[Artificial Disc Replacement] Lumbar Total Disc Replacement: Seven to Eleven-Year Follow-Up

[Justin]

The Journal of Bone and Joint Surgery (American). 2005;87:490-496.

Lumbar Total Disc Replacement: Seven to Eleven-Year Follow-Up

Patrick Tropiano, MD1, Russel C. Huang, MD2, Federico P. Girardi, MD2, Frank P. Cammisa, Jr., MD2 and Thierry Marnay, MD3
1 Department of Orthopaedic Surgery, Hôpital CHU Nord, Chemin des Bourrelly, 13915 Marseille CEDEX 20, France
2 The Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021. E-mail address for R.C. Huang: russelhuang(at)yahoo[dot]com
3 Department of Orthopaedic Surgery, Clinique du Parc, 50 Rue Emile-Combes, Boite Postal 20, 34171 Castelnau-le-Lez, France

Investigation performed at the Department of Orthopaedic Surgery, Clinique du Parc, Castelnau-le-Lez, France

A video supplement to this article is available from the Video Journal of Orthopaedics. A video clip is available at the JBJS web site, www.jbjs.org. The Video Journal of Orthopaedics can be contacted at (805) 962-3410, web site: www.vjortho.com.

In support of their research or preparation of this manuscript, one or more of the authors received grants or outside funding from Spine Solutions. In addition, one or more of the authors received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity (Spine Solutions). No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the authors are affiliated or associated.

Background: Symptomatic lumbar degenerative disc disease is a challenging entity to treat. The results of arthrodesis may be compromised in the short term by pseudarthrosis and in the long term by pain at the iliac-crest donor site and by junctional degeneration. Total disc replacement has the potential to provide long-lasting relief to these patients. The purpose of this study was to present the clinical and radiographic results assessed seven to eleven years following a Prodisc total lumbar disc replacement.

Methods: Sixty-four patients had single or multiple-level implantation of a total lumbar disc replacement between 1990 and 1993. The mean duration of follow-up was 8.7 years. Clinical results were evaluated by assessing preoperative and postoperative lumbar pain, radiculopathy, disability, and modified Stauffer-Coventry scores. Preoperative and postoperative radiographs were evaluated as well. Subgroup analysis was performed to determine if gender, an age of less than forty-five years, previous surgery, or multilevel surgery had an effect on outcome.

Results: At an average of 8.7 years postoperatively, there were significant improvements in the back-pain, radiculopathy, disability, and modified Stauffer-Coventry scores. Thirty-three of the fifty-five patients with sufficient follow-up had an excellent result, eight had a good result, and fourteen had a poor result. Neither gender nor multilevel surgery affected outcome. An age of less than forty-five years and prior lumbar surgery had small but significant negative effects on outcome. Radiographs did not demonstrate loosening, migration, or mechanical failure in any patient. Five patients had approach-related complications.

Conclusions: The Prodisc lumbar total disc replacement appears to be effective and safe for the treatment of symptomatic degenerative disc disease. Gender and multilevel surgery did not affect the outcomes, whereas prior lumbar surgery or an age of less than forty-five years was associated with slightly worse outcomes. Longer follow-up of this cohort of patients and randomized trials comparing disc replacement with arthrodesis are needed.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

© 2005 The Journal of Bone and Joint Surgery, Inc.

[KBear]

That is interesting, I wonder why age of less than 45 would have a worse outcome. Seems like just the opposite would be true. Any ideas why this might be? Maybe more active? Seems like since less than 45 is less likely to be affected by osteoporosis or ostopenia and other age related degeneration, that we would have better outcomes???

[ajj1001]

Could it be that the younger you are the more likely it is that other discs will develop problems as they are squidgier (not sure of the proper term for you discs aging and becoming more solid!)

Under 45's are definitely going to be more active than older recipients so put more demands on the disc and adjacent levels.

[Justin]

Kathy and Alison, I looked at the Appendix to the full-text publication to understand why an age of less than 45 years was associated with slightly worse outcomes. Here's what I found in the appendix:

The postoperative modified Stauffer-Conventry score evaluated the parameters listed below and was statistically significant for the subgroup with an age≥45. The score ranges from 0 (the worst) to 20 (the best). Subjects with an age<45 had a score of 15.1 ± 2.9, while subjects with an age≥45 scored 17.2 ± 2.2.

Parameters:

• Low-back pain
• Radicular pain
• Neurologic deficit
• Medication
• Daily living activities
• Postoperative work status
• Psychiatric status

I hope this helps.