Medical Policy: 07.01.35
Original Effective Date: January 2007
Reviewed: February 2016
Revised: February 2016
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 Distraction Devices
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.
Interspinous Fixation Devices
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 are also being evaluated for stand-alone use in
patients with spinal stenosis.
Interspinous fixation (fusion) devices contrast with interspinous distraction devices (spacers), which are used alone for decompression and are typically not fixed to the spinous process. In addition, whereas interspinous distraction devices may use dynamic stabilization, interspinous fixation devices are rigid. However, the fixation devices might also be used to distract the spinous processes and decrease lordosis. Thus, the fixation devices might be used off-label without interbody fusion as decompression (distraction) devices in patients with spinal stenosis. If fixation devices are used alone as a spacer, there is a risk of spinous process fracture.
For use in combination with fusion, it is proposed that interspinous fixation systems are less
invasive and present fewer risks than pedicle or facet screws. However, while biomechanical studies indicate 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 interspinous device. There is also a potential for spinous process fracture. Given these uncertainties, studies are needed that compare health outcomes between interspinous fixation devices and pedicle screw-rod fixation.
The following interspinous fixation devices have received clearance to market by the U.S. Food and Drug Administration (FDA):
The North American Spine Society
The North American Spine Society (NASS) issued a coverage position on the use of interspinous devices with lumbar fusion. NASS recommends that interspinous fixation with fusion for stabilization is currently not indicated as an alternative to pedicle screw fixation with lumbar fusion procedures.
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.
Interspinous Fixation Devices
Interspinous fixation devices are considered investigational for any indication, Including but not limited to use:
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.