Latest Review Date: May 2024

Category:  Surgery                                                               

POLICY:

Interspinous or interlaminar distraction devices as a stand-alone procedure are considered investigational as a treatment of spinal stenosis.

Use of an interlaminar stabilization device following decompression surgery is considered investigational.

DESCRIPTION OF PROCEDURE OR SERVICE:

Interspinous and interlaminar implants (spacers) stabilize or distract the adjacent lamina and/or spinous processes and restrict extension to reduce pain in patients with lumbar spinal stenosis and neurogenic claudication. Interspinous spacers are small devices implanted between the vertebral spinous processes. After implantation, the device is opened or expanded to distract (open) the neural foramen and decompress the nerves. Interlaminar spacers are implanted midline between adjacent lamina and spinous processes to provide dynamic stabilization either following decompressive surgery or as an alternative to decompressive surgery.

Spinal Stenosis

Lumbar spinal stenosis, which affects over 200,000 people in the United States (U.S.), involves a narrowed central spinal canal, lateral spinal recesses, and/or neural foramina, resulting in pain as well as limitation of activities such as walking, traveling, and standing. In adults over 60 in the U.S., spondylosis (degenerative arthritis affecting the spine) is the most common cause. The primary symptom of lumbar spinal stenosis is neurogenic claudication with back and leg pain, sensory loss, and weakness in the legs. Symptoms are typically exacerbated by standing or walking and relieved with sitting or flexion at the waist.

Some sources describe the course of LSS as “progressive” or “degenerative,” implying that neurologic decline is the usual course. Longer term data from the control groups of clinical trials as well as from observational studies suggest that, over time, most patients remain stable, some improve, and some deteriorate.

The lack of a valid classification for LSS contributes to wide practice variation and uncertainty about who should be treated surgically and which surgical procedure is best for each patient. This uncertainty also complicates research on spinal stenosis, particularly the selection of appropriate eligibility criteria and comparators.

Treatment

Appropriate surgical treatments for patients with spinal stenosis not responding to conservative treatments include decompression with or without spinal fusion. There are many types of decompression surgery and types of fusion operations. In general, spinal fusion is associated with more complications and a longer recovery period and, in the past, was generally reserved for patients with spinal deformity or moderate grade spondylolisthesis.

Conservative treatment for spinal stenosis may include physical therapy, pharmacotherapy, epidural steroid injections, and many other modalities. The terms “nonsurgical” and “nonoperative” have also been used to describe conservative treatment. Professional societies recommend that surgery for LSS should be considered only after a patient fails to respond to conservative treatment, but there is no agreement about what constitutes an adequate course or duration of treatment.

The term “conservative management” may refer to “usual care” or to specific programs of nonoperative treatment, which use defined protocols for the components and intensity of conservative treatments, often in the context of an organized program of coordinated, multidisciplinary care. The distinction is important in defining what constitutes a failure of conservative treatment and what comparators should be used in trials of surgical vs nonsurgical management. The rationale for surgical treatment of symptomatic spinal stenosis rests on the Spine Patient Outcomes Research Trial (SPORT), which found that patients who underwent surgery for spinal stenosis and spondylolisthesis had better outcomes than those treated nonoperatively. The SPORT investigators did not require a specified program of nonoperative care but rather let each site decide what to offer. A subgroup analysis of the SPORT trial found that only 37% of nonsurgically treated patients received physical therapy in the first 6 weeks of the trial and that those who received physical therapy before 6 weeks had better functional outcomes and were less likely to cross over to surgery later. These findings provide some support for the view that, in clinical trials, patients who did not have surgery may have had suboptimal treatment, which can lead to a larger difference favoring surgery. The SPORT investigators asserted that their nonoperative outcomes represented typical results at a multidisciplinary spine center at the time, but recommended that future studies compare the efficacy of specific nonoperative programs to surgery.

A trial by Delitto et al (2015) compared surgical decompression with a specific therapy program emphasizing physical therapy and exercise. Patients with lumbar spinal stenosis and from 0 to 5 mm of slippage (spondylolisthesis) who were willing to be randomized to decompression surgery versus an intensive, organized program of nonsurgical therapy were eligible. Oswestry Disability Index scores were comparable to those in the SPORT trial. A high proportion of patients assigned to nonsurgical care (57%) crossed over to surgery (in SPORT the proportion was 43%), but crossover from surgery to nonsurgical care was minimal. When analyzed by treatment assignment, Oswestry Disability Index scores were similar in the surgical and nonsurgical groups after 2 years of follow-up. The main implication is that about one-third of patients who were deemed candidates for decompression surgery but instead entered an intensive program of conservative care achieved outcomes similar to those of a successful decompression.

Diagnostic criteria for fusion surgery are challenging because patients without spondylolisthesis and those with grade 1 spondylolisthesis are equally likely to have predominant back pain or predominant leg pain. The SPORT trial did not provide guidance on which surgery is appropriate for patients who do not have spondylolisthesis, because nearly all patients with spondylolisthesis underwent fusion whereas nearly all those who did not have spondylolisthesis underwent decompression alone. In general, patients with predominant back pain have more severe symptoms, worse function, and less improvement with surgery (with or without fusion). Moreover, because back pain improved to the same degree for the fused spondylolisthesis patients as for the unfused spinal stenosis patients at 2 years, the SPORT investigators concluded that it was unlikely that fusion led to the better surgical outcomes in patients with spondylolisthesis than those with no spondylolisthesis.

Throughout the 2000s, decompression plus fusion became more widely used until, in 2011, it surpassed decompression alone as a surgical treatment for spinal stenosis. However, in 2016, findings from two randomized trials of decompression alone vs decompression plus fusion were published. The Swedish Spinal Stenosis Study (SSSS) found no benefit of fusion plus decompression compared with decompression alone in patients who had spinal stenosis with or without degenerative spondylolisthesis. The Spinal Laminectomy versus Instrumented Pedicle Screw (SLIP) trial found a small but clinically meaningful improvement in the Physical Component Summary score of the 36-Item Short-Form Health Survey but no change in Oswestry Disability Index scores at 2, 3, and 4 years in patients who had spinal stenosis with grade 1 spondylolisthesis (3-14 mm).The patients in SLIP who had laminectomy alone had higher reoperation rates than those in SSSS, and the patients who underwent fusion had better outcomes in SLIP than in SSSS. While some interpret the studies to reflect differences in patient factors-in particular, SSSS but not SLIP included patients with no spondylolisthesis, the discrepancy may also be influenced by factors such as time of follow-up or national practice patterns. As Pearson (2016) noted, it might have been helpful to have patient-reported outcome data on the patients before and after reoperation, to see whether the threshold for reoperation differed in the 2 settings. A small trial conducted in Japan, Inose et al (2018) found no difference in patient-reported outcomes between laminectomy alone and laminectomy plus posterolateral fusion in patients with 1-level spinal stenosis and grade 1 spondylolisthesis; about 40% of the patients also had dynamic instability. Certainty in the findings of this trial is limited because of its size and methodologic flaws.

Spacer Devices

Investigators have sought less invasive ways to stabilize the spine and reduce the pressure on affected nerve roots, including interspinous and interlaminar implants (spacers). These devices stabilize or distract the adjacent lamina and/or spinous processes and restrict extension in patients with lumbar spinal stenosis and neurogenic claudication.

Other types of dynamic posterior stabilization devices are pedicle screw/rod-based devices and total facet replacement systems; they are not discussed in this policy.

Interspinous Implants

Interspinous spacers are small devices implanted between the vertebral spinous processes. After implantation, the device is opened or expanded to distract the neural foramina and decompress the nerves. One type of interspinous implant is inserted between the spinous processes through a small (4-8 cm) incision and acts as a spacer between the spinous processes, maintaining flexion of that spinal interspace. The supraspinous ligament is maintained and assists in holding the implant in place. The surgery does not include any laminotomy, laminectomy, or foraminotomy at the time of insertion, thus reducing the risk of epidural scarring and cerebrospinal fluid leakage. Other interspinous spacers require removal of the interspinous ligament and are secured around the upper and lower spinous processes.

Interlaminar Spacers

Interlaminar spacers are implanted midline between adjacent lamina and spinous processes to provide dynamic stabilization either following decompression surgery or as an alternative to decompression surgery. Interlaminar spacers have 2 sets of wings placed around the inferior and superior spinous processes. They may also be referred to as interspinous U. These implants aim to restrict painful motion while enabling normal motion. The devices (spacers) distract the laminar space and/or spinous processes and restrict extension. This procedure theoretically enlarges the neural foramen and decompresses the cauda equina in patients with spinal stenosis and neurogenic claudication.  

KEY POINTS:

The most recent literature search was performed through February 28, 2024.

Summary of Evidence

For individuals who have spinal stenosis and no spondylolisthesis or grade 1 spondylolisthesis who receive an interspinous or interlaminar spacer as a stand-alone procedure, the evidence includes 1 systematic review of randomized controlled trials (RCTs) of X-STOP spacer devices (which is no longer marketed) or other devices not approved in the US, observational retrospective claims data analyses, and 2 RCTs of 2 spacers compared to each other (Superion Indirect Decompression System, coflex interlaminar implant). The relevant outcomes are symptoms, functional outcomes, quality of life (QOL), and treatment-related morbidity. Overall, the use of interspinous or interlaminar distraction devices (spacers) as an alternative to spinal decompression has shown high failure and complication rates. A systematic review of RCTs comparing interspinous spacer devices (ISDs) and decompression surgery in patients with lumbar spinal stenosis found that ISD resulted in an increased rate of reoperation compared to decompression, as well as no statistically significant differences in pain, functional, and quality of life outcomes. Additional longitudinal retrospective comparative claims analyses found that there was a significantly lower rate of reoperation in patients with lumbar spinal stenosis who received ISD compared to open surgery. However, there are many limitations inherent to claims analyses, including the possibility of coding or data entry errors and the omission of clinical details not needed to justify payment. For example, diagnosis codes identified in claims data lack clinical context, such as the severity of lumbar spinal stenosis or postoperative complications, as well as other prior therapies. Claims data also does not capture patient-reported outcomes, such as visual analog scale scores or Zurich Claudication Questionnaire scores, limiting the ability to determine true efficacy. It is unknown if authors were able to see when a patient was lost to follow-up due to death or end of Medicare coverage, as these rates were not reported. Additionally, in 1 of the studies, since the baseline characteristics of patients receiving ISD indicated that these patients may be inherently sicker than those receiving open surgery, we need clinical context to infer if the reason they did not receive additional surgical procedures post initial ISD placement is because they truly didn't require intervention, or they were too sick to tolerate the procedure. While claims data gives us some information related to re-operation rates, direct or indirect comparative studies using clinical data and validated outcomes measures are required to draw conclusions on the utility of ISDs compared to open surgery. A pivotal trial compared the Superion Interspinous Spacer with the X-STOP (which is no longer marketed), without conservative care or standard surgery comparators. The trial reported significantly better outcomes with the Superion Interspinous Spacer on some measures. For example, the trial reported more than 80% of patients experienced improvements in certain QOL outcome domains. Interpretation of this trial is limited by questions about the number of patients used to calculate success rates, the lack of efficacy of the comparator, and the lack of an appropriate control group treated by surgical decompression. The coflex interlaminar implant (formerly called the interspinous U) was compared with decompression in the multicenter, double-blind Foraminal Enlargement Lumbar Interspinous distraXion trial. Functional outcomes and pain levels were similar in the 2 groups at 1-year follow-up, but reoperation rates due to the absence of recovery were substantially higher with the coflex implant (29%) than with bony decompression (8%). For patients with 2-level surgery, the reoperation rate was 38% for coflex and 6% for bony decompression. At 2 years, reoperations due to the absence of recovery had been performed in 33% of the coflex group and 8% of the bony decompression group. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have severe spinal stenosis and grade 1 spondylolisthesis who have failed conservative therapy who receive an interlaminar spacer with spinal decompression surgery, the evidence includes two RCTs with a mixed population of patients. The relevant outcomes are symptoms, functional outcomes, QOL, and treatment-related morbidity. Use of the coflex interlaminar implant as a stabilizer after surgical decompression has been studied in two situations-as an adjunct to decompression compared with decompression alone (superiority) and as an alternative to spinal fusion after decompression (noninferiority). For decompression with coflex vs decompression with lumbar spinal fusion, the pivotal RCT, conducted in a patient population with spondylolisthesis no greater than grade 1 and significant back pain, showed that stabilization of decompression with the coflex implant was noninferior to decompression with spinal fusion for the composite clinical success (CCS) measure. A secondary (unplanned) analysis of patients with grade 1 spondylolisthesis (99 coflex patients and 51 fusion patients) showed a decrease in operative time (104 vs 157 minutes; p<0.001) and blood loss (106 vs 336 ml, p <0.001). There were no statistically significant differences between the coflex and fusion groups in Oswestry Disability Index (ODI), visual analog scale and Zurich Claudication Questionnaire scores after two years. In that analysis, 62.8% of coflex patients and 62.5% of fusion patients met the criteria for operative success. The efficacy of the comparator in this trial is uncertain because successful fusion was obtained in only 71% of the control group, leaving nearly a third of patients with pseudoarthrosis. The report indicated no significant differences in ODI or visual analog scale between the patients with pseudoarthrosis or solid fusion but Zurich Claudication Questionnaire scores were not reported. There were 18 (18%) spinous process fractures in the coflex group, of which 7 had healed by the 2-year follow-up. Reoperation rates were 6% in the fusion group and 14% in the coflex group (p=0.18), including 8 (8%) coflex cases that required conversion to fusion. This secondary analysis is considered hypothesis-generating, and a prospective trial in patients with grade 1 spondylolisthesis is needed. In an RCT conducted in a patient population with moderate-to-severe lumbar spinal stenosis with significant back pain and up to grade 1 spondylolisthesis, there was no difference in the primary outcome measure, the ODI, between the patients treated with coflex plus decompression vs. decompression alone. CCS-defined as a minimum 15-point improvement in ODI score, no reoperations, no device-related complications, no epidural steroid injections in the lumbar spine, and no persistent new or worsening sensory or motor deficit, was used to assess superiority. A greater proportion of patients who received coflex plus decompression instead of decompression alone achieved the composite endpoint. However, the superiority of coflex plus decompression is uncertain because the difference in the CCS was primarily driven by a greater proportion of patients in the control arm who received a secondary rescue epidural steroid injection. Because the trial was open-label, surgeons' decision to use epidural steroid injection could have been affected by their knowledge of the patient's treatment. Consequently, including this component in the CCS measure might have overestimated the potential benefit of treatment. Analysis was not reported separately for the group of patients who had grade 1 spondylolisthesis, leaving the question open about whether the implant would improve outcomes in this population. Consideration of existing studies as indirect evidence regarding the outcomes of using spacers in this subgroup is limited by substantial uncertainty regarding the balance of potential benefits and harms. The evidence is insufficient to determine that the technology results in an improvement in net health outcome.

For individuals who have spinal stenosis and no spondylolisthesis or instability who receive an interlaminar spacer with spinal decompression surgery, the evidence includes an RCT. The relevant outcomes are symptoms, functional outcomes, QOL, and treatment-related morbidity. The pivotal RCT, conducted in a patient population with spondylolisthesis no greater than grade 1 and significant back pain, showed that stabilization of decompression with the coflex implant was noninferior to decompression with spinal fusion for the CCS measure. However, in addition to concerns about the efficacy of fusion in this study, there is uncertainty about the net benefit of routinely adding spinal fusion to decompression in patients with no spondylolisthesis. Fusion after open decompression laminectomy is a more invasive procedure that requires longer operative time and has a potential for higher procedural and postsurgical complications. When the trial was conceived, decompression plus fusion was viewed as the standard of care for patients with spinal stenosis with up to grade 1 spondylolisthesis and back pain; thus demonstrating noninferiority with a less invasive procedure such as coflex would be adequate to result in a net benefit in health outcomes. However, the role of fusion in the population of patients represented in the pivotal trial is uncertain, especially since the publication of the Swedish Spinal Stenosis Study and the Spinal Laminectomy versus Instrumented Pedicle Screw, 2 RCTs comparing decompression alone with decompression plus spinal fusion that were published in 2016. As a consequence, results generated from a noninferiority trial using a comparator whose net benefit on health outcome is uncertain confounds meaningful interpretation of trial results. Therefore, demonstrating the noninferiority of coflex plus spinal decompression vs spinal decompression plus fusion, a comparator whose benefit on health outcomes is uncertain, makes it difficult to apply the results of the study. Outcomes from the subgoup of patients without spondylolisthesis who received an interlaminar device with decompression in the pivotal IDE trial have been published, but comparison with decompression alone in this population has not been reported. The evidence is insufficient to determine that the  technology  results in an improvement in the net health outcome.

Practice Guidelines and Position Statements

American Society of Pain and Neuroscience

In 2022, the American Society of Pain and Neuroscience published a consensus guideline outlining best practices for minimally invasive lumbar spinal stenosis treatment. The following recommendation was provided with regard to the use of interspinous spacers:

• "Interspinous spacers should be considered for treatment of symptomatic spinal stenosis at the index level with mild-to-moderate spinal stenosis, with less than or equal to grade 1 spondylolistheses, in the absence of dynamic instability or micro-instability represented as fluid in the facets on advanced imaging. Grade A; Level of certainty high; Quality of Evidence 1-A"

In 2022, ASPN also published evidence-based clinical guidelines informed by a systematic review of randomized controlled trials on interventional treatments for low back pain. The following recommendation was provided with regard to the use of interspinous spacers:

• "Stand-alone interspinous spacers for indirect decompression are safe and effective for the treatment of mild to moderate lumbar spinal stenosis if no contraindications exits. Grade A; Level of certainty high; Quality of Evidence: I-A."

Department of Health & Human Services

In 2019, a Department of Health & Human Services inter-agency task force released a report on pain management best practices. The report provides best practices for development of effective pain management plans using a patient-centered approach in the diagnosis and treatment of acute and chronic pain. All of their statements are on generalized pain and their recommendations relate to gaps in comprehensive pain plan development. In their report, regarding interspinous process spacer devices, they state: "research has shown that interspinous process spacer devices can provide relief for patients with lumbar spinal stenosis with neuroclaudication." The guidelines do not compare therapies to each other and is not informed by a systematic review, it only offers various options to consider when building a pain management plan for a patient.

International Society for the Advancement of Spine Surgery

In 2016, the International Society for the Advancement of Spine Surgery (ISASS) published recommendations/coverage criteria for decompression with interlaminar stabilization. ISASS concluded that an interlaminar spacer in combination with decompression can provide stabilization in patients who do not present with greater than grade 1 instability. Criteria included:

1. Radiographic confirmation of at least moderate lumbar stenosis.
2. Radiographic confirmation of the absence of gross angular or translatory instability of the spine at index or adjacent levels.
3. Patients who experience relief in flexion from their symptoms of leg/buttocks/groin pain, with or without back pain, and who have undergone at least 12 weeks of non-operative treatment.

The document did not address interspinous and interlaminar distraction devices without decompression.

North American Spine Society

The North American Spine Society (NASS; 2018) published specific coverage policy recommendations on the lumbar interspinous device without fusion and with decompression. NASS recommended that:

“Stabilization with an interspinous device without fusion in conjunction with laminectomy may be indicated as an alternative to lumbar fusion for degenerative lumbar stenosis with or without low-grade spondylolisthesis (less than or equal to 3 mm of anterolisthesis on a lateral radiograph) with qualifying criteria when appropriate:

1. Significant mechanical back pain is present (in addition to those symptoms associated with neural compression) that is felt unlikely to improve with decompression alone. Documentation should indicate that this type of back pain is present at rest and/or with movement while standing and does not have characteristics consistent with neurogenic claudication.
2. A lumbar fusion is indicated post-decompression for a diagnosis of lumbar stenosis with a Grade 1 degenerative spondylolisthesis as recommended in the NASS Coverage Recommendations for Lumbar Fusion.
3. A lumbar laminectomy is indicated as recommended in the NASS Coverage Recommendations for Lumbar Laminectomy.
4. Previous lumbar fusion has not been performed at an adjacent segment.
5. Previous decompression has been performed at the intended operative segment.

Interspinous devices are NOT indicated in cases that do not fall within the above parameters. In particular, they are not indicated in the following scenarios and conditions:

1. Degenerative spondylolisthesis of Grade 2 or higher.
2. Degenerative scoliosis or other signs of coronal instability.
3. Dynamic instability as detected on flexion-extension views demonstrating at least 3 mm of change in translation.
4. Iatrogenic instability or destabilization of the motion segment.
5. A fusion is otherwise not indicated for a Grade 1 degenerative spondylolisthesis and stenosis as per the NASS Coverage Recommendations for Lumbar Fusion.
6. A laminectomy for spinal stenosis is otherwise not indicated as per the NASS Coverage Recommendations for Lumbar Laminectomy.”

National Institute for Health and Care Excellence

The National Institute for Health and Clinical Excellence (NICE) published guidance in November 2010 stating that “Current evidence on interspinous distraction procedures for lumbar spinal stenosis causing neurogenic claudication shows that these procedures are efficacious for carefully selected patients in the short and medium term, although failure may occur and further surgery may be needed. The evidence reviewed consisted mainly of reports on X-STOP.

U.S. Preventive Services Task Force Recommendations

Not Applicable

KEY WORDS:

X-STOP, Interspinous Process Decompression device, IPD, lumbar spinal stenosis, lumbar stenosis, spinal stenosis, posterior spinal distraction device, Wallis® System, Diam™ Spine Stabilization System, Coflex™ Interspinous Implant, X-STOP PEEK, X-STOP® Interspinous Process Decompression (IPD®) System, Coflex® Interlaminar Technology implant, ExtendSure and CoRoent, NL-Pro,  Aperius, Falena, Interspinous distraction devices, Interspinous spacers, Superion ISS, VertiFlex, Interspinous U

APPROVED BY GOVERNING BODIES:

Three interspinous and interlaminar stabilization and distraction devices have been approved by the U.S. Food Drug Administration (FDA) through the premarket approval (FDA product code: NQO).

• X Stop Interspinous Process Decompression System (Medtronic).  This device was withdrawn from the market in 2015.
• Coflex® Interlaminar Technology (Paradigm Spine) in 2012.
• Superion® Indirect Decompression System (Vertiflex- acquired by Boston Scientific) in 2015.

In 2015 the Superion® Indirect Decompression System (formerly Interspinous Spacer) is indicated to treat skeletally mature patients suffering from pain, numbness, and/or cramping in the legs secondary to a diagnosis of moderate degenerative lumbar spinal stenosis, with or without grade 1 spondylolisthesis, confirmed by x-ray, magnetic resonance imaging, and/or computed tomography evidence of thickened ligamentum flavum, narrowed lateral recess, and/or central canal or foraminal narrowing. It is intended for those patients with impaired physical function who experience relief in flexion from symptoms of leg/buttock/groin pain, numbness, and/or cramping, with or without back pain, and who have undergone at least 6 months of nonoperative treatment.

FDA lists the following contraindications to use of the Superion® Indirect Decompression System:

• “An allergy to titanium or titanium alloy.
• Spinal anatomy or disease that would prevent implantation of the device or cause the device to be unstable in situ, such as:
  • Instability of the lumbar spine, e.g., isthmic spondylolisthesis or degenerative spondylolisthesis greater than grade 1 (on a scale of 1 to 4)
  • An ankylosed segment at the affected level(s)
  • Fracture of the spinous process, pars interarticularis, or laminae (unilateral or bilateral);
  • Scoliosis (Cobb angle >10 degrees)
• Cauda equina syndrome defined as neural compression causing neurogenic bladder or bowel dysfunction.
  • Diagnosis of severe osteoporosis, defined as bone mineral density (from DEXA [dual-energy x-ray absorptiometry] scan or equivalent method) in the spine or hip that is more than 2.5 S.D. below the mean of adult normal.
• Active systemic infection, or infection localized to the site of implantation.
• Prior fusion or decompression procedure at the index level.
• Morbid obesity defined as a body mass index (BMI) greater than 40.”

In 2012, the coflex® Interlaminar Technology implant (Paradigm Spine) is a single-piece U-shaped titanium alloy dynamic stabilization device with pairs of wings that surround the superior and inferior spinous processes. The coflex® (previously called the Interspinous U) is indicated for use in 1- or 2-level lumbar stenosis from the L1 to L5 vertebrae in skeletally mature patients with at least moderate impairment in function, who experience relief in flexion from their symptoms of leg/buttocks/groin pain, with or without back pain, and who have undergone at least 6 months of nonoperative treatment. The coflex® is intended to be implanted midline between adjacent lamina of 1 or 2 contiguous lumbar motion segments. Interlaminar stabilization is performed after decompression of stenosis at the affected level(s).

The FDA lists the following contraindications to use of the coflex®:

• Prior fusion or decompressive laminectomy at any index lumbar level.
• Radiographically compromised vertebral bodies at any lumbar level(s) caused by current or past trauma or tumor (e.g., compression fracture).
• Severe facet hypertrophy that requires extensive bone removal which would cause instability.
• Grade II or greater spondylolisthesis.
• Isthmic spondylolisthesis or spondylolysis (pars fracture).
• Degenerative lumbar scoliosis (Cobb angle of greater than 250 degrees).
• Osteoporosis.
• Back or leg pain of unknown etiology.
• Axial back pain only, with no leg, buttock, or groin pain.
• Morbid obesity defined as a body mass index >40.
• Active or chronic infection - systemic or local.
• Known allergy to titanium alloys or magnetic resonance imaging (MRI) contrast agents.
• Cauda equina syndrome defined as neural compression causing neurogenic bowel or bladder dysfunction.

The FDA labeling also contains multiple precautions and the following warning: “Data has demonstrated that spinous process fractures can occur with coflex® implantation.”

At the time of approval, the FDA requested additional postmarketing studies to provide longer-term device performance and device performance under general conditions of use. One study will provide 5-year follow-up of the cohort in the pivotal investigational device exemption (IDE) trial. The second will be a multi-center trial with 230 patients with follow-up at five years that compares decompression alone versus decompression plus coflex®. The third, a multicenter trial with 345 patients in the U.S. who were followed for 5 years, compared decompression alone with decompression plus coflex.

BENEFIT APPLICATION:

Coverage is subject to member’s specific benefits. Group-specific policy will supersede this policy when applicable.

ITS: Home Policy provisions apply

FEP:  Special benefit consideration may apply. Refer to the member’s benefit plan. 

CURRENT CODING:

CPT Codes:

HCPCS Codes:

REFERENCES:

1. Abdu WA, Lurie JD, Spratt KF, et al. Degenerative spondylolisthesis: does fusion method influence outcome? Four-year results of the spine patient outcomes research trial. Spine (Phila Pa 1976). Oct 1 2009;34(21):2351-2360.
2. Abjornson C, Yoon B-JV, Callanan T, Shein D, Grinberg S, Cammisa FP. Spinal stenosis in the absence of spondylolisthesis: can interlaminar stabilization at single and multi-levels provide sustainable relief? International journal of spine surgery. 2018;12(1):64-69.
3. Bae HW, Davis RJ, Lauryssen C, et al. Three-year follow-up of the prospective, randomized, controlled trial of Coflex interlaminar stabilization vs instrumented fusion in patients with lumbar stenosis. Neurosurgery. Aug 2016; 79(2):169-181.
4. Bae HW, Lauryssen C, Maislin G, et al. Therapeutic sustainability and durability of Coflex interlaminar stabilization after decompression for lumbar spinal stenosis: a four year assessment. Int J Spine Surg. 2015; 9:15.
5. Birkmeyer NJ, Weinstein JN, Tosteson AN, et al. Design of the Spine Patient Outcomes Research Trial (SPORT). Spine (Phila Pa 1976). 2002;27(12):1361-1372.
6. Chou R, Deyo R, Friedly J, et al. Nonpharmacologic therapies for low back pain: a systematic review for an American College of Physicians Clinical Practice Guideline. Ann Intern Med. 2017;166(7):493-505.
7. Crawford CH, 3rd, Glassman SD, Mummaneni PV, Knightly JJ, Asher AL. Back pain improvement after decompression without fusion or stabilization in patients with lumbar spinal stenosis and clinically significant preoperative back pain. Journal of neurosurgery Spine. 2016;25(5):596-601.
8. Dartmouth Institute. Variation in the care of surgical conditions: spinal stenosis. 2014.
9. Davis RJ, Errico TJ, Bae H et al. Decompression and Coflex interlaminar stabilization compared with decompression and instrumented spinal fusion for spinal stenosis and low-grade degenerative spondylolisthesis: two-year results from the prospective, randomized, multicenter, Food and Drug Administration Investigational Device Exemption trial. Spine (Phila Pa 1976) 2013; 38(18):1529-1539.
10. Davis R, Auerbach JD, Bae H et al. Can low-grade spondylolisthesis be effectively treated by either Coflex interlaminar stabilization or laminectomy and posterior spinal fusion? Two-year clinical and radiographic results from the randomized, prospective, multicenter US investigational device exemption trial: clinical article. J Neurosurg Spine 2013; 19(2):174-184.
11. Deer TR, Grider JS, Pope JE, et al. Best Practices for Minimally Invasive Lumbar Spinal Stenosis Treatment 2.0 (MIST): Consensus Guidance from the American Society of Pain and Neuroscience (ASPN). J Pain Res. 2022; 15: 1325-1354.
12. Delitto A, Piva SR, Moore CG, et al. Surgery versus nonsurgical treatment of lumbar spinal stenosis: a randomized trial. Ann Intern Med. 2015;162(7):465-473.
13. Deyo RA, Mirza SK, Martin BI, et al. Trends, major medical complications, and charges associated with surgery for lumbar spinal stenosis in older adults. Jama. Apr 7 2010;303(13):1259-1265.
14. Dijkerman ML, Overdevest GM, Moojen WA, et al. Decompression with or without concomitant fusion in lumbar stenosis due to degenerative spondylolisthesis: a systematic review. Eur Spine J. Jul 2018;27(7):1629-1643.
15. El Tecle NE, Dahdaleh NS. Fusion surgery for lumbar spinal stenosis [letter]. N Engl J Med. Aug 11 2016;375(6):597.
16. Food and Drug Administration. Summary of Safety and Effectiveness Data (SSED): coflex Interlaminar Technology. 2012; https://www.accessdata.fda.gov/cdrh_docs/pdf11/P110008b.pdf. Accessed May 18, 2018.
17. Forsth P, Michaelsson K, Sanden B. Fusion surgery for lumbar spinal stenosis [letter]. N Engl J Med. Aug 11 2016;375(6):599-600.
18. Forsth P, Olafsson G, Carlsson T, et al. A randomized, controlled trial of fusion surgery for lumbar spinal stenosis. N Engl J Med. Apr 14 2016;374(15):1413-1423.
19. Fritz JM, Lurie JD, Zhao W, et al. Associations between physical therapy and long-term outcomes for individuals with lumbar spinal stenosis in the SPORT study. The spine journal : official journal of the North American Spine Society. 2014;14(8):1611-1621.
20. Genevay S, Atlas SJ, Katz JN. Variation in eligibility criteria from studies of radiculopathy due to a herniated disc and of neurogenic claudication due to lumbar spinal stenosis: a structured literature review. Spine (Phila Pa 1976). Apr 1 2010;35(7):803-811.
21. Ghogawala Z, Dziura J, Butler WE, et al. Laminectomy plus fusion versus laminectomy alone for lumbar spondylolisthesis. N Engl J Med. Apr 14 2016;374(15):1424-1434.
22. Gilbert OE, Lawhon SE, Gaston TL, et al. Decompression and Interlaminar Stabilization for Lumbar Spinal Stenosis: A Cohort Study and Two-Dimensional Operative Video. Medicina (Kaunas). Apr 05 2022; 58(4).
23. Grinberg SZ, Simon RB, Dowe C, et al. Interlaminar stabilization for spinal stenosis in the Medicare population. Spine J. Dec 2020; 20(12): 1948-1959.
24. Guyer RD, Musacchio MJ, Cammisa FP, et al. ISASS recommendations/coverage criteria for decompression with interlaminar stabilization - coverage indications, limitations, and/or medical necessity. Int J Spine Surg. 2016; 10: Article 41.
25. Hagedorn JM, Yadav A, D'Souza RS, et al. The incidence of lumbar spine surgery following Minimally Invasive Lumbar Decompression and Superion Indirect Decompression System for treatment of lumbar spinal stenosis: a retrospective review. Pain Pract. Jun 2022; 22(5): 516-521.
26. Haig AJ, Tomkins CC. Diagnosis and management of lumbar spinal stenosis. Jama. 2010;303(1):71-72.
27. IOM (Institute of Medicine). 2011. Clinical Practice Guidelines We Can Trust. Washington, DC: The National Academies Press.
28. Inose H, Kato T, Yuasa M, et al. Comparison of decompression, decompression plus fusion, and decompression plus stabilization for degenerative spondylolisthesis: a prospective, randomized study. Clin Spine Surg. 2018;31(7):E347-E352.
29. Katz JN. Surgery for lumbar spinal stenosis: informed patient preferences should weigh heavily. Ann Intern Med. 2015;162(7):518-519.
30. Lachin JM. Fallacies of last observation carried forward analyses. Clinical trials. 2016;13(2):161-168.
31. Lee N, Shin DA, Kim KN, et al. Paradoxical radiographic changes of Coflex Interspinous device with minimum 2-year follow-up in lumbar spinal stenosis. World Neurosurg. Jan 2016; 85:177-184.
32. Lurie J, Tomkins-Lane C. Management of lumbar spinal stenosis. BMJ. 2016;352:h6234.
33. Lurie JD, Tosteson TD, Tosteson A, et al. Long-term outcomes of lumbar spinal stenosis: eight-year results of the Spine Patient Outcomes Research Trial (SPORT). Spine (Phila Pa 1976). 2015;40(2):63-76.
34. Moojen WA, Arts MP, Jacobs WC et al. Interspinous process device versus standard conventional surgical decompression for lumbar spinal stenosis: randomized controlled trial. BMJ 2013; 347:f6415.
35. Moojen WA, Arts MP, Jacobs WC, et al. IPD without bony decompression versus conventional surgical decompression for lumbar spinal stenosis: 2-year results of a double-blind randomized controlled trial. Eur Spine J. Oct 2015; 24(10):2295-2305.
36. Moojen W, Arts M, Jacobs W, et al. The Felix Trial: clinical results after one year and subgroup analysis: Introducing new implants and imaging techniques for lumbar spinal stenosis [doctoral dissertation], Universiteit Leiden; 2014;69-90.
37. Musacchio MJ, Lauryssen C, Davis RJ, et al. Evaluation of decompression and interlaminar stabilization compared with decompression and fusion for the treatment of lumbar spinal stenosis: five-year follow-up of a prospective, randomized, controlled trial. Int J Spine Surg. 2016; 10:6.
38. National Institute for Health and Clinical Excellence. Interspinous distraction procedures for lumbar spinal stenosis causing neurogenic claudication. November 2010. www.guidance.nice.org.uk/IPG365.
39. North American Spine Society. NASS Coverage Policy Recommendations: Lumbar interspinous device without fusion & with decompression. Burr Ridge, IL: NASS; 2018.
40. Nunley, PP, Deer, TT, Benyamin, RR, Staats, PP, Block, JJ. Interspinous process decompression is associated with a reduction in opioid analgesia in patients with lumbar spinal stenosis. J Pain Res, 2018 Dec 13;11:2943-2948.
41. Nunley PD, Patel VV, Orndorff DG, et al. Interspinous Process Decompression Improves Quality of Life in Patientswith Lumbar Spinal Stenosis. Minim Invasive Surg. 2018; 2018: 1035954.
42. Nunley PD, Patel VV, Orndorff DG, Lavelle WF, Block JE, Geisler FH. Superion interspinous spacer treatment of moderate spinal stenosis: 4-year results. World neurosurgery. 2017;104:279-283.
43. Nunley PD, Patel VV, Orndorff DG, Lavelle WF, Block JE, Geisler FH. Five-year durability of stand-alone interspinous process decompression for lumbar spinal stenosis. Clinical interventions in aging. 2017;12:1409-1417.
44. Patel VV, Nunley PD, Whang PG, et al. Superion((R)) interspinous spacer for treatment of moderate degenerative lumbar spinal stenosis: durable three-year results of a randomized controlled trial. J Pain Res. 2015; 8:657-662.
45. Patel VV, Whang PG, Haley TR, et al. Superion interspinous process spacer for intermittent neurogenic Claudication Secondary to Moderate Lumbar Spinal Stenosis: Two-Year Results From a Randomized Controlled FDA-IDE Pivotal Trial. Spine (Phila Pa 1976). Dec 9 2015; 40(5):275-282.
46. Pearson A, Blood E, Lurie J, et al. Degenerative spondylolisthesis versus spinal stenosis: does a slip matter? Comparison of baseline characteristics and outcomes (SPORT). Spine (Phila Pa 1976). Feb 1 2010;35(3):298-305.
47. Pearson A, Blood E, Lurie J, et al. Predominant leg pain is associated with better surgical outcomes in degenerative spondylolisthesis and spinal stenosis: results from the Spine Patient Outcomes Research Trial (SPORT). Spine (Phila Pa 1976). Feb 1 2011;36(3):219-229.
48. Pearson AM. Fusion in degenerative spondylolisthesis: how to reconcile conflicting evidence. J Spine Surg. Jun 2016; 2(2): 143-5.
49. Peul WC, Moojen WA. Fusion surgery for lumbar spinal stenosis [letter]. N Engl J Med. Aug 11 2016;375(6):601.
50. Richter A, Schutz C, Hauck M et al. Does an interspinous device (Coflex) improve the outcome of decompressive surgery in lumbar spinal stenosis? One-year follow up of a prospective case control study of 60 patients. Eur Spine J 2010; 19(2):283-289.
51. Richter A, Halm HF, Hauck M et al. Two-year follow-up after decompressive surgery with and without implantation of an interspinous device for lumbar spinal stenosis: a prospective controlled study. J Spinal Disord Tech. Aug 2014; 27(6):336-341.
52. Roder C, Baumgartner B, Berlemann U, et al. Superior outcomes of decompression with an interlaminar dynamic device versus decompression alone in patients with lumbar spinal stenosis and back pain: a cross registry study. Eur Spine J. Oct 2015; 24(10):2228-2235.
53. Rosner HL, Tran O, Vajdi T, et al. Comparison analysis of safety outcomes and the rate of subsequent spinal procedures between interspinous spacer without decompression versus minimally invasive lumbar decompression. Reg Anesth Pain Med. Jan 11 2024; 49(1): 30-35.
54. Sayed D, Grider J, Strand N, et al. The American Society of Pain and Neuroscience (ASPN) Evidence-Based Clinical Guideline of Interventional Treatments for Low Back Pain. J Pain Res. 2022; 15: 3729-3832.
55. Schmidt S, Franke J, Rauschmann M, Adelt D, Bonsanto MM, Sola S. Prospective, randomized, multicenter study with 2-year follow-up to compare the performance of decompression with and without interlaminar stabilization. Journal of neurosurgery Spine. 2018:1-10.
56. Schroeder GD, Kurd MF, Vaccaro AR. Lumbar spinal stenosis: How is it classified? The Journal of the American Academy of Orthopaedic Surgeons. 2016;24(12):843-852.
57. Simon RB, Dowe C, Grinberg S, Cammisa FP, Abjornson C. The 2-Level Experience of Interlaminar Stabilization: 5-Year Follow-Up of a Prospective, Randomized Clinical Experience Compared to Fusion for the Sustainable Management of Spinal Stenosis. International journal of spine surgery. 2018;12(4):419.
58. Su BW, Vaccaro AR. Fusion surgery for lumbar spinal stenosis [letter]. N Engl J Med. Aug 11 2016;375(6):597-598.
59. Tekmyster G, Sayed D, Cairns KD, et al. Interspinous Process Decompression With The Superion (R) Spacer For Lumbar Spinal Stenosis: Real-World Experience From A Device Registry. Med Devices (Auckl). 2019; 12: 423-427.
60. Tian NF, Wu AM, Wu LJ, et al. Incidence of heterotopic ossification after implantation of interspinous process devices. Neurosurg Focus. Aug 2013; 35(2):E3.
61. US Department of Health and Human Services. Pain management best practices; 2019. www.hhs.gov/sites/default/files/pmtf-final-report-2019-05-23.pdf.
62. Vasudeva VS, Chi JH. Fusion surgery for lumbar spinal stenosis [letter]. N Engl J Med. Aug 11 2016;375(6):598.
63. Whang PG, Tran O, Rosner HL. Longitudinal Comparative Analysis of Complications and Subsequent Interventions Following StandAlone Interspinous Spacers, Open Decompression, or Fusion for Lumbar Stenosis. Adv Ther. Aug 2023; 40(8): 3512-3524.
64. Xin JH, Che JJ, Wang Z, et al. Effectiveness and safety of interspinous spacer versus decompressive surgery for lumbar spinal stenosis: A meta-analysis of randomized controlled trials. Medicine (Baltimore). Nov 17 2023; 102(46): e36048.
65. Yoshihara H, Yoneoka D. National trends in the surgical treatment for lumbar degenerative disc disease: United States, 2000 to 2009. Spine J. Feb 1 2015;15(2):265-271.
66. Zheng X, Chen Z, Yu H, et al. A minimum 8-year follow-up comparative study of decompression and coflex stabilization with decompression and fusion. Exp Ther Med. Jun 2021; 21(6): 595. 
67. Zhong J, O'Connell B, Balouch E, et al. Patient Outcomes After Single Level Coflex (R) Interspinous Implants versus Single Level Laminectomy. Spine (Phila Pa 1976). Dec 31 2020; Publish Ahead of Print.

POLICY HISTORY:

Medical Policy Group, June 2006 (1)
Medical Policy Administration Committee, June 2006
Available for comment July 5-August 18, 2006
Medical Policy Group, June 2008 (1)
Medical Policy Panel May 2009
Medical Policy Group, June 2009 (2)
Medical Policy Administration Committee, July 2009
Medical Policy Group, August 2011
Medical Policy Group (2): 2012 Updates-Description, Key Points, Key Words, Approved by Governing Bodies, References
Medical Policy Panel, December 2012
Medical Policy Group, March 20013 (2): Policy updated with literature review through September 2012; policy statement unchanged, FDA approval information added on Corflex® Interlaminar Technology implant, Key Words, Key Points and References updated.
Medical Policy Panel, May 2013
Medical Policy Group, August 2013 (2): Policy updated with literature review through April 2013.  Investigational policy statement added on interlaminar stabilization devices; interlaminar stabilization added to title.  Policy statement added that interlaminar stabilization device following decompressive surgery is investigational. Description, Key Points, and References updated to reflect changes. 
Available for comment August 22 through October 5, 2013
Medical Policy Panel, May 2014
Medical Policy Group, May 2014 (4): Updated Key Points and References, No changes in policy statement at this time.
Medical Policy Panel, April 2015
Medical Policy Group, April 2015 (2): Updated Key Points, Approved by Governing Bodies, and References; no change to policy statement.
Medical Policy Panel, April 2016
Medical Policy Group, April 2016 (7): Updated Key Points, Key Words, Approved by Governing Bodies, and References; no change to policy statement.
Medical Policy Group, December 2016: 2017 Annual Coding Update. Created Previous Coding section and moved deleted codes 0271T and 0272T to this section; added codes 22867 – 22870 to Current Coding.
Medical Policy Panel, April 2017
Medical Policy Group, April 2017 (7): Updates to Key Points and References; clarification to Policy Statement, no change in intent.
Medical Policy Panel, December 2018
Medical Policy Group, January 2019 (7): Updates to Description, Key Points and References. No change to Policy Statement.
Medical Policy Panel, April 2019
Medical Policy Group, May 2019 (7): Updates to Key Points and References. No change to Policy Statement. Removed Previous Coding section.
Medical Policy Panel, September 2019
Medical Policy Group, October 2019 (7): Updates to Key Points. No change to Policy Statement.
Medical Policy Panel, April 2020
Medical Policy Group, May 2020 (7): Updates to Key Points and References. No change to Policy Statement.
Medical Policy Panel, April 2021

Medical Policy Group, April 2021 (7): Updates to Key Points, Approved Governing Bodies, and References. Policy statement updated to remove “not medically necessary,” no change to policy intent.

Medical Policy Panel, April 2022

Medical Policy Group, May 2022 (7): Updates to Key Points and References. No change to Policy Statement.

Medical Policy Panel, April 2023

Medical Policy Group, May 2023 (7): Updates to Key Points, Benefit Application, and References. No change to Policy Statement.

Medical Policy Panel, April 2024

Medical Policy Group, May 2024 (7): Updates to Description, Key Points, Approved by Governing Bodies, and References. No change to Policy Statement.

This medical policy is not an authorization, certification, explanation of benefits, or a contract. Eligibility and benefits are determined on a case-by-case basis according to the terms of the member’s plan in effect as of the date services are rendered. All medical policies are based on (i) research of current medical literature and (ii) review of common medical practices in the treatment and diagnosis of disease as of the date hereof. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment.

This policy is intended to be used for adjudication of claims (including pre-admission certification, pre-determinations, and pre-procedure review) in Blue Cross and Blue Shield’s administration of plan contracts.

The plan does not approve or deny procedures, services, testing, or equipment for our members. Our decisions concern coverage only. The decision of whether or not to have a certain test, treatment or procedure is one made between the physician and his/her patient. The plan administers benefits based on the member’s contract and corporate medical policies. Physicians should always exercise their best medical judgment in providing the care they feel is most appropriate for their patients. Needed care should not be delayed or refused because of a coverage determination.

As a general rule, benefits are payable under health plans only in cases of medical necessity and only if services or supplies are not investigational, provided the customer group contracts have such coverage.

The following Association Technology Evaluation Criteria must be met for a service/supply to be considered for coverage:

1. The technology must have final approval from the appropriate government regulatory bodies;
2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes;
3. The technology must improve the net health outcome;
4. The technology must be as beneficial as any established alternatives;
5. The improvement must be attainable outside the investigational setting.

Medical Necessity means that health care services (e.g., procedures, treatments, supplies, devices, equipment, facilities or drugs) that a physician, exercising prudent clinical judgment, would provide to a patient for the purpose of preventing, evaluating, diagnosing or treating an illness, injury or disease or its symptoms, and that are:

1. In accordance with generally accepted standards of medical practice; and
2. Clinically appropriate in terms of type, frequency, extent, site and duration and considered effective for the patient’s illness, injury or disease; and
3. Not primarily for the convenience of the patient, physician or other health care provider; and
4. Not more costly than an alternative service or sequence of services at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of that patient’s illness, injury or disease.