DESCRIPTION
These interspinous implants aim to restrict painful motion while otherwise enabling normal motion. The devices (spacers) distract the 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. Other types of posterior dynamic stabilization devices are pedicle screw/rod-based devices and total facet replacement systems.
The 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 the 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.
An example of this device is the X STOP. In November 2005, the X STOP® Interspinous Process Decompression System (Kyphon) was approved by the U.S. 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.”
Other examples of this device have been used outside the United States. The Wallis System (Abbott Spine) was introduced in Europe in 1986. The Wallis System is currently being tested in a FDA-regulated clinical trial. Also in a FDA-regulated clinical trial is the DIAM Spinal Stabilization System (Medtronic Sofamor Danek).The DIAM system requires removal of the interspinous ligament, and is secured with laces around the upper and lower spinous processes.
POLICY
The implantation of an interspinous distraction device for the treatment of pain associated with degenerative disc disease is considered investigational.
IMPORTANT REMINDER
We develop Medical Policies to provide guidance to Members and Providers. This Medical Policy relates only to the services or supplies described in it. The existence of a Medical Policy is not an authorization, certification, explanation of benefits or a contract for the service (or supply) that is referenced in the Medical Policy. For a determination of the benefits that a Member is entitled to receive under his or her health plan, the Member's health plan must be reviewed. If there is a conflict between the Medical Policy and a health plan, the express terms of the health plan will govern.
ADDITIONAL INFORMATION
Well-designed, randomized, controlled trials with long-term follow-up are not available to determine long-term benefits of interspinous distraction devices (spacers) for the treatment of pain associated with degenerative disc disease compared to alternative treatments.
SOURCES
BlueCross BlueShield Association. Medical Policy Reference Manual. (5:2009). Interspinous distraction devices (spacers) (7.01.107). Retrieved June 1, 2010 from BlueWeb. (13 articles and/or guidelines reviewed)
ECRI Institute. Health Technology Information Service. Emerging Technology (TARGET) Evidence Report. (2007, September). Interspinous process decompression to treat spinal stenosis. Retrieved January 10, 2008 from ECRI Institute. (9 articles and/or guidelines reviewed)
Health Technology Assessment Information Service. Target Report 914. (2006, November). Interspinous process decompression to treat spinal stenosis. Retrieved December 12, 2006 from ECRI HTAIS.
Verhoof, O.J., Johannes, L.B., Wapstra, F.H., van Royen, B.J. (2008). High failure rate of the interspinous distraction device (X-Stop) for the treatment of lumbar spinal stenosis caused by degenerative spondylolisthesis. European Spine Journal, 17 (2), 188-192.
Zucherman, J. F., Hsu, K. Y., Hartjen, C. A., Mehalic, T. F., Implicito, D. A., Martin, M. J., et al. (2005). 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, 30 (12), 1351-1358.
ORIGINAL EFFECTIVE DATE: 4/12/2007
MOST RECENT REVIEW DATE: 7/22/2010
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Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.
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