Authors' objectives:

The objective of this Assessment is to review the available evidence to determine if artificial vertebral disc replacement is an effective treatment for chronic degenerative disc disease (DDD).

Authors' recommendations: Based on the available evidence, the Blue Cross and Blue Shield Medical Advisory Panel made the following judgments about whether the artificial disc for treatment of degenerative disc disease meets the Blue Cross and Blue Shield Association Technology Evaluation Center (TEC) criteria. 1. The technology must have final approval from the appropriate governmental bodies. - In October 2004, the U.S. Food and Drug Administration (FDA) granted Premarket Application (PMA) approval for the Charit Artificial Disc, stating that the device is indicated for spinal arthroplasty in skeletally mature patients with DDD at one level from L4-S1. DDD is defined as discogenic back pain with degeneration of the disc confirmed by patient history and radiographic studies. As a condition of approval, the manufacturer has agreed to conduct a postapproval study, using a maximum of 366 patients (201 randomized investigational subjects, 67 training investigational subjects, and 98 control subjects). Postapproval study patients will be evaluated for a period of 5 years post-implantation. 2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes. - Current evidence supporting the effectiveness of artificial vertebral disc is insufficient. Case series evidence is inadequate to establish efficacy. There is only one completed randomized, clinical trial that evaluates the Charit artificial disc compared to BAK fusion cage. No other disc replacements have better or more rigorous evidence of efficacy. The only randomized, controlled trial has several methodologic issues that make it difficult to interpret the results. The Charit artificial disc had a success rate of 63%, compared to a success rate of 53% for BAK fusion, using a composite measure of outcome that incorporated improvement of symptoms and absence of complications. The first concern is that the analysis showed noninferiority compared to BAK fusion using the composite measure of success, but did not show statistically significant superiority in most outcome measures. A noninferiority trial design implies that there is a trade-off between efficacy outcomes and some other advantage of a new technology, for example, morbidity or invasiveness, such that a less-stringent threshold for efficacy is acceptable. However, at this time, no such advantage has been demonstrated for the Charit artificial disc. So the reported success rate shows that the artificial disc is not inferior to the BAK procedure, not that it is better. The second concern is that the lack of a prespecified analysis plan, unexplained closure of the database before all patients reached completion, and lack of intent-to-treat analysis may cast some doubt on the analysis. Although the sponsor provided TEC with additional analysis that included patients that were excluded from the analysis presented to the FDA, it was unclear how many additional patients actually provided 24-month outcome data and what imputation was performed for missing or discontinued data. Finally, although fusion is considered a standard surgical treatment for back pain due to DDD, doubts remain about its effectiveness, as clinical trials comparing fusion to nonsurgical alternatives show conflicting results. Moreover, substantial variation in frequency, success, reoperations, and complications has recently been reported for spinal fusion procedures. The use of the BAK procedure as a comparator to the Charit disc highlights the problem, as no randomized, controlled trials exist comparing the BAK to other spinal fusion techniques or to conservative management. Given the broader clinical context, and the concerns with the sole randomized, controlled trial, the evidence is not sufficient to conclude that the use of artificial vertebral disc improves health outcomes. Low back pain is a common condition. Given the population affected, additional and more rigorous trials of the outcomes of the use of artificial disc in the treatment of DDD are needed. 3. The technology must improve the net health outcome; and 4. The technology must be as beneficial as any established alternatives. - The evidence is insufficient to determine whether the use of artificial vertebral discs improves the net health outcome or whether they are as beneficial as any established alternatives. 5. The improvement must be attainable outside the investigational settings. - Whether the use of artificial vertebral discs improves health outcomes has not been established in the investigational settings. Therefore, the use of artificial vertebral discs for degenerative disc disease does not meet the TEC criteria.

Authors' methods: Review

Project Status: Completed

URL for project: http://www.bcbs.com/blueresources/tec/contact-tec.html

Year Published: 2005

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: BlueCross BlueShield Association

Contact Address: BlueCross BlueShield Association, Technology Evaluation Center, 225 North Michigan Ave, Chicago, Illinois, USA. Tel: 888 832 4321

Contact Name: tec@bcbsa.com

Contact Email: tec@bcbsa.com

Copyright: BlueCross BlueShield Association (BCBS)