This policy addresses the use of the Dynesys® Dynamic Stabilization Spinal System and the SATELLITE™ Spinal System, which have been proposed as an adjunct to spinal fusion procedures to provide immobilization and stabilization of spinal segments.

Investigational/Not Medically Necessary:

Use of the Dynesys® Spinal System is considered investigational/not medically necessary for all indications.

Use of the SATELLITE™ Spinal System is considered investigational/not medically necessaryfor all indications.

Dynesys® Dynamic Stabilization Spinal System

Putzier, et al (2005) looked at the effect of dynamic stabilization on the progression of vertebral segment degeneration after nucleotomy of the lumbar spine for symptomatic disc prolapse.  A total of 84 patients were studied and dynamic stabilization with the Dynesys® system was performed in 35 patients.  Patients were evaluated with MRI and subjective evaluation using Oswestry and VAS pain scores at three months and again at final follow-up (mean duration of follow-up of 34 months).  Oswestry score and VAS improved significantly in both groups to the same degree at 3 months.  At the end of follow-up, VAS pain scores worsened for the control group (P<0.05), but not for the group with dynamic stabilization.  In the dynamically stabilized group, no progression of disc degeneration was seen at follow-up, while radiologic signs of segmental degeneration were seen in the patients not provided dynamic stabilization post nucleotomy.  Although the authors concluded that the Dynesys system is useful to prevent progression of degenerative disc disease following nucleotomy, this study was non-randomized and the treatment group was retrospectively compared with patients treated only with nucleotomy before the availability of the Dynesis® system.

Grob (2005) reported the results of a retrospective case series study of patient outcomes after implantation of the Dynesys® Spinal System.  A total of 50 consecutive patients instrumented with Dynesys over the preceding 40 months were asked to complete a patient-oriented follow-up questionnaire.  31 patients responded with at least two  years of follow-up.  Primary indication for surgery was degenerative disease (disc/stenosis) with “instability”.  In 68% of the patients more than one level was instrumented.  Within the 2-year follow-up period, 19% required further surgical intervention.  Back pain was reported improved (67%) and leg symptoms were improved (64%) or worse (14%).  40% improved in their ability to do physical activities/sports while 27% worsened.  Overall quality of life 50% improved, 13% worse.  When asked how much the operation helped, 29% reported helped a lot and 35% reported didn’t help at all.  Pre-operative VAS pain intensity scores could not be compared with scores at follow-up due to methodological differences.  Six of 31 patients either required reintervention in the 2-year follow-up or were undergoing evaluation for re-operation in the near future.  The investigators concluded that both back and leg pain are, on average, moderately high 2 years after instrumentation with the Dynesys® system and that overall patient oriented results were poorer than those for historic controls undergoing fusion for similar indications at their center.  The investigators felt there is insufficient evidence to suggest that semi-rigid fixation of the lumbar spine results in better patient-oriented outcomes than does fusion.

More recently, Schnake and colleagues (2006) report on a small prospective case series study consisting of 26 patients (mean age 71 years) with lumbar spinal stenosis and degenerative spondylolisthesis.  Patients underwent decompression and dynamic stabilization with the Dynesys® system.  The reported minimum follow-up was 2 years.  The authors report significant improvements in leg pain and mean walking distance.  However, a significant number of patients (21%) reported continuing claudication.  No significant progression of spondylolisthesis was detected, but an implant failure rate of 17% was reported.  The authors conclude that results with the Dynesys® device were comparable to clinical results seen with standard fusion techniques.  They do acknowledge that the study is limited by a small number of patients, short follow-up, and lack of randomized controls.

The European National Institute for Health and Clinical Excellence (NICE, 2005) systematic evidence review of non-rigid stabilization procedures for the treatment of low back pain concluded that “current evidence on the safety of these procedures is unclear and involves a variety of different devices and outcome measures.  Therefore, these procedures should not be used without special arrangements for consent and for audit or research”. 

The Dynesys® Spinal System (Centerpulse Spine-Tech, Inc. Minneapolis, MN) was cleared by the US Food and Drug administration (FDA) via a 510(k) clearance March 2004.  This type of approval does not involve extensive clinical trial data submission and review by the FDA.  In order to qualify for a 510(k) clearance a manufacturer need only prove that their device is similar in function to a device that had previously been granted FDA approval for interstate commerce prior to May 28, 1976.  The product’s label indicates the device is “to provide stabilization of spinal segments in skeletally mature patients as an adjunct to fusion in the treatment of chronic instabilities or deformities of the thoracic, lumbar, and sacral spine.”  Indications include degenerative spondylolisthesis with objective neurologic impairment, kyphosis, and failed previous fusion (pseudoarthrosis).  In addition, the product labeling states the Dynesys system is intended for use in persons also meeting all of the following criteria:

• Patients who are receiving fusions with autologous graft only; and
• who are having device attached to the lumbar or sacral spine; and
• who are having the device removed after the development of a “solid fusion mass”

In summary, although this device has been in clinical use for several years, there is insufficient evidence that the use of this device results in improved health outcomes compared to standard treatments.  It is not possible to establish a health outcome benefit for this device due to insufficient data from prospective, randomized controlled clinical trials for the FDA approved indications.

The Dynesys® Spinal System has also been proposed for immobilization and stabilization of spinal segments without a spinal fusion procedure.  To date, such use has not been approved by the FDA.

SATELLITE™ Spinal System

The SATELLITE™ Spinal System consists of spheres manufactured from either cobalt chrome or medical grade PEEK-OPTIMA LTI. According to the product label, this device is designed to be inserted between the vertebral bodies into the disc space from L3 to SI to facilitate stabilization and to support intervertebral body fusion. The SATELLITE™ Spinal System is intended for, and designed solely for holding bone parts in alignment while they heal. The SATELLITE™ Spinal System is intended to be used with bone graft.

While the SATELLITE™ Spinal System has received 510(k) premarket approval from the FDA as a device to provide intervertebral stabilization, at the time of this review, there are no published peer-reviewed scientific studies addressing the use of this device in humans. Therefore, there is no data available from which to draw conclusions about the safety and efficacy of this device at this time.

Spondylolisthesis is a condition in which a back bone (vertebra) slips forward on the vertebra below it. In adults, the most common cause is degenerative arthritis involving the fourth and fifth lumbar vertebrae.  Other causes of spondylolisthesis include spinal fracture.  Spondylolisthesis may occasionally be associated with bone diseases.  Symptoms may include lower back pain and pain in the thighs and buttocks, stiffness, muscle tightness, and spinal tenderness.  Neurologic damage (leg weakness or sensory changes) may result from pressure on nerve roots and may cause pain radiating down the legs.

Treatment varies depending on the severity of the spondylolisthesis. Most patients require only strengthening and stretching exercises combined with activity modification (avoiding hyperextension of the back and contact sports). Some practitioners may also use a rigid brace.

For cases with severe pain not responding to therapy, if the slip is severe, or there are neurologic changes (loss of feeling in the legs, etc), the slipping vertebra might be surgically fused to adjacent vertebrae to prevent further slippage and provide relief of symptoms.

Fusion procedures involve placement of a bone graft or equivalent substance into the joint space after removal of the intervertebral disc as well as attachment of a rigid metal frame to adjacent vertebral bodies. The frame is used to hold the joint in place while the joint space fuses over time. As a result of fusion surgery, there is a subsequent loss of mobility where the intervertebral joint once was.  This loss of mobility has been associated with increased loading on adjacent joints and potential complications related to failure of those joints.

In an attempt to overcome the disadvantages of rigid instrumentation and improve the outcome of spinal fusion surgery, the Dynesys® Spinal System (Centerpulse Spine-Tech, Minneapolis, Minnesota) has been proposed as an alternative to the use of standard rigid frames.  Like standard frame devices, the Dynesys® Spinal System is fixed in place using pedicle screws which are attached to the vertebral bodies adjacent to the intervertebral space being fused.  Unlike standard frames, the Dynesys® Spinal System is designed using flexible materials which stabilize the joint while still providing some measure of flexibility.  The Dynesys® is installed posteriorally and does not require bone to be taken from the hip, as is required in other fusion procedures.

The following codes for treatments and procedures applicable to this policy are included below for informational purposes.  Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy.  Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services are Investigational/Not Medically Necessary:

When the code describes a procedure indicated in the Policy section as investigational/not medically necessary.

CPT

ICD-9 Procedure

ICD-9 Diagnosis

Peer Reviewed Publications:

1. Grob D, Benini A, Junge A, Mannion AF. Clinical experience with the Dynesys semirigid fixation system for the lumbar spine: surgical and patient-oriented outcome in 50 cases after an average of 2 years. Spine. 2005; 30(3):324-331.
2. Putzier M, Schneider SV, Funk JF, et al. The surgical treatment of the lumbar disc prolapse: nucleotomy with additional transpedicular dynamic stabilization versus nucleotomy alone. Spine. 2005; 30(5):E109-114. 
3. Schnake KJ, Schaeren S, Jeanneret B.  Dynamic stabilization in addition to decompression for lumbar spinal stenosis with degenerative spondylolisthesis. Spine. 2006; 31(4):442-449.

Government Agency, Medical Society, and Other Authoritative Publications:

1. National Institute for Clinical Excellence (NICE). Interventional procedure overview of non rigid stabilisation techniques for the treatment of low back pain. November 22, 2005. Available at:  http://www.nice.org.uk/page.aspx?o=ip306overview.  Accessed on April 10, 2007.
2. U.S. FDA. 510K approval letter for Dynesys® Spinal System (2005). Available at:  http://www.fda.gov/cdrh/pdf4/k043565.pdf. Accessed on April 10, 2007.
3. U.S. FDA. 510K approval letter for the SATELLITE™ Spinal System (2007). Available at:  http://www.fda.gov/cdrh/pdf6/K060415.pdf.  Accessed on April 10, 2007.

1. National Library of Medicine. Medical Encyclopedia: Spondylolisthesis.  Available at:  http://www.nlm.nih.gov/medlineplus/ency/article/001260.htm. Accessed April 10, 2007.

Dynamic Stabilization
Dynesis® Spinal System
Dynesys® Spinal System
SATELLITE™ Spinal System
Spondylolisthesis

The use of specific product names is illustrative only. It is not intended to be a recommendation of one product over another, and is not intended to represent a complete listing of all products available.
 

Federal and State law, as well as contract language, including definitions and specific contract provisions/exclusions, take precedence over Medical Policy and must be considered first in determining eligibility for coverage. The member's contract benefits in effect on the date that services are rendered must be used. Medical Policy, which addresses medical efficacy, should be considered before utilizing medical opinion in adjudication. Medical technology is constantly evolving, and we reserve the right to review and update Medical Policy periodically. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by an means, electronic, mechanical, photocopying, or otherwise, without permission from the health plan.

©CPT Only - American Medical Association