included device malfunction or misplacement (DM), device explantation (DE), spinous process fracture (SPF), and subsequent spinal surgery (SSS). No differences in demographics or co-morbidities existed between groups. There was no significant difference in rates of complications between groups. A total of 44.4 % of patients in the SISS group experienced DSCs with 11.1 % of patients experiencing DM, 21.1 % experiencing an SPF, 20.1 % requiring DE, and 24.3 % requiring SSS. Having at least 1 DSC significantly increased odds of SSS, odds ratio (OR) > 120, p < 0.0001. The authors concluded that rates of 30-day complications in the SISS group were not significantly different from patients undergoing laminectomy or laminotomy. Rates of 2-year DSC within SISS and cumulative risk associated with these complications should be studied further as they likely represent a substantial additional cost to the healthcare system that may not be justified by improved patient outcomes. Level of Evidence = IV.

These researchers stated that this study was limited by its retrospective design and the comparison of 2 separate data sets that were both gathered before their investigation. Comparing 2 separate databases limited the ability to match patients. Each data set contained unique and limited variables that dictated what characteristics these investigators were able to match the patients on, inherently introducing confounding variables in this process. The ACS-NSQIP dataset was more extensive in documenting patient co-morbidities and complication rates in comparison to the SISS device data, which were provided by the instrumentation company, except for ACS-NSQIP data only tracking post-operative complications and re-operations for 30 days. Variables and patient characteristics that were not clearly defined in the SISS data set were subsequently not used for matching purposes. This included important factors such as operating room time, length of stay (LOS), and cost of index surgery. Through this process these researchers thoroughly analyzed, de-emphasized, and appropriately weighted variables from the SISS dataset that showed any signs of inconsistency in data gathering or recording in the attempt to limit inherent bias in the data collected by the manufacturer of the device. The cost of index surgery as well as subsequent revisions was not documented in either dataset and should be tracked and examined in future studies. Furthermore, this study was limited by a small sample size (n = 189 patients who received lumbar level SISSs). The authors stated that future studies should look to match a larger cohort of patients with controls based on more extensive demographic, co-morbidity factors, and spinal levels treated to achieve more reliable outcomes. Furthermore, the absence of patient-reported outcome scores limited the ability for evaluation of patient function and satisfaction with each procedure.

Aggarwal and Chow (2021) stated that LSS is a condition of progressive neurogenic claudication that can be managed with lumbar decompression surgery or less invasive interspinous process devices after failed conservative therapy. Popular interspinous process spacers include X-Stop, Vertiflex and Coflex, with X-Stop being taken off market due to its AEs profile. These researchers carried out a disproportionality analysis to examine if a statistically significant signal exists in the t3 interspinous spacers and the reported AEs using the Manufacturer and User Facility Device Experience (MAUDE) database maintained by the U.S. Food and Drug Administration (FDA). Statistically significant signals were found with each of the 3 interspinous spacer devices (Coflex, Vertiflex, and X-Stop) and each of the following AEs: fracture, migration, and pain/worsening symptoms. The authors concluded that further studies such as randomized controlled trials (RCTs) are needed to validate these findings.

These researchers stated that the medical device reports that were submitted to the FDA and posted on the MAUDE database were submitted by healthcare professionals and patients. Each and every AE may not be reported. Selection bias exists in that only the AEs reported were included in the analysis. The incidence or prevalence of an event could not be determined from this database. This analysis was carried out on the passive surveillance system of the MAUDE database. As such, direct comparisons could not be made between devices and AEs signals. Furthermore, analyses from the database could find statistically significant signals between a device and an AE but could not prove causality between them; RCTs would be needed to do that. However, X-Stop has been taken off the market so RCTs for it may not be available. Analysis of the medical device reports has advantages in identifying signals in real-world situations and in diverse populations, which is near impossible with the limited number of subjects used in the randomized clinical trials.

Piriformis Muscle Resection

Piriformis syndrome is believed to be a condition in which the piriformis muscle, a narrow muscle located in the buttocks, compresses or irritates the sciatic nerve. There is debate within the medical community whether this is a discrete condition, since it lacks objective evidence, and thus can not be reliably evaluated. Pain associated with piriformis syndrome is exacerbated in prolonged sitting. Specific physical findings are tenderness in the sciatic notch and buttock pain in flexion, adduction, and internal rotation of the hip. Imaging modalities are rarely helpful. Physical therapy is a mainstay of conservative treatment; and is usually enhanced by local injections (Papadopoulos and Khan, 2004). There is insufficient evidence regarding the effectiveness of resection of the piriformis muscle as a treatment for piriformis syndrome.

Endoscopic Laser Foraminoplasty

Endoscopic laser foraminoplasty (decompression) is primarily employed to treat patients with back pain caused by a prolapsed intervertebral disc. This endoscope-assisted laser technique is used to widen the lumbar exit route foramina in the spine. A laser is inserted to ablate portions of the intervertebral disc that have protruded. Hafez and associates (2001) noted that laser ablation of bone and ligament for nerve root decompression using the Ho: YAG laser may offer substantial advantages, but the risk of serious complication may only be avoided if the technique is combined with saline irrigation.

Knight and colleagues (2001) reported that the complication rate of endoscopic laser foraminoplasty is significantly lower than that reported following conventional spinal surgery. From these results, these investigators concluded that endoscopic laser foraminoplasty as a treatment for chronic LBP and sciatica presents less risk to a patient than conventional methods of spinal surgery. On the other hand, the National Institute for Clinical Excellence’s (2003) guidance on this procedure stated that current evidence on the safety and effectiveness of endoscopic laser foraminoplasty does not appear adequate to support the use of this procedure without special arrangements for consent and for audit or research. Moreover, the Specialist Advisors believed the effectiveness of this procedure to be unproven; and they also noted a number of potential complications including nerve injury and infection. Takeno et al (2006) stated that percutaneous lumbar disc decompression is associated with significant risk of disc, end-plate, and nerve root injuries, contrary to the general belief that the procedure is minimally invasive. Their findings highlight the need for careful diagnosis and sufficient technical skill when selecting percutaneous lumbar disc decompression as a treatment option.

Percutaneous Discectomy

Percutaneous disc decompression is a procedure specifically for a herniated disc in which the core of the disc has not broken through the disc wall. Performed through a needle in the skin, it is a form of surgery in which small bits of disc are removed to relieve pressure on the nerves surrounding the disc. The procedure may be performed with a cutting instrument or laser. Although the literature indicates that open laminectomy is an acceptable and, at times, necessary method of treatment for herniated intervertebral discs, percutaneous discectomy has emerged as a method of treatment for contained and non-migrated sequestered herniated discs. It has taken on 2 different forms: the selective removal of nucleus pulposus from the herniation site with various manual and automated instruments under endoscopic control (percutaneous nucleotomy with discoscopy, arthroscopic microdiscectomy, percutaneous endoscopic discectomy); the other is the removal of nucleus pulposus from the center of the disc space with one single automated instrument (automated percutaneous lumbar discectomy) to achieve an intradiscal decompression.

Automated percutaneous lumbar discectomy (APLD), or automated percutaneous mechanical lumbar discectomy, is another newer approach for surgical treatment of herniated discs. In this procedure, under local anesthesia and fluoroscopic guidance, a cannula is inserted into the disc; an automated cutting and aspiration device is then inserted through the cannula and the disc material is removed. As with the arthroscopic microdiscectomy/PED, APLD does not allow direct visualization of the disc or surrounding tissues. An example of a device used for this type of procedure includes, but may not be limited to, the Stryker Dekompressor Lumbar Discectomy Probe.

Automated percutaneous discectomy refers to techniques using minimal skin incisions (generally several, all less than 3 to 5 mm) to allow small instruments to be inserted, using radiography to visualize these instruments, and using extensions for the surgeon to reach the operative site without having to dissect tissues. Lasers to vaporize the nucleus pulposus have become an additional percutaneous option. Proponents of percutaneous lumbar discectomy cite several potential advantages over open discectomy procedures, including reduced morbidity, less potential for perineural scarring, less intra-operative blood loss, fewer complications of epidural fibrosis, transverse myelitis or disc space infection, reduced patient recovery times, and a faster return to normal activity. Initial case series focusing on lumbar disc disease reported encouraging results and the technique was widely adopted (Onik, 1990; Fiume et al, 1994; Ohnmeiss et al, 1994; Kotilainen and Valtonen, 1998). However, controlled trials reported less impressive results.

An interventional guidance on laser lumbar discectomy issued by the National Institute for Health and Clinical Excellence (NICE, 2003) stated that “Current evidence on the safety and efficacy of laser lumbar discectomy does not appear adequate to support the use of this procedure without special arrangements for consent and for audit or research”. The guidance noted that in an uncontrolled study of 348 patients with chronic back pain, 210 (60%) patients reported good or excellent results at 1 year, however, the validity of the studies on this procedure were compromised by high rates of loss to follow-up and the lack of long-term data on efficacy outcomes.

A review of minimally invasive procedures for disorders of the lumbar spine (Deen et al, 2003) stated that “Percutaneous lumbar diskectomy techniques hold considerable promise; however, lumbar microdiskectomy is the gold standard for surgical treatment of lumbar disk protrusion with radiculopathy”.

A National Institute for Health and Clinical Excellence (NICE, 2005) guidance on automated percutaneous mechanical lumbar discectomy stated that “Current evidence suggests that there are no major safety concerns associated with automated percutaneous mechanical lumbar discectomy. There is limited evidence of efficacy based on uncontrolled case series of heterogeneous groups of patients, but evidence from small randomised controlled trials shows conflicting results. In view of the uncertainties about the efficacy of the procedure, it should not be used without special arrangements for consent and for audit or research”.

A Cochrane review on surgical interventions for lumbar disc prolapse (Gibson and Waddell, 2007) examined the evidence on automated percutaneous discectomy and laser discectomy. The reviewers found four trials on automated percutaneous discectomy that met their inclusion criteria: 2 trials that compared automated percutaneous discectomy with chymopapain (Revel, 1993; Krugluger, 2000) and 2 that compared automated percutaneous discectomy with microdiscectomy (Chatterjee, 1995; Haines, 2002). The reviewers reported that the results from these 4 trials suggested that automated percutaneous discectomy produced inferior results to either more established procedure. The reviewers found 2 trials that met their inclusion criteria on laser discectomy: 1 trial compared the effects of a Nd-YAG-laser with that of a diode laser (Paul and Hellinger, 2000) and reported slight vaporization with both lasers and excellent shrinkage of disc tissue, however, no comparative outcome results were published; the other trial compared chemonucleolysis with laser discectomy (Steffen and Wittenberg, 1997) and reported that the study results favored chemonucleolysis. The reviewers concluded that while microdiscectomy gives broadly comparable results to open discectomy, the evidence on other minimally invasive techniques remains unclear (with the exception of chemonucleolysis using chymopapain, which is no longer widely available).

Nezer and Hermoni (2007) reviewed the evidence for percutaneous discectomy and percutaneous intradiscal radiofrequency thermocoagulation from 4 leading evidence-based databases: the National Institute for Clinical Excellence (NICE), which is an independent organization responsible for providing national guidance on treatments, the Cochrane Library, which is the largest library world-wide for systematic reviews and randomized controlled trials, the Center for Review and Dissemination at the University of York, which undertakes reviews of research about the effects of interventions in health and social care and finally, a search via Medline. The authors concluded that “The results from those systematic reviews and randomized trials show that, at present, unless or until better scientific evidence is available, automated percutaneous discectomy and laser discectomy should be regarded as research techniques”.

Goupille et al (2007) reviewed the literature on percutaneous laser disc decompression for treating lumbar disc herniation and stated that “[e]xperimental and clinical studies have investigated the modality of percutaneous laser disc decompression, but no consensus exists on the type of laser to use, the wavelength, duration of application, or appropriate energy applied. Studies have evaluated the impact of different techniques on the amount of disc removed, intradisc[al] pressure, and damage to neighboring tissue. Several open studies have been published, but their methodology and conclusions are questionable, and no controlled study has been performed”. The authors concluded that “Although the concept of laser disc nucleotomy is appealing, this treatment cannot be considered validated for disc herniation-associated radiculopathy resistant to medical treatment”.

A California Technology Assessment (2008) reviewed the scientific evidence for percutaneous laser disc decompression in the treatment of symptomatic lumbar disc herniation and found no published randomized, concurrently controlled, blinded trials comparing outcomes of percutaneous laser disc decompression with conventional conservative measures or open discectomy or laminectomy. The authors reported that the published articles concerning percutaneous laser disc decompression are almost all uncontrolled case series: 2 non-randomized comparative trials (Ohnmeiss et al, 1994, Tassi, 2006) and 1 systematic review (Boult et al, 2000) of percutaneous laser disc decompression have been published. The assessment stated that “The published data are not sufficient to conclude that the efficacy and safety of the percutaneous laser disc decompression procedure have been established in the investigational setting, let alone under conditions of usual medical practice. Percutaneous laser disc decompression requires further evaluation in a randomized controlled trial to assess its efficacy as an alternative treatment for symptomatic lumbar disc herniation”.

An assessment by the National Institute for Health and Clinical Excellence (NICE, 2008) of percutaneous endoscopic laser lumbar diskectomy concluded that “[c]urrent evidence on the safety and efficacy of percutaneous endoscopic laser lumbar discectomy is inadequate in quantity and quality. Therefore this procedure should only be used with special arrangements for clinical governance, consent, and audit or research”. The specialist advisors to NICE considered theoretical adverse events to include a higher risk of nerve or dural injury because of the poor visual field and disorientation, and a higher probability of missed fragments. One specialist advisor stated that there had been cases of heat damage to the cauda equine when laser was used for lumbar discectomy with concomitant foraminoplasty.

An assessment by NICE (2008) reached similar conclusions about the unproven status of percutaneous endoscopic laser cervical diskectomy. The NICE assessment concluded that “[c]urrent evidence on the safety and efficacy of percutaneous endoscopic laser cervical diskectomy is inadequate in quantity and quality. Available evidence reviewed by NICE was limited to uncontrolled case series”. The specialist advisors to NICE considered the most important theoretical risk of the procedure to be heat damage to nerve roots or to the spinal cord, potentially leading to quadriplegia. One specialist advisor stated that neurological damage had occurred in a patient as a result of using laser in the spine. The NICE review committee noted that the extent to which laser ablation was used instead of, or in addition to, mechanical methods of removing prolapsed disc material was unclear in much of the published evidence.

All of the trials reviewed above focused on lumbar disc herniation. There were no clinical trials of percutaneous discectomy of cervical or thoracic disc herniation.

Xclose™ Tissue Repair System

An annular (annulus) repair/closure may be performed following a spinal decompression (discectomy) surgery. It has been proposed that annular closure may reduce the risk of disc reherniation and the need for a fusion. Examples of devices used in an annular repair include the Inclose Surgical Mesh System and Xclose™ Tissue Repair System.

The Xclose™ Tissue Repair System (Anulex Technologies, Inc., Minnetonka, MN) has received 510(k) clearance for use in soft tissue approximation for procedures such as general and orthopedic surgery. It is being investigated as a method of soft tissue re-approximation of the anulus fibrosus after a lumbar discectomy procedure. However, there is insufficient evidence of the clinical effectiveness of the Xclose™ Tissue Repair System following a lumbar discectomy procedure. Randomized controlled studies are needed to determine whether closing the anulus following a lumbar discectomy procedure will result in improved clinical outcomes (i.e., decrease in re-herniation rates). To evaluate the benefits of anulus fibrosis repair utilizing the Xclose™ Tissue Repair system, Anulex is sponsoring a prospective, controlled, randomized study that will compare discectomy patients who receive anular repair using the Xclose™ Tissue Repair System to those who receive a standard discectomy without using the Xclose™. However, results from this study have not yet been published in the peer-reviewed medical literature.

Barricaid Annular Closure Device

An assessment of annulus fibrosus repair after lumbar discectomy by the Ludwig Boltzmann Institute for Heatlh Technology Assessment (Semlitsch & Geiger-Gritsch, 2019) found that the closure of anular defects after discectomy using the Barricaid device could be a meaningful intervention for a selected group of patients with a large anular defect to prevent reherniations and reoperations. However, a significant number of patients experienced problems with device integrity over a period of two years. In addition, these results are based on a few studies with a high risk of bias and published long-term results beyond a period of two years are missing. Similar results in terms of clinical effectiveness and safety were obtained for the Xclose™ system. However, only results from a single randomized controlled trial with a high risk of bias are available.

Thome et al (2018) noted that patients with large annular defects after lumbar discectomy for disc herniation are at high risk of symptomatic recurrence and re-operation. In a randomized, multi-center, superiority study, these investigators examined if a bone-anchored annular closure device (ACD), in addition to lumbar microdiscectomy, would result in lower re-herniation and re-operation rates plus increased overall success compared with lumbar microdiscectomy alone. Patients with symptoms of lumbar disc herniation for at least 6 weeks with a large annular defect (6 to 10 mm width) after lumbar microdiscectomy were enrolled in this trial. The co-primary endpoints determined a priori were recurrent herniation and a composite endpoint consisting of patient-reported, radiographic, and clinical outcomes. Study success required superiority of annular closure on both endpoints at 2-year follow-up. Patients received lumbar microdiscectomy with additional bone-anchored annular closure device (n = 276 participants) or lumbar microdiscectomy only (control; n = 278 participants). Among 554 randomized participants, 550 (annular closure device: n = 272; control: n = 278) were included in the modified intent-to-treat (ITT) effectiveness analysis and 550 (annular closure device: n = 267; control: n = 283) were included in the as-treated safety analysis. Both co-primary endpoints of the study were met, with recurrent herniation (50 % versus 70 %, p < 0.001) and composite endpoint success (27 % versus 18 %, p = 0.02) favoring annular closure device. The frequency of symptomatic re-herniation was lower with annular closure device (12 % versus 25 %, p < 0.001). There were 29 re-operations in 24 patients in the annular closure device group and 61 re-operations in 45 control patients. The frequency of re-operations to address recurrent herniation was 5 % with annular closure device and 13 % in controls (p = 0.001). End-plate changes were more prevalent in the annular closure device group (84 % versus 30 %, p < 0.001). Scores for back pain, leg pain, Oswestry Disability Index (ODI), and health-related quality of life (HR-QOL) at regular visits were comparable between groups over 2-year follow-up. The authors concluded that in patients at high-risk of herniation recurrence after lumbar microdiscectomy, annular closure with a bone-anchored implant reduced the risk of symptomatic recurrence and re-operation. Moreover, these researchers stated that additional study to determine outcomes beyond 2 years with a bone-anchored annular closure device is needed. This research was supported by Intrinsic Therapeutics. Two authors received study-specific support more than $10,000 per year, 8 authors received study-specific support less than $10,000 per year, and 11 authors received no study-specific support.

The authors stated that this study had several drawbacks. First, the findings of this study were not generalizable to all patients undergoing lumbar discectomy for disc herniation. Patients with inadequate disc height or small annular defects are not eligible for ACD implantation owing to surgical access challenges and likely would not benefit from preventative annular closure. Second, the authors noted the duration of follow-up in this study was limited. Third, the authors noted the possible influence of expectation bias that could not be ruled out as most patients and all surgeons were aware of treatment assignment. However, the authors stated, when comparing patient outcomes from sites where the principal investigator reported a financial relationship with the study sponsor versus those with no such relationship, there were no differences in study conclusions. The authors noted that this finding held true for the primary endpoint, re-herniation rates, re-operation rates, VAS scores, and ODI scores. The authors stated, furthermore, imaging studies were evaluated by independent radiologists. Additional limitations of this study included knowledge of treatment assignment by subjects and providers may have influenced decisions to re-operate. It should also be noted that the study did not find significant differences inpatient-centered outcomes including pain, ODI, VAS, or SF-36 scores.

Bouma, et al. (2019) conducted a secondary analysis of this randomized trial comparing lumbar discectomy with (n=272) vs without (n=278) implantation of a bone-anchored ACD. Among patients who received ACD implantation, 35 (13%) were blinded and 237 (87%) were unblinded to treatment allocation. In patients treated with ACD, propensity score-matching (1:1) was performed to account for imbalances in patient characteristics between blinded and unblinded groups. Key clinical outcomes were back pain severity (0-100 scale), leg pain severity (0-100 scale), Oswestry Disability Index (ODI, 0-100 scale), symptomatic reherniation, reoperation at the treated lumbar level, and device- or procedure-related serious adverse events (AEs). Outcomes were reported through 2 years of follow-up, which coincided with the time at which blinded patients were unblinded. The investigators found that there were no statistically significant differences in 2-year outcomes between propensity score-matched blinded (n=35) and unblinded (n=35) patients treated with the ACD. In blinded vs unblinded ACD patients compared to baseline, back pain severity decreased by 40 vs 37 points (P=0.61), leg pain severity decreased by 75 points in each group (P>0.99), and ODI decreased by 47 vs 43 points (P=0.19). The risks of symptomatic reherniation (5.7% vs 9.1%; P=0.59), reoperation (8.6% vs 12.2%, P=0.62), and device- or procedure-related serious AEs (5.7% vs 8.9%, P=0.63) were comparably low in blinded and unblinded patients. The investigators concluded that, in patients treated with lumbar discectomy and a bone-anchored ACD, there were no clinically important or statistically significant differences in back pain, leg pain, ODI, symptomatic reherniation, reoperation, or serious AEs over 2 years of follow-up whencomparing patients who were blinded vs unblinded to their treatment assignment.

The main limitations of this study were the small number of blinded subjects, the post hoc nature of the analysis, and the potential for bias due to surgeon awareness of treatment assignment. The small number of blinded subjects were treated among four sites, all in the same country; the authors stated that a larger sample distributed across more sites in different regions would provide a more robust sample for identifying the impact of patient blinding. The authors also observed that surgeons and outcome assessors were not blinded in this study, and that the independent effect of these potential biases on patient outcomes is unclear. The authors also noted that propensity score adjustment cannot account for unmeasured variables that may have influenced patient outcomes and, thus, are important sources of possible bias. The authors received financial support from Intrinsic Therapeutics.

In a randomized, multi-center trial, Nanda et al (2019) examined if implanting an annular closure device (ACD) following lumbar discectomy in patients with large defects in the annulus fibrosus lowers the risk of re-operation after 4 years. Patients with large annular defects following single-level lumbar discectomy were intra-operatively randomized to additionally receive an ACD or no treatment (controls). Clinical and imaging follow-up were performed at routine intervals over 4 years of follow-up. Main outcomes included re-operations at the treated lumbar level, leg pain scores on a visual analog scale (VAS), Oswestry Disability Index (ODI), and Physical Component Summary (PCS) and Mental Component Summary (MCS) scores from the SF-36 questionnaire. Among 550 patients (ACD 272, control 278), the risk of re-operation over 4 years was 14.4% with ACD and 21.1% with controls (p = 0.03). The reduction in re-operation risk with ACD was not significantly influenced by patient age (p = 0.51), sex (p = 0.34), body mass index (BMI; p = 0.21), smoking status (p = 0.85), level of herniation (p = 0.26), leg pain severity at baseline (p = 0.90), or ODI at baseline (p = 0.54). All patient-reported outcomes improved in each group from baseline to 4 years (all p < 0.001). The percentage of patients who achieved the minimal clinically important difference without a re-operation was proportionally higher in the ACD group compared to controls for leg pain (p = 0.07), ODI (p = 0.10), PCS (p = 0.02), and MCS (p = 0.06). The authors concluded that the addition of a bone-anchored ACD following lumbar discectomy in patients with large post-surgical annular defects reduced the risk of re-operation and provided better long-term pain and disability relief over 4 years compared to lumbar discectomy only.

The authors stated that this study had several drawbacks. First, the results presented were applicable only to patients with large post-discectomy annular defects, who accounted for approximately 30% of all lumbar discectomy cases. Implantation of an ACD in patients with small annular defects cannot be justified clinically given the inherently low risk of symptom recurrence in these individuals. Additional patient characteristics that were crucial to achieving positive results included adequate disc height and non-osteoporotic bone mineral density (BMD) of the lumbar spine. Second, the decision to re-operate involved shared decision-making between the patient and surgeon and, thus, there was potential for bias in the reported re-operation rates. Finally, 5-year follow- up in this study is ongoing and these long-term outcomes are anxiously awaited to provide final comparative efficacy, safety, and cost-utility results of bone-anchored ACD implantation.

Kienzler et al (2019) noted that a larger defect in the annulus fibrosus following lumbar discectomy is a well-known risk factor for re-herniation. Procedures intended to prevent re-herniation by sealing or occluding the annular defect warrant study in high-risk patients. In a randomized, multi-center study, these researchers examined the 3-year results of lumbar discectomy with a bone-anchored annular closure device (ACD) or lumbar discectomy only (controls) in patients at high-risk for re-herniation. Trial included patients with sciatica due to lumbar intervertebral disc herniation who failed conservative treatment. Patients with large annular defects after lumbar limited microdiscectomy were intra-operatively randomly assigned to receive ACD or control. Clinical and imaging follow-up was performed at routine intervals over 3 years. Main outcomes included rate of re-herniations, re-operations, and endplate changes; leg and back pain scores on a visual analog scale (VAS); Oswestry Disability Index (ODI); Physical Component Summary (PCS) and Mental Component Summary (MCS) scores from the SF-36; and adverse events (AEs) adjudicated by a data safety monitoring board. Among 554 randomized patients, the modified intent-to-treat (ITT) population consisted of 272 patients in which ACD implantation was attempted and 278 receiving control; device implantation was not attempted in 4 patients assigned to ACD. Outcomes at 3 years favored ACD for symptomatic re-herniation (14.8 % versus 29.5 %; p < 0.001), re-operation (11.0 % versus 19.3 %; p = 0.007), leg pain (21 versus 30; p < 0.01), back pain (23 versus 30; p = 0.01), ODI (18 versus 23; p = 0.02), PCS (47 versus 44; p < 0.01), and MCS (52 versus 49; p < 0.01). The frequency of all-cause serious AEs was comparable between groups (42.3 % versus 44.5 %; p = 0.61). The authors concluded that the addition of a bone-anchored ACD in patients with large annular defects following lumbar discectomy reduced the risk of re-herniation and re-operation; and had a similar safety profile over 3-year follow-up compared with lumbar limited discectomy only.

The authors stated that this study had several drawbacks. First, these findings were not applicable to all patients undergoing lumbar discectomy, but only the approximately 30 % of cases at high-risk of re-herniation due to a large post-surgical annular defect. The ACD is not intended to be used in patients with smaller defects since treatment with a permanent implant is difficult to justify in this population due to the relatively low risk of re-herniation. Second, lack of patient and outcome-assessor blinding to treatment allocation may have biased patient-reported outcomes or the decision to re-operate. Third, while CT imaging with core laboratory reading is a strength of this trial, it may also be perceived as a limitation since the application of CT findings to routine clinical practice is unclear. Finally, longer follow-up is needed in this younger patient population to determine the durability of effect with ACD and to ensure there are no concerning late-onset safety or device-related complications. While there was no association of vertebral endplate changes (VEPC) with clinical complications over 3 years among patients who received ACD, this should be confirmed in long-term follow-up. It should also be noted that some of the investigators (P. Klassen, L. Miller, R. Assaker, and C. Thome) reported consultancy with Intrinsic Therapeutics.

In a randomized, multi-center trial, Nanda et al (2019) examined if implanting an ACD following lumbar discectomy in patients with large defects in the annulus fibrosus lowers the risk of re-operation after 4 years. Patients with large annular defects following single-level lumbar discectomy were intra-operatively randomized to additionally receive an ACD or no treatment (controls). Clinical and imaging follow-up were performed at routine intervals over 4 years of follow-up. Main outcomes included re-operations at the treated lumbar level, leg pain scores on a VAS, ODI, PCS and MCS scores from the SF-36 questionnaire. Among 550 patients (ACD 272, control 278), the risk of re-operation over 4 years was 14.4 % with ACD and 21.1 % with controls (p = 0.03). The reduction in re-operation risk with ACD was not significantly influenced by patient age (p = 0.51), sex (p = 0.34), body mass index (BMI; p = 0.21), smoking status (p = 0.85), level of herniation (p = 0.26), leg pain severity at baseline (p = 0.90), or ODI at baseline (p = 0.54). All patient-reported outcomes improved in each group from baseline to 4 years (all p < 0.001). The percentage of patients who achieved the minimal clinically important difference without a re-operation was proportionally higher in the ACD group compared to controls for leg pain (p = 0.07), ODI (p = 0.10), PCS (p = 0.02), and MCS (p = 0.06) . The authors concluded that the addition of a bone-anchored ACD following lumbar discectomy in patients with large post-surgical annular defects reduced the risk of re-operation and provided better long-term pain and disability relief over 4 years compared to lumbar discectomy only.

The authors stated that this study had several drawbacks. First, the results presented were applicable only to patients with large post-discectomy annular defects, who accounted for approximately 30 % of all lumbar discectomy cases. Implantation of an ACD in patients with small annular defects could not be justified clinically given the inherently low risk of symptom recurrence in these individuals. Additional patient characteristics that were crucial to achieving positive results included adequate disc height and non-osteoporotic bone mineral density (BMD) of the lumbar spine. Second, the decision to re-operate involved shared decision-making between the patient and surgeon and; thus, there was potential for bias in the reported re-operation rates. Finally, 5-year follow- up in this study is ongoing and these long-term outcomes are anxiously awaited to provide final comparative efficacy, safety, and cost-utility results of bone-anchored ACD implantation. It should be noted that Mark P Arts reported consultancy with Intrinsic Therapeutics; personal fees from Zimmer-Biomet, EIT, and Silony, outside the submitted work; and receipt of royalties from EIT. Larry Miller reported consultancy with Intrinsic Therapeutics.

In a prospective RCT, Cho et al (2019) examined the effectiveness of a novel annular closure device (ACD) for preventing lumbar disc herniation (LDH) recurrence and re-operation compared with that of conventional lumbar discectomy (CLD). These researchers compared CLD with discectomy utilizing the Barricaid ACD. Primary radiologic outcomes included disc height, percentage of pre-operative disc height maintained, and re-herniation rates. Additional clinical outcomes included visual analog scale (VAS) scores for back and leg pain, Oswestry Disability Index (ODI) scores, and 12-item short-form health survey (SF-12) quality of life (QOL) scores. Outcomes were measured at pre-operation and at 1 week, 1, 3, 6, 12, and 24 months post-operation. A total of 60 patients (30 CLD, 30 ACD) were enrolled in this study. At 24-month follow-up, the disc height in the ACD group was significantly greater than that in the CLD group (11.4 ± 1.5 versus 10.2 ± 1.2 mm, p = 0.006). Re-herniation occurred in 1 patient in the ACD group versus 6 patients in the CLD group (χ2 = 4.04, p = 0.044). Back and leg VAS scores, ODI scores, and SF-12 scores improved significantly in both groups compared with pre-operative scores in the first 7 days following surgery and remained at significantly improved levels at a 24-month follow-up. However, no statistical difference was found between the 2 groups. The authors concluded that lumbar discectomy with the Barricaid ACD was more effective at maintaining disc height and preventing re-herniation compared with conventional discectomy. These researchers stated that these findings suggested that adoption of ACD in lumbar discectomy could help improve the treatment outcome.

The authors stated that this study had 2 main drawbacks. First, the 2-year follow-up, in which 70 % or fewer patients were actually followed-up, was short and limited the veracity with which conclusions could be applied in the long-term. However, it provided important early information regarding the stability and survivability of the device. These findings mirrored those of other investigators who examined this ACD and found that the device ensured maintenance of favorable clinical scores and lower rates of re-herniation. Second, the low sample size of this cohort (n = 30 in the ACD group) limited the ability to extrapolate results to larger populations.

Miller et al (2020) stated that patients with lumbar disc herniation and associated sciatica are often referred for lumbar discectomy. The surgical defect in the annulus fibrosus is typically left unrepaired after lumbar discectomy. Patients with large post-surgical annular defects (greater than or equal to 6 mm width) have a higher risk of symptom recurrence and re-operation compared to those with small defects. In these high-risk patients, a treatment gap exists due to the lack of effective treatments for durable annulus fibrosus repair. These investigators highlighted the therapeutic need and summarized the clinical results of a bone-anchored ACD (Barricaid) that was designed to fill the treatment gap in patients with large post-surgical annular defects. Clinical results were summarized by means of a systematic review with meta-analysis of 2 randomized and 2 non-randomized controlled studies. The authors stated that professional societal recommendations and clinical study results support the adoption of bone-anchored annular closure for use in properly selected patients undergoing lumbar discectomy who are at high-risk for re-herniation due to a large post-surgical defect in the annulus fibrosus. The risks of symptomatic re-herniation and re-operation were approximately 50 % lower in patients treated with lumbar discectomy and the Barricaid device compared to lumbar discectomy only, representing a clinically effective treatment strategy. Furthermore ,these researchers stated that stated that as more clinical study data continue to accrue demonstrating the positive long-term results of the Barricaid device, treatment of large defects in the annulus fibrosus during the index surgery may become the standard of care to prevent future symptomatic re-herniations and associated re-operations. It should be noted that this paper was funded by Intrinsic Therapeutics. L Miller has received personal fees from Intrinsic Therapeutics. One peer reviewer was a co-investigator in a randomized-controlled trial of the Barricaid device.

Kienzler et al (2021) noted that an ACD could potentially prevent recurrent herniation by blocking larger annular defects after limited microdiscectomy (LMD). In a non-comparative, single-center study, these researchers analyzed the incidence of endplate changes (EPC) and outcome after LMD with additional implantation of an ACD to prevent re-herniation. This analysis included data from a RCT study-arm of patients undergoing LMD with ACD implantation as well as additional patients undergoing ACD implantation at the authors’ institution. Clinical findings (VAS, ODI), radiological outcome (re-herniation, implant integrity, volume of EPC) and risk factors for EPC were assessed. A total of 72 patients (37 men, age of 47 ± 11.63 years) underwent LMD and ACD implantation between 2013 and 2016. A total of 71 (99 %) patients presented with some degree of EPC during the follow-up period (14.67 ± 4.77 months). In the multi-variate regression analysis, localization of the anchor was the only significant predictor of EPC (p = 0.038). The largest EPC measured 4.2 cm3. Re-herniation was documented in 17 (24 %) patients (symptomatic: n = 10; asymptomatic: n = 7); 6 (8.3 %) patients with symptomatic re-herniation underwent re-discectomy. Implant failure was documented in 19 (26.4 %) patients including anchor head breakage (n = 1, 1.3 %), dislocation of the whole device (n = 5, 6.9 %), and mesh dislocation into the spinal canal (n = 13, 18 %). Mesh subsidence within the EPC was documented in 15 (20.8 %) patients; 7 (9.7 %) patients underwent explantation of the entire, or parts of the device. The authors concluded that clinical improvement after LMD and ACD implantation was proven in this trial. High incidence and volume of EPC did not correlate with clinical outcome. The ACD might prevent disc re-herniation despite implant failure rates. Mechanical friction of the polymer mesh with the endplate was most likely the cause of EPC after ACD. Moreover, these researchers stated that long-term clinical and radiological assessments is needed to examine the consequences of these findings. These investigators stated that limitations of this study were the fact that this was a non-comparative, single-center study with a small patient cohort.

Peredo et al (2021) stated that recently, a number of implantable devices and techniques have been developed to prevent re‐herniation, yet these systems do not biologically repair the annulus fibrosus (AF). Examples of such systems include the AnchorKnot Tissue Approximation Kit (Anchor Orthopedics, Mississauga, ON, Canada) and Barricaid (Intrinsic Therapeutics, Inc., Woburn, MA). The AnchorKnot system enables minimally invasive visualization of the surgical field and is intended to minimize the removal of disc tissue and to close the AF defect with sutures. Although reports indicated the device has been used in multiple clinics, systematic evaluation of its safety and efficacy for disc repair is not yet available, apart from an in-vivo porcine study. The device is currently only indicated for visualization of the surgical field. In contrast, Barricaid obtained FDA approval in 2019 for the prevention of disc re‐herniation following a limited discectomy (4 to 6 mm tall and 6 to 12 mm wide lesion) in the lumbar spine. The device has a titanium body that is inserted into the adjacent vertebra and a polyester fabric mesh that is placed adjacent to the disc lesion following discectomy to prevent recurrent herniation. Several risks were identified following the long‐term implantation of the Barricaid device in a worst‐case baboon animal model study used to assess device safety. The study, reported in the summary of safety and effectiveness data FDA report, included implantation of the device at the L4 to L5 and L5 to L6 lumbar spine levels in 9 mature male baboons. Evidence of vertebral endplate disruption, device subsidence beyond the endplates, inflammation, fibrosis, osteolysis, and osteophyte formation was found after 12‐months of device implantation, suggesting there were multiple risks associated with the Barricaid device implantation. Since its FDA approval, early follow‐up clinical studies have reported beneficial outcomes 2 years post-implantation, such as the reduction in symptomatic disc re‐herniations and low complication rates; however, these reports also highlighted that device implantation led to higher prevalence of endplate changes. The long‐term safety and effectiveness of the device, especially concerning the damage of the vertebral bone and endplate during device fixation, remains to be determined.

In a secondary analysis of a multi-center randomized clinical study, Thome et al (2021) examined if a bone-anchored annular closure device in addition to lumbar microdiscectomy would result in lower re-herniation and re-operation rates versus lumbar microdiscectomy alone. This trial reported the 5-year follow-up for enrolled patients between December 2010 and October 2014 at 21 clinical sites. Patients in this study had a large annular defect (6 to 10 mm width) following lumbar microdiscectomy for treatment of lumbar disc herniation. Statistical analysis was performed from November to December 2020. Subjects were treated with lumbar microdiscectomy with additional bone-anchored annular closure device (device group) or lumbar microdiscectomy only (control group). Main outcomes and measures included the incidence of symptomatic re-herniation, re-operation, and AEs as well as changes in leg pain, ODI, and health-related QOL (HR-QOL) when comparing the device and control groups over 5 years of follow-up. Among 554 randomized subjects (mean [SD] age: 43 [11] years; 327 [59 %] were men), 550 were included in the modified ITT efficacy population (device group: n = 272; 270 [99 %] were White); control group: n = 278; 273 [98 %] were White) and 550 were included in the as-treated safety population (device group: n = 267; control group: n = 283). The risk of symptomatic re-herniation (18.8 % [SE, 2.5 %] versus 31.6 % [SE, 2.9 %]; p < 0.001) and re-operation (16.0 % [SE, 2.3 %] versus 22.6 % [SE, 2.6 %]; p = 0.03) was lower in the device group. There were 53 re-operations in 40 patients in the device group and 82 re-operations in 58 patients in the control group. Scores for leg pain severity, ODI, and HR-QOL significantly improved over 5 years of follow-up with no clinically relevant differences between groups. The frequency of serious AEs was comparable between the treatment groups. Serious AEs associated with the device or procedure were less frequent in the device group (12.0 % versus 20.5 %; difference, -8.5 %; 95 % CI: -14.6 % to -2.3 %; p = 0.008). The authors concluded that in patients who were at high risk of recurrent herniation following lumbar microdiscectomy owing to a large defect in the annulus fibrosus, this study’s findings suggested that annular closure with a bone-anchored implant lowered the risk of symptomatic recurrence and re-operation over a 5-year of follow-up period. These researchers stated that the findings of this study suggested that implantation with an annular closure device represented a safe and durable preventative strategy in patients at high risk for lumbar disc re-herniation following microdiscectomy.

The authors stated that this study had several drawbacks. First, the results were generalizable only to patients with large defects in the annulus fibrosus following lumbar discectomy. Second, most patients and all investigators were aware of treatment assignment; thus, it was possible that re-operation rates may have been influenced by performance bias. Third, patients in the trial were treated with limited lumbar discectomy with little to no removal of disc material within the intervertebral space. It was possible that lower re-herniation rates could be achieved with aggressive disc resection, although intervertebral instability and spondylosis progression were potential risks with this surgical technique. Fourth, although end-plate changes in the device group were associated with a benign clinical course through 5 years of follow-up, their natural history over longer term follow-up is currently unclear. Finally, although the 5-year follow-up visit rate of 73 % was typical of long-term clinical trials of spinal devices, the potential for bias owing to missing data must be acknowledged.

In a meta-analysis, Wang et al (2023) examined the safety and effectiveness of the various annular defect repair methods that have emerged in recent years. These investigators carried out a meta-analysis of randomized controlled trials (RCTs) and non-RCTs. Studies from PubMed, Embase, and the Cochrane Library (CENTRAL) on lumbar disc herniation (LDH) treatment with annular repair published from inception to April 2, 2022 were included. They summarized the safety and effectiveness of annular repair techniques based on a random-effects model meta-analysis. A total of 7 RCTs and 8 observational studies with a total of 2,161 subjects met the inclusion criteria. The pooled data analysis showed that adding the annular repair technique reduced post-operative recurrence rate, re-operation rate, and loss of inter-vertebral height compared with lumbar discectomy alone. Subgroup analysis based on different annular repair techniques showed that the Barricaid Annular Closure Device (ACD) was effective in preventing re-protrusion and reducing re-operation rates, while there was no significant difference between the other subgroups. The annulus fibrosus suture (AFS) did not improve the post-operative Oswestry Disability Index (ODI). No statistically significant difference was observed in the incidence of adverse events (AEs) between the annular repair and control groups. The authors concluded that lumbar discectomy combined with ACD can effectively reduce the post-operative recurrence and re-operation rates in patients with LDH. AFS alone was less effective in reducing recurrence and re-operation rates and did not improve post-operative pain and function. Annular repair may help maintain post-operative disc height; moreover, these researchers stated that further studies are needed to confirm this finding. Currently, biomaterials lack application value but can improve post-operative pain and function. Combining them with AFS may be an adequate alternative at this stage; further studies are needed to confirm these findings. The authors noted that all current annular repair technologies are safe, and biomaterials with better performance will be the main direction of future development.

The authors stated that this meta-analysis had several drawbacks. First, due to the current level of technical development and research, there is a lack of high-quality RCTs. These researchers included randomized controlled and observational studies, which may reduce the level of evidence of this study. Second, some confounding factors, including BMI and the male-to-female ratio, were not sufficiently reported in some studies. Similarly, there was a high degree of heterogeneity in some of the pooled results, and these investigators were unable to identify the source of heterogeneity. Moreover, due to a lack of adequate literature and large heterogeneity, the authors were unable to further examine some comprehensive results for the subgroup analysis based on annular repair. Finally, as for the possible differences between studies, these researchers did not perform a net meta-analysis to further compare the advantages and disadvantages of different interventions.

Nunley et al (2023) noted that re-herniation rates following lumbar discectomy are low for most patients; however, patients with a large defect in the annulus fibrosis have a significantly higher risk of recurrence. Previous results from a RCT showed that the implantation of a bone-anchored ACD during discectomy surgery lowered the risk of symptomatic re-herniation and re-operation over 1 year with fewer serious AEs (SAEs) compared to discectomy alone. In a prospective, post-market, historically controlled, single-arm study, these researchers examined the use of an ACD during discectomy, and to confirm the results of the RCT that was used to establish regulatory approval in the U.S. In this post-market study, all patients (n = 55) received discectomy surgery with a bone-anchored ACD. The comparison population was patients enrolled in the RCT study who had discectomy with an ACD (n = 262) or discectomy alone (n = 272). All other eligibility criteria, surgical technique, device characteristics, and follow-up methodology were comparable between studies. Endpoints included rate of symptomatic re-herniation or re-operation, SAEs, and patient-reported outcome measures (PROMs) of disability, pain, and QOL. A total of 55 patients received ACD implants at 12 sites between May 2020 and February 2021. I n the previous RCT, 272 control patients had discectomy surgery alone (RCT-Control), and 262 patients had discectomy surgery with an ACD implant (RCT-ACD). Baseline characteristics across groups were typical of the overall population undergoing lumbar discectomy. The proportion of patients who experienced re-herniation and/or re-operation was significantly lower in the ACD group compared to RCT-ACD and RCT-Control groups (p < 0.05). In the ACD study, the 1-year rate of symptomatic re-herniation was 3.7 %, compared to 8.5 % in the RCT-ACD group and 17.0 % in the RCT-Control group. In the ACD group, the risk of re-operation was 5.5 %, compared to 6.5 % in the RCT-ACD group and 12.5 % in the RCT-Control group. There were no device-related SAEs or device integrity failures in the ACD, and there were clinically meaningful improvements in PROMs of disability, pain, and QOL. The authors concluded that in this post-market study of bone-anchored ACD in patients with large annular defects, rates of symptomatic re-herniation, re-operation, and SAEs were all low. Compared to the RCT, the post-market ACD study showed lower rates of re-herniation and/or re-operation and measures of back pain 1-year post-surgery.

The authors stated that this study had several drawbacks. First, PROMs measured at prospectively defined time-points had the potential to miss acute episodes of a re-herniation or re-operation. Second, the single-arm design of this post-market study limited the direct comparison to a control group; however, there are no direct clinical alternatives to the implantation of this ACD to use for comparison in the study, as currently, it is the only FDA-approved method of annular closure. Third, a greater number of patients in the post-market study had larger annular defect widths, as compared to the RCT study; however, this was largely due to pre-operative screening in the post-market study being selectively more sensitive for large defects. This could also be considered a potential strength of the study, as these patients had comparable or better outcomes than those in the RCT study. Fourth, this study was not powered to determine the non-inferiority of outcomes comparing data in the post-market study to the RCT study; however, study design elements and methodology were similar between the post-market and RCT studies, including eligibility criteria, surgical technique, and follow-up. The authors stated that, despite the small study size and the single-arm design, the data presented provide evidence that ACD implantation yielded comparable results in multiple settings.

Ying et al (2023) stated that the intervertebral disc (IVD) is a load-bearing, avascular tissue that cushions pressure and increases flexibility in the spine. Under the influence of obesity, injury, and reduced nutrient supply, it develops pathological changes such as fibular annulus (AF) injury, disc herniation, and inflammation, eventually leading to intervertebral disc degeneration (IDD). Lower back pain (LBP) caused by IDD is a severe chronic disorder that severely affects patients’ QOL and has a substantial socioeconomic impact. Patients may consider surgical intervention after conservative treatment has failed; however, the broken AF could not be repaired after surgery, and the incidence of re-protrusion and reoccurring pain is high, possibly leading to a degeneration of the adjacent vertebrae; thus, effective treatment strategies must be examined to repair and prevent IDD. These researchers noted that in recent years, AF suture repair of IVD has been performed in clinical practice and has shown promising results. The currently marketed available devices include Beijing 2020 Medical Science & Technology’s Disposable AF Suture Devices (EFIT-I-II-III-IV-V, ELAS-A, SMILE, STAR), the Xclose Tissue Repair System, the AnchorKnot Suture-Passing Device, and the Barricaid ACD.

McClure et al (2024) reported the underlying cause of local inflammation causing recurrent neuropathy and multiple operations in a patient with a Barricaid device. After removal of this patient’s Barricaid device, these researchers sent local inflammatory tissue to pathology for histochemical analysis. Upon discovery of giant cells formation with polarizable foreign bodies, these investigators performed a literature review regarding the Barricaid device and its elements. After 2 previous operations and 3 trials of conservative management, the presented patient underwent an L5/S1 TLIF with removal of her previously installed Barricaid device. There were no signs of device instability/failure nor were there obvious signs of infection. Inflamed tissue proximal to the Barricaid device was discovered, debrided, and sample sent to pathology. Removal of the Barricaid device resulted in subsequent and durable relief of her symptoms. During review of this case, these researchers discovered the polyethylene terephthalate (PET) weave used in the Barricaid device is known to induce foreign body reactions, and this precise finding was observed in the majority of animal data submitted to the FDA for the device’s acceptance. The authors stated that given the constellation of this patient’s symptoms, imaging, intra-operative, and pathology findings, previously published reports, and pre-approval data submitted to the FDA, these investigators concluded that the inflammatory response to the PET weave in this patient’s Barricaid device was the ultimate cause of her continued neuropathy despite multiple prior surgical interventions.

Wang et al (2024) examined the safety and effectiveness of the various annular defect repair methods that have emerged in recent years. These investigators carried out a meta-analysis of RCTs and non-RCTs. Studies from PubMed, Embase, and the Cochrane Library (CENTRAL) on lumbar disc herniation treatment with annular repair published from inception to April 2, 2022 were included. They summarized the results of annular repair techniques based on a random-effects model meta-analysis. A total of 7 RCTs and 8 observational studies with a total of 2,161 participants met the inclusion criteria. The pooled data analysis showed that adding the annular repair technique reduced post-operative recurrence rate, re-operation rate, and loss of intervertebral height compared with lumbar discectomy alone. Subgroup analysis based on different annular repair techniques showed that the Barricaid ACD was effective in preventing re-protrusion and reducing re-operation rates, while there was no significant difference between the other subgroups. The annulus fibrosus suture (AFS) did not improve the post-operative ODI. No statistically significant difference was observed in the incidence of AEs between the annular repair and control groups. The authors concluded that lumbar discectomy combined with ACD could lower the post-operative recurrence and re-operation rates in patients with LDH. AFS alone was less effective in reducing recurrence and re-operation rates and did not improve post-operative pain and function. Annular repair may help maintain post-operative disc height; further studies to confirm this are needed. Currently, biomaterials lack application value but could improve post-operative pain and function. Combining them with AFS may be an adequate alternative at this stage; further studies to confirm these findings are needed. All current annular repair technologies are safe, and biomaterials with better performance will be the main direction of future development.

The authors stated that this meta-analysis had several drawbacks. First, due to the current level of technical development and research, there is a lack of high-quality RCTs. These researchers included RCTs and observational studies, which may reduce the level of evidence of this study. Second, some confounding factors, including BMI and the male-to-female ratio, were not sufficiently reported in some studies. Similarly, there was a high degree of heterogeneity in some of the pooled results, and these investigators were unable to identify the source of heterogeneity. Third, owing to a lack of adequate literature and large heterogeneity, they were unable to further examine some comprehensive results for the subgroup analysis based on annular repair. Fourth, as for the possible differences between studies, the authors did not carry out a net meta-analysis to further compare the advantages and disadvantages of different interventions.

Radiofrequency Denervation for Sacroiliac Joint Pain

Cohen et al (2008) carried out a randomized placebo-controlled study in 28 patients with injection-diagnosed sacroiliac joint pain. Fourteen patients received L4 to L5 primary dorsal rami and S1 to S3 lateral branch radiofrequency (RF) denervation using cooling-probe technology after a local anesthetic block, and 14 patients received the local anesthetic block followed by placebo denervation. Patients who did not respond to placebo injections crossed-over and were treated with RF denervation using conventional technology. One, 3, and 6 months after the procedure, 11 (79%), 9 (64%), and 8 (57%) RF-treated patients experienced pain relief of 50% or greater and significant functional improvement. In contrast, only 2 patients (14%) in the placebo group experienced significant improvement at their 1-month follow-up, and none experienced benefit 3 months after the procedure. In the cross-over group (n = 11), 7 (64%), 6 (55%), and 4 (36%) experienced improvement 1, 3, and 6 months after the procedure. One year after treatment, only 2 patients (14%) in the treatment group continued to demonstrate persistent pain relief. The authors concluded that these results provide preliminary evidence that L4 and L5 primary dorsal rami and S1-S3 lateral branch RF denervation may provide intermediate-term pain relief and functional benefit in selected patients with suspected sacroiliac joint pain. They stated that larger, multi-centered studies with long-term follow-up and comprehensive outcome measures are needed to confirm these results, further establish safety and determine the optimal candidates and treatment parameters.

Drawbacks of this study, albeit a randomized controlled one, include small number of patients as well as “poor” long-term results (only 14% in the treatment group showed continued pain relief after 1 year). In addition, a systematic review on sacroiliac joint interventions (Hansen et al, 2007) concluded that the evidence for RF neurotomy in managing chronic sacroiliac joint pain is limited.

In an observational study, Karaman et al (2011) examined the safety and effectiveness of novel cooled RF application for sacral lateral-branch denervation. Patients experiencing chronic sacroiliac pain were selected for this study. Fluoroscopy guidance cooled RF denervation was applied on the L5 dorsal ramus and the S1 to S3 lateral branches on patients who had twice undergone consecutive joint blockages to confirm the diagnosis and obtained at least 75% pain relief. At the 1st, 3rd and 6th month post-operatively, the patients’ pain was evaluated using a VAS, and their physical function was evaluated with the ODI. Cooled RF was applied on a total of 15 patients. Prior to the procedures, the median VAS score (interquartile range) was 8 (7 to 9), but at the 1st, 3rd and 6th month, this had fallen to 3 (1 to 4), 2 (1 to 3) and 3 (2 to 4). The baseline median ODI score (interquartile range) was 36 (32 to 38), while at the 1st, 3rd and 6th month, it was 16 (8 to 20), 12 (9 to 18) and 14 (10 to 20), respectively. At the final control, while 80% of the patients reported at least a 50% decline in pain scores, 86.7% of those reported at least a 10-point reduction in ODI scores. The authors concluded that the cooled RF used for sacroiliac denervation was an effective and safe method in the short-to-intermediate term. The major drawbacks of this study were its small sample size (n = 15) and short follow-up period (6 months). The authors stated that RCTs with longer follow=up period are needed.

Stelzer et al (2013) retrospectively evaluated the use of cooled RF lateral branch neurotomy (LBN) to treat chronic SIJ-mediated LBP in a large European study population. The electronic records of 126 patients with chronic LBP who underwent treatment with cooled RF LBN were identified. Subjects were selected for treatment based on physical examination and positive response (greater than or equal to 50% pain relief) to an intra-articular SIJ block. Cooled RF LBN involved lesioning the L5 dorsal ramus and lateral to the S1, S2, and S3 posterior sacral foraminal apertures. Visual analog scale pain scores, quality of life, medication usage, and satisfaction were collected before the procedure, at 3 to 4 weeks post-procedure (n = 97), and once again between 4 and 20 months post-procedure (n = 105). When stratified by time to final follow-up (4 to 6, 6 to 12, and greater than 12 months, respectively): 86%, 71%, and 48% of subjects experienced greater than or equal to 50% reduction in VAS pain scores, 96%, 93%, and 85% reported their quality of life as much improved or improved, and 100%, 62%, and 67% of opioid users stopped or decreased use of opioids. The authors concluded that the current results showed promising, durable improvements in pain, quality of life, and medication usage in a large European study population, with benefits persisting in some subjects at 20 months after treatment. The main drawbacks of this study were its retrospective nature, lack of a control group, difficulty in contacting certain subjects, missing data for some subjects, as well as variable length of time to final follow-up.

Ho and colleagues (2013) noted that SIJ pain is a common cause of chronic LBP. Different techniques for RF denervation of the SIJ have been used to treat this condition. However, results have been inconsistent because the variable sensory supply to the SIJ is difficult to disrupt completely using conventional RF. Cooled RF is a novel technique that uses internally cooled RF probes to enlarge lesion size, thereby increasing the chance of completely denervating the SIJ. These researchers evaluated the effectiveness of cooled RF denervation using the SInergy™ cooled RF system for SIJ pain. The charts of 20 patients with chronic SIJ pain who had undergone denervation using the SInergy™ cooled RF system were reviewed at 2 years following the procedure. Outcome measures included the Numeric Rating Scale for pain intensity, Patient Global Impression of Change, and Global Perceived Effect for patient satisfaction. Fifteen of 20 patients showed a significant reduction in pain (a decrease of at least 3 points on the Numeric Rating Scale). Mean Numeric Rating Scale for pain decreased from 7.4 ± 1.4 to 3.1 ± 2.5, mean Patient Global Impression of Change was “improved” (1.4 ± 1.5), and Global Perceived Effect was reported to be positive in 16 patients at 2 years following the procedure. The authors concluded

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Table Of Contents

Policy

Scope of Policy

Medical Necessity

Facet joint injections

Trigger point injections

Sacroiliac joint injections

Interlaminar epidural injections

Non-pulsed radiofrequency facet denervation

Spinal Fixation

Intervertebral body fusion devices

Percutaneous polymethylmethacrylate vertebroplasty (PPV), kyphoplasty, or Spinejack System

Lateral (including extreme [XLIF], extra and direct lateral [DLIF]) interbody fusion

Coccygectomy

Vertebral body replacement spacers

Minimally invasive transforaminal lumbar interbody fusion with direct visualization

Cementoplasty

Sacroiliac joint fusion

Intramuscular or intravenous injection of ketorolac tromethamine (Toradol)

The Spinal System-X (Corus)

Experimental, Investigational, or Unproven

Policy Limitations and Exclusions

Laser:

Microscope and endoscope:

Related CMS Coverage Guidance

Code of Federal Regulations (CFR):

Internet-Only Manual (IOM) Citations:

Medicare Coverage Determinations:

Related Policies

CPT Codes /HCPCS Codes/ICD-10 Codes

Coccygectomy:

CPT codes covered if selection criteria are met:

ICD-10 codes covered if selection criteria are met:

Facet joint injections [not covered for intradiscal and/or paravertebral oxygen/ozone injection]:

CPT codes covered if selection criteria are met:

CPT codes not covered for indications listed in the CPB:

Other CPT codes related to the CPB:

Other HCPCS codes related to the CPB:

ICD-10 codes covered if selection criteria are met:

ICD-10 codes not covered for indications listed in the CPB:

Ganglion Nerve Block:

CPT codes not covered for indications listed in the CPB:

ICD-10 codes not covered for indications listed in the CPB:

Trigger point Injections:

CPT codes covered if selection criteria are met:

CPT codes not covered for indications listed in the CPB:

Other CPT codes related to the CPB:

Other HCPCS codes related to the CPB:

ICD-10 codes covered if selection criteria are met:

ICD-10 codes not covered for indications listed in the CPB:

Sacroiliac joint injections:

CPT codes covered if selection criteria are met:

CPT codes not covered for indications listed in the CPB:

Other CPT codes related to the CPB:

HCPCS codes covered if selection criteria are met:

Other HCPCS codes related to the CPB:

ICD-10 codes covered if selection criteria are met:

ICD-10 codes not covered for indications listed in the CPB:

Epidural injections of corticosteroid preparations:

CPT codes covered if selection criteria are met:

Other CPT codes related to the CPB:

Other HCPCS codes related to the CPB:

ICD-10 codes covered if selection criteria are met:

ICD-10 codes not covered for indications listed in the CPB:

Chymopapain chemonucleolysis:

CPT codes covered if selection criteria are met:

Other CPT codes related to the CPB:

ICD-10 codes not covered for indications listed in the CPB:

Percutaneous lumbar discectomy or laser-assisted disc decompression (LADD):

CPT codes not covered if selection criteria are met:

Other CPT codes related to the CPB:

HCPCS codes not covered for indications listed in the CPB:

Other HCPCS codes related to the CPB:

ICD-10 codes not covered if selection criteria are met::

Minimally Invasive Lumbar Decompression (MILD):

CPT codes not covered for indications listed in the CPB:

Radiofrequency facet denervation:

CPT codes covered if selection criteria are met:

CPT codes not covered for indications listed in the CPB:

Other CPT codes related to the CPB: