歩行時における人工膝関節の接触変形解析 : 第2報, UHMWPE 関節板接触面形状の摩耗挙動への影響

抄録

Ultrahigh-molecular-weight polyethylene (UHMWPE) is the material generally used for the articular plate contact surface in artificial knee joints ; however, the wear of this material becomes a serious problem during extended life of the joint. In order to understand the wear mechanism of the plate during gait and to improve its wear life, the cyclic contact behavior of the plate was analyzed using the constitutive equation for cyclic plasticity, since the plate is subjected to cyclic contact deformation during gait. The posterior cruciate ligament (PCL) retention-type artificial knee joint as the basic analytical model, as well as two other modified contact surface models, were analyzed to investigate the effect of the shape of the contact surface on the wear behavior of the plate. As a result, it was clarified that the wear behavior of the plate is closely related to the shape of the contact surface. The optimal design of contact surface is considered using this analysis.