Wear Evaluation of Crosslinked UHMWPE for Knee Prostheses Using a Multi-Station Rolling-Sliding Tribotester

Tribology-related failure of total knee replacement prostheses can lead to risky and expensive revision surgery. Recent changes in polyethylene processing may reduce the incidence of, or even eliminate contact fatigue failure related to bearing oxidation, but devices are still subject to failure modes relating to wear or non-oxidation related fatigue. Contemporary materials claim wear reduction and improved oxidation resistance through various crosslinking and annealing steps, but clinical wear performance of these materials in the knee is difficult to determine. A device incorporating clinically relevant motions and stress states has been used in this work to compare the wear properties of crosslinked polyethylene materials subjected to different irradiation and sterilization conditions. It can potentially be used to analyze the wear behavior of polyethylene materials from different manufacturers, allowing for better prediction of relative performance in vivo.