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Interspinous Fixation (Fusion) Devices

Policy Number: MP-514

Latest Review Date: May 2022

Category:  Surgery                                                                 



Interspinous fixation (fusion) devices are considered investigational for any indication, including but not limited to use:

  • In combination with interbody fusion, OR
  • Alone for decompression in patients with spinal stenosis. 


Interspinous fixation (fusion) devices are being developed to aid in the stabilization of the spine.  They are being evaluated as alternatives to pedicle screw and rod constructs in combination with interbody fusion. Interspinous fixation devices (IFDs) are also being evaluated for stand-alone use in patients with spinal stenosis and/or spondylolisthesis.

Contemporary models of interspinous fixation devices have evolved from spinous process wiring with bone blocks and early device designs (e.g., Wilson plate, Meurig-Williams system, Daab plate). The newer devices range from paired plates with teeth to U-shaped devices with wings that are attached to the spinous process. They are intended to be an alternative to pedicle screw and rod constructs to aid in the stabilization of the spine with interbody fusion. Interspinous fixation devices are placed under direct visualization, while screw and rod systems may be placed either under direct visualization or percutaneously.  Use of an interspinous fixation device in combination with a unilateral pedicle screw system has also been proposed.  Interspinous fixation devices are not intended for stand-alone use.

Unlike IFDs, interspinous distraction devices (spacers) are used alone for decompression and are typically not fixed to the spinous process. In addition, interspinous distraction devices have been designed for dynamic stabilization, whereas, interspinous fixation devices are rigid. However, IFDs might also be used to distract the spinous processes and decrease lordosis. Thus, IFDs could be used off-label without interbody fusion as decompression (distraction) devices in patients with spinal stenosis.  If IFDs are used alone as a spacer, there is a risk of spinous process fracture.

For use in combination with fusion, it has been proposed that interspinous fixation systems are less invasive and present fewer risks than pedicle or facet screws. While biomechanical studies have indicated that interspinous fixation devices may be similar to pedicle screw-rod constructs in limiting the range of flexion-extension, they may be less effective than bilateral pedicle screw-rod fixation for limiting axial rotation and lateral bending. There is a potential for a negative impact on the interbody cage and bone graft due to focal kyphosis resulting from the IFD. There is also a potential for spinous process fracture.

See “Interspinous and Interlaminar Stabilization/Distraction Devices (Spacers)” (Policy #282) for discussion and coverage of interspinous distraction devices.


This policy was created and updated periodically using the MEDLINE database. The most recent update was performed through January 17, 2022.

Summary of Evidence

For individuals who are undergoing spinal fusion who receive an interspinous fixation device (IFD) with interbody fusion, the evidence includes a systematic review of nonrandomized comparative studies and case series, and 2 small RCTs. Relevant outcomes are symptoms, functional outcomes, quality of life, resource utilization, and treatment-related morbidity. There is a lack of evidence on the efficacy of IFDs in combination with interbody fusion. One risk is spinous process fracture, while a potential benefit is a reduction in adjacent segment degeneration. Randomized trials with longer follow-up are needed to evaluate risks and benefits following use of interspinous fixation (fusion) devices in comparison with the established standard of pedicle screw-rod fixation. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have spinal stenosis and/or spondylolisthesis who receive an IFD alone, the evidence includes a retrospective series. Relevant outcomes are symptoms, functional outcomes, quality of life, resource utilization, and treatment-related morbidity. There is a lack of evidence on the efficacy of interspinous fixation devices as a stand-alone procedure. RCTs are needed that evaluate health outcomes following use of interspinous fixation (fusion) devices when used alone for decompression. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.


In 2019, the North American Spine Society issued a coverage position on the use of interspinous devices with lumbar fusion. The Society noted that although there is still limited evidence, interspinous fixation with fusion for stabilization may be considered when utilized in the context of lumbar fusion procedures for patients with diagnoses including stenosis, disc herniations, or synovial facet cysts in the lumbar spine, as an adjunct to cyst excision which involves removal of greater than 50 percent of the facet joint and when utilized in conjunction with a robust open laminar and/or facet decortication and fusion, and/or a robust autograft inter- and extraspinous process decortication and fusion, and/or an interbody fusion of the same motion segment. The Society also noted that "No literature supports the use of interspinous fixation without performing an open decortication and fusion of the posterior bony elements or interbody fusion."


Not applicable.


Interspinous fixation devices, interspinous fusion devices, Affix™, Aileron™, Aspen™, Axle™, BacFuse®, BridgePoint, coflex-F®, PrimaLok™, Spire™, SP-Fix™, spondylolisthesis, ZIP® MIS, InterBridge®, Inspan™, Minuteman™, Octave™


The following interspinous fixation devices have been cleared for marketing by the U.S. Food and Drug Administration (FDA) through the 510(k) process. This list may not be exhaustive.

  • Aerial™ Interspinous Fixation (Globus Medical Inc.)
  • Affix™ (NuVasive)
  • Aileron™ (Life Spine)
  • Aspen™ (Lanx, acquired by BioMet)
  • Axle™ (X-Spine)
  • BacFuse® (Pioneer Surgical)
  • BridgePoint™ (Alphatec)
  • coflex-F® (Paradigm Spine)
  • Inspan™ (Spine Frontier)
  • InterBRIDGE Interspinous Posterior Fixation System (LDR Spine)
  • Minuteman™ (Spinal Simplicity)
  • Octave™ (Life Span)
  • PrimaLok™ (OsteoMed)
  • Spire™ (Medtronic)
  • SP-Fix™ (Globus)
  • SP-Link™ System (Medical Designs LLC)
  • ZIP® MIS Interspinous Fusion System (Aurora Spine).

Interspinous fixation devices are intended to be used as an adjunct to interbody fusion.  For example, the indication for use of the coflex-F implant:

“is a posterior, non-pedicle supplemental fixation device intended for use with an interbody cage as an adjunct to fusion at a single level in the lumbar spine (L1-S1).  It is intended for attachment to the spinous processes for the purpose of achieving stabilization to promote fusion in patients with degenerative disc disease—defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies—with up to Grade 1 spondylolisthesis.” 

A number of interspinous plate systems have also been cleared for marketing by FDA.

Use of an interspinous fixation device for a stand-alone procedure would be considered off-label. 


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 member’s benefit plan.  FEP does not consider investigational if FDA approved and will be reviewed for medical necessity.


There are no specific CPT codes for insertion of these devices.  The following might be used:

CPT Codes:


Unlisted procedure, spine


  1. Huang WM, Yu XM, Xu XD, et al. Posterior Lumbar Interbody Fusion with Interspinous Fastener Provides Comparable Clinical Outcome and Fusion Rate to Pedicle Screws. Orthop Surg. 2017 May;9(2).
  2. Lopez AJ, Scheer JK, Dahdaleh NS, et al. Lumbar spinous process fixation and fusion: a systematic review and critical analysis of an emerging spinal technology. Clin Spine Surg. Nov 2017;30(9):E1279-E1288.
  3. North American Spine Society (NASS). NASS coverage policy recommendations: Interspinous fixation with fusion. Revised December 2019.
  4. Panchal R, Denhaese R, Hill C, et al. Anterior and Lateral Lumbar Interbody Fusion With Supplemental Interspinous Process Fixation: Outcomes from a Multicenter, Prospective, Randomized, Controlled Study. Int J Spine Surg. 2018 Apr;12(2).
  5. Sclafani JA, Liang K, Ohnmeiss DD, et al. Clinical outcomes of a polyaxial interspinous fusion system. Int J Spine Surg. 2014; 8.
  6. Wu JC, Mummaneni PV. Using lumbar interspinous anchor with transforaminal lumbar interbody fixation. World Neurosurg 2010; 73(5):471-472.


Medical Policy Panel, September 2012

Medical Policy Group, September 2012 (2): New policy. Non-covered/investigational statement

Medical Policy Administration Committee, October 2012

Available for comment October 24 through December 10, 2012

Medical Policy Panel, September 2013

Medical Policy Group, September 2013 (4): Key Points updated. No change in policy statement at this time. 

Medical Policy Panel, September 2014

Medical Policy Group, September 2014 (3):  2014 Updates to Key Points, Governing Bodies & References; no change in policy statement.

Medical Policy Panel, September 2015

Medical Policy Group, October 2015 (2): 2015 Updates to Description, Key Points, Approved by Governing Bodies, and References, no change in policy statement.

Medical Policy Group, December 2016: Annual Coding Update. Added CPT codes 22853, 22854, and 22859.  Created Previous Coding section and moved deleted code 22851 to this new section.

Medical Policy Panel, April 2017

Medical Policy Group, April 2017 (7): 2017 Updates to Description, Key Points, Key Words, Approved by Governing Bodies & References; no change in policy statement.

Medical Policy Group, June 2017 (7): Removed CPT codes 22840, 22853, 22854, 22859 from Coding section as there are no specific codes for these devices; added CPT 22899.

Medical Policy Panel, May 2018

Medical Policy Group, May 2018 (7): 2018 Updates to Key Points and References. No change in Policy Statement.

Medical Policy Panel, April 2019

Medical Policy Group, April 2019 (7): 2018 Updates to Key Points and References. No change in Policy Statement.

Medical Policy Panel, April 2020

Medical Policy Group, May 2020 (7): Updates to Key Points, Approved by Governing Bodies and References. Removed Previous Coding Section: CPT 22851 deleted effective 12/31/16.  No change in Policy Statement.

Medical Policy Panel, April 2021

Medical Policy Group, April 2021 (7): Updates to Description, Key Points, 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): Minor update to Key Points. No new literature to add. 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.