4:19 Lumbar disc replacement: 7 to 11-year results with Prodisc

Abstract

Purpose of study: Total disc replacement is a surgical procedure that can be considered as an alternative to spinal fusion, for the treatment of patients with chronic low back pain secondary to degenerative disc disease. Total disc replacement allows pathological disc removal while maintaining or restoring disc height and preserving motion of the involved segment.Methods used: Prodisc is made up of an inferior and superior titanium plate. Each plate has two notched keels designed to provide mechanical interlocking with the vertebral end plate. The surfaces of the plates in contact with bone are plasma sprayed with titanium allowing the bone ingrowth and providing long-term stability. A convex shape dome of polyethylene inserted in the inferior plate articulates with superior plate and allows motion between the vertebral bodies. Patients enrolled in this study had a history of chronic low back pain and had failed conservative therapy. Patients were clinically evaluated for low back pain and leg pain using a visual analog scale (VAS); neurological examination and the use of pain medication. Patients were interviewed on daily activity, work recovery, sport, and the Oswestry scale and Short Form (SF)-36 were recorded. Preoperative and follow-up Beaujon score, including evaluation of low back pain, leg pain, neurological status, walking capacity, medication and everyday life evaluation, were compared. Radiographs and computed tomography scans were evaluated. Radiographic measurement included height of implant, resorption around the implant, flexion/extension and lateral bending motion and subsidence.of findings: From 1990 to 1993, 93 prostheses were implanted in 64 patients by anterior approach from L2 to S1: 39 cases, one level; 21 cases, 2 levels; 4 cases 3 levels. To date, no implants have been explanted. Five patients with ongoing pain have been fused by a posterior approach. Radiographically, all implants are stable and show no migration of subsidence. The last follow-up patients were at 8.6 years average of postsurgery. Complications included vascular (1) and sexual temporary dysfunction (2) and were related to the anterior approach. The patients' back pain measured by VAS was on average 8.5 preoperatively and 3.0 at the final follow-up. For leg pain, VAS showed 7.1 preoperatively and 1.9 at the final follow-up. At the long-term follow-up, 65% of the patients reported that they were “entirely satisfied,” 28% “satisfied” and only 7% “not satisfied.” These overall patient satisfaction data were supported by the Oswestry score (average, 8.3) as well as the SF-36 results and Beaujon score (average preoperative 7/20 SD=3, postoperative 16/20 SD=3, relative gain 0.69, SD 0.23).Relationship between findings and existing knowledge: These results demonstrate that the Prodisc can remain mechanically stable and provide significant pain relief and improvement in functional status while maintaining motion in patients at 7 to 11 years of follow-up. Total disc replacement may represent an option for the surgical treatment of mechanical low back pain secondary to degenerative disc disease that removes the pathological disc but preserves motion. Disc arthroplasty constitutes a promising alternative to fusion.Overall significance of findings: It may actually be associated with the development of less adjacent disc disease than an arthrodesis because of the preservation of motion. However, further research is necessary, and a prospective, randomized trial is necessary to compare these two techniques for the treatment of degenerative disc disease.Disclosures: No disclosures.Conflict of interest: Thierry Marnay, consultant, and stockholder: Spine Solutions Inc.