Abstract
Introduction: There is a great deal of interest in intervertebral disc arthroplasty. These devices have been used in Europe for more than 10 years. There have been several reports published on the European results when using the SB Charité III (link) prosthesis and good results have been reported in 63% to 79% of patients1,2,3. The purpose of this prospective study was to evaluate surgical outcome following implantation of an artificial disc.
Methods: The SB Charité III device has two cobalt chromium plates with a polyethylene core between them. Motion occurs through articulation between the concave/convex surfaces of the plates and core. The disc prosthesis is implanted using the same approach as used for anterior lumbar interbody fusion procedures. It comes in multiple sizes to accommodate variations in individual patient size.
The disc has been implanted in 39 patients in our clinic. This group includes 19 males and 20 females (mean age 39.8 years, range 26 to 54 years). The primary study inclusion criteria were single-level symptomatic disc degeneration, failure of at least six months of non-operative treatment, and no previous surgery at the operated segment. Outcome measures included neurological examination, radiographic assessment, Oswestry Low Back Pain Disability Questionnaire, visual analog scale (VAS) assessing pain, SF-36, and work status. Data were collected pre-operatively, and at six weeks, three, six, and 12 months post-operatively. To date, 22 patients have reached the 12 months follow-up point.
Results: Overall, patients demonstrated improvement in the self-reported outcome measures. The mean VAS score improved approximately 50% at the six weeks follow-up and this improvement was maintained during subsequent follow-up. The Oswestry scores improved 37% at six weeks follow-up and had improved by 50% at subsequent follow-ups. Radiographic assessment revealed no cases of device displacement or migration. Complications were comparable to those reported for anterior lumbar interbody fusion. There have been no cases of device failure.
Discussion: The results of this prospective study, using patient self-report questionnaires, demonstrated good clinical outcome. There was a significant improvement noted six weeks post-operatively that was maintained during the follow-up visits. The disc prosthesis can be implanted safely, with complications similar to those encountered with anterior lumbar interbody fusion. As with any surgical procedure, long-term prospective follow-up is needed and data will be collected as these patients reach 24 months follow-up.
The abstracts were prepared by Dr Robert J. Moore. Correspondence should be addressed to him at The Spine Society of Australia, Institute of Medical and Veterinary Science, The Adelaide Centre for Spinal Research, Frome Road, Adelaide, South Australia 5000
References:
1 Cinotti G, David T, Postacchini F. Results of Disc Prosthesis After a Minimum Follow-up Period of 2 Years, Spine21:995–1000, 1996 Google Scholar
2 LeMaire JP, Skalli W. et al. Intervertebral Disc Prosthesis, Clin Orthop, 337:64–78, 1997 Google Scholar
3 Zeegers WS, Bohnen LM., Laaper M, Verhaegen MJA. Artificial Disc Replacement with the Modular Type SB Charité III, Europ Spine J, 8:210–217, 1999 Google Scholar
