Local reactions to wear debris generated by hip and knee replacement devices have been shown to lead to failure of some devices via osteolysis and component loosening. This has not been shown to be a clinical issue with the most widely used spinal artificial disc prostheses, but the because of the proximity of these devices to sensitive neural structures in vivo, the issue deserves examination. The purpose of the present study was to investigate the wear characteristics of a lumbar artificial disc under simulated motion and loading conditions. In vitro testing using a modern joint simulator with loads and motions representative of possible lumbar spine motions show a relatively low polyethylene wear rate out to 10 million cycles with a dependence of resulting wear on input load and motion parameters.
