Contact analysis of ultrahigh molecular weight polyethylene articular plate in artificial knee joint during gait movement

To understand the wear mechanism of the ultrahigh molecular weight polyethylene (UHMWPE) articular plate used in artificial knee joints, the cyclic contact behavior of the plate during gait movement was analyzed using the constitutive equation for cyclic plasticity. In this study, two-dimensional plane strain model was employed and the contact behavior of femoral and tibial components was simulated by translating the contact stress distribution which was calculated from elasto-plastic indentation analysis of two components. For analytical model, the anatomical type artificial knee joint was employed and the effect of the shape of contact surface on the wear behavior of the plate was investigated. As a result, it was clarified that the wear of the plate should occur both from the surface and the subsurface of the plate and the wear behavior of the plate should be closely related with the shape of contact surface. Then the optimum shape of contact surface could be designed using this method.