Interspinous Distraction Devices

» Summary» Procedure Codes
» Description» Selected References
» Prior Approval» Policy History
» Policy

Medical Policy: 07.01.35 
Original Effective Date: January 2007 
Reviewed: March 2015 
Revised: May 2013 

Benefit Application
Benefit determinations are based on the applicable contract language in effect at the time the services were rendered. Exclusions, limitations or exceptions may apply. Benefits may vary based on contract, and individual member benefits must be verified. Wellmark determines medical necessity only if the benefit exists and no contract exclusions are applicable. This medical policy may not apply to FEP. Benefits are determined by the Federal Employee Program.

This Medical Policy document describes the status of medical technology at the time the document was developed. Since that time, new technology may have emerged or new medical literature may have been published. This Medical Policy will be reviewed regularly and be updated as scientific and medical literature becomes available.


Interspinous implants are intended to restrict painful motion while otherwise enabling normal motion. The devices, also known as spacers, distract the spinous processes and restrict extension. Theoretically, this enlarges the neural foramen in patients with spinal stenosis and neurogenic claudication. The spacer is inserted between the spinous processes through a small incision. The supraspinous ligament is maintained and assists in holding the implant in place.


In November 2005, the X-STOP® Interspinous Process Decompression System was approved by the Food and Drug Administration (FDA) for treatment of patients aged 50 or older suffering from neurogenic intermittent claudication secondary to a confirmed diagnosis of lumbar spinal stenosis. It is approved for those who have had a regimen of at least six months of non-operative treatment and who have relief of their pain when in flexion. The device is approved for implantation at one or two lumbar levels in patients whose condition warrants surgery at no more than two levels. The X-STOP® PEEK IPD® System, a modified version of the original X-STOP system, received FDA approval in 2006.


The coflex® Interlaminar Technology implant (Paradigm Spine) was approved by the FDA in 2012 (P110008). It 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® is indicated for use in 1- or 2-level lumbar stenosis from L1-L5 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 non-operative 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 North American Spine Society (2011 revised clinical guideline) concluded that “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” (Grade of Recommendation I - Insufficient Evidence).


Current evidence is insufficient to permit conclusions about whether any beneficial effect from interspinous process distraction or interlaminar stabilization spacers provides a significant advantage over surgical decompression, which is the current standard of care for surgical treatment of lumbar spinal stenosis. In addition, the complication rates and reoperation rates for these spacers compared with those of decompression surgery is unknown.


Prior Approval: 


Not applicable



Interspinous distraction devices are considered investigational.


There is insufficient evidence in the peer-reviewed medical literature to demonstrate the long-term safety and efficacy of interspinous distraction devices and the durability of the devices.  The impact of this technology on net health outcome is not known. There is a need for longer-term outcome data on symptom relief, the need for repeat procedures, and implant survival.


Procedure Codes and Billing Guidelines: 

  • To report provider services, use appropriate CPT* codes, Modifiers, Alpha Numeric (HCPCS level 2) codes, Revenue codes, and/or diagnosis codes.
  • 0171T Insertion of posterior spinous process distraction device (including necessary removal of bone or ligament for insertion and imaging guidance), lumbar; single level
  • 0172T Insertion of posterior spinous process distraction device (including necessary removal of bone or ligament for insertion and imaging guidance), lumbar; each additional level (List separately in addition to code for primary procedure)
  • C1821 Interspinous process distraction device (implantable)


Selected References: 

  • Zucherman JR, Hsu KY, Hartjen CA et al. A multicenter, prospective, randomized trial evaluating the X STOP interspinous process decompression system for the treatment of neurogenic intermittent claudication: two-year follow-up results. Spine. 2005;30(12):1351-8.
  • Talwar V, Lindsey DP, Fredrick A et al. Insertion loads of the X STOP interspinous process distraction system designed to treat neurogenic intermittent claudication. Eur Spine J. 2005 May 31.
  • Sengupta DK. Dynamic stabilization devices in the treatment of lower back pain. Orthop Clin North Am. 2004 Jan; 35(1):43-56.
  • Lee J, Hida K, Seki T et al. An interspinous process distractor (X STOP) for lumbar spinal stenosis in elderly patients: preliminary experiences in 10 consecutive cases. J Spinal Disord Tech. 2004 Feb; 17(1):72-7.
  • Richards JC, Majumdar S, Lindsey DP et al. The treatment mechanism os an interspinous process implant for lumbar neurogenic intermittent claudication. Spine. 2005;30(7): 744-49.
  • Kondrashov DG, Hannibal M, Hsu KY et al. Interspinous process decompression with the X-STOP device for lumbar spinal stenosis: a 4-year follow-up study. J Spinal Disord Tech. 2006 Jul;19(5):323-7.
  • AndersonPA, Tribus CB, Kitchel SH. Treatment of neurogenic claudication by interspinous decompression: application of the X STOP device in patients with lumbar degenerative spondylolisthesis. J Neurosurg Spine. 2006 Jun;4(6):463-71.
  • National Institute for Clinical Excellence (NICE). Interventional procedure overview of interspinous distraction procedures for spinal stenosis causing neurogenic claudication in the lumbar spine. London, UK: NICE; 2005 Nov.
  • North American Spine Society. Evidence-based clinical guidelines for multidisciplinary spine care: Diagnosis and treatment of degenerative lumbar spinal stenosis. January 2007 Available at: http//
  • Verhoof OJ, Bron JL, Wapstra FH, van Royen BJ. High failure rate of the interspinous distraction device (X-STOP) for the treatment of lumbar spinal stenosis caused by degenerative spondylolisthesis. Eur Spine J, 2008 Feb;17(2):188-92.
  • ECRI. Interspinous Process Decompression to Treat Spinal Stenosis. Plymouth Meeting (PA): ECRI Health Technology Information Service; 2007 August 14. (ECRI Hotline Response)
  • ECRI Institute. Interspinous process decompression to treat spinal stenosis. Plymouth Meeting (PA): ECRI Health Technology Information Service; 2009 Oct. 7. 11 p. [ECRI hotline response].
  • ECRI Institute.  Interspinous process decompression to treat spinal stenosis. Plymouth Meeting (PA):ECRI Health Technology Information Service; 2011 Mar 17 p. 11 [ECRI hotline response].
  • North American Spine Society (NASS). Diagnosis and treatment of degenerative lumbar spinal stenosis. Burr Ridge, IL: North American Spine Society (NASS); December 2011.
  • Kim DH, Tantorski M, Shaw J, et al. Occult spinous process fractures associated with interspinous process spacers. Spine (Phila Pa 1976). 2011;36(16):E1080-E1085.
  • Davis R, Auerbach D, et al. Can low grade spondylolisthesis be effectively treated by either coflex interlaminar stabilization or laminectomy and posterior spinal fusion? J Neurosurg: Spine May 31, 2013.]
  • North American Spine Society. Interspinous device without fusion. 2014. Available online at: nWithFusion.pdf .


Policy History: 



Date                                        Reason                               Action

June 2011                               Annual review                    Policy renewed

May 2012                               Annual review                     Policy renewed

May 2013                               Annual review                     Policy renewed

April 2014                               Annual review                     Policy renewed

March 2015                            Annual review                     Policy renewed             



Wellmark medical policies address the complex issue of technology assessment of new and emerging treatments, devices, drugs, etc.   They are developed to assist in administering plan benefits and constitute neither offers of coverage nor medical advice. Wellmark medical policies contain only a partial, general description of plan or program benefits and do not constitute a contract. Wellmark does not provide health care services and, therefore, cannot guarantee any results or outcomes. Participating providers are independent contractors in private practice and are neither employees nor agents of Wellmark or its affiliates. Treating providers are solely responsible for medical advice and treatment of members. Our medical policies may be updated and therefore are subject to change without notice.

*Current Procedural Terminology © 2012 American Medical Association. All Rights Reserved.

Contact Information
New information or technology that would be relevant for Wellmark to consider when this policy is next reviewed may be submitted to:
  Wellmark Blue Cross and Blue Shield
  Medical Policy Analyst
  P.O. Box 9232
  Des Moines, IA 50306-9232
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