ABSTRACT
The goal of restoring normal painless motion to a joint is not a new concept in orthopedics. Total joint arthroplasty for the hip and knee has been shown to provide excellent pain relief while maintaining motion in scores of clinical studies. In light of the historically wide range of results of fusion for low back pain, and the risk of adjacent segment disease, this concept of motion preservation has been applied to degenerative disc disease of the lumbar spine in four recent large-scale United States Food and Drug Administration (USFDA) clinical trials comparing total disc replacement to spinal fusion. The FDA approved the SB Charite´ III
(DePuy Spine, Raynham, Massachusetts, U.S.A.) prosthesis for single level use in November of 2004 (1). The ProDisc-L
(Synthes Spine, Paoli, Pennsylvania, U.S.A.) trials have also completed enrollment, and a two-year follow-up results are being evaluated prior to FDA approval (estimated early 2006) for single and two-level use. Enrollment for the Maverick
disc (Medtronic, Memphis, Tennessee, U.S.A.) U.S. clinical trials began in the spring of 2003, and the FlexiCore
disc (Stryker Spine, Allendale, New Jersey, U.S.A.) U.S. clinical trials are going on as well.
