Intervertebral disc arthroplasty.
METHODS
Review article of current knowledge of disc arthroplasty.


OBJECTIVE
To review the rationale for disc replacement, the general principles of design, and early clinical results.


BACKGROUND
Disc arthroplasty is an emerging treatment for patients with disc degeneration. Its theoretical advantages are to maintain motion, decrease the incidence of adjacent segment degeneration, avoid complications related to fusion, and allow early return to function.


METHODS
Literature review of currently implanted prostheses or those undergoing investigation.


RESULTS
At this time, the theoretical advantages are unproven clinically but have been confirmed in biomechanical and kinematic investigations. Multicenter studies of both cervical and lumbar prostheses have shown short-term results equivalent to fusion. Neurologic complications and failures have been rare. Prosthetic subsidence and long-term wear will most likely be potential failure mechanisms. Thus far, with the exception of nucleoplasty, these problems have not been observed.


CONCLUSIONS
The early results are satisfactory, but the basic premise that motion preservation will diminish adjacent segment degeneration is yet unproven. Long-term results are unavailable and failure modes are unknown. Before implantation, the surgeon and patient must understand the experimental nature of the devices.
Anderson
Paul A
PA
Department of Orthopedic Surgery and Rehabilitation, University of Wisconsin, Madison, WI 53972, USA. anderson@orthorehab.wisc.edu
Rouleau
Jeffrey P
JP
D019643:Arthroplasty, Replacement / Q000295:instrumentation / Q000379:methods*; D002574:Cervical Vertebrae / Q000601:surgery; D002986:Clinical Trials as Topic; D006801:Humans; D007403:Intervertebral Disc / Q000601:surgery*; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery; D019637:Orthopedic Procedures / Q000379:methods* / Q000639:trends; D019736:Prostheses and Implants