Abstract

This study aims at observing the effects of loading conditions in loosening behavior of acetabular cup using Finite Element Analysis (FEA). Number of total hip replacement (THR) has been increasing in super-aging society like Japan. Service lives of hip joints are limited by loosening behavior and loosening occurs by either, biological, chemical and mechanical factors. However, it is very difficult to identify the contributions of each factor in the loosening behavior in vivo, and then FEA was applied to simulate the loosening behavior owing only to mechanical loading. 3-dimensional FEA model was developed and the effect of bonding conditions between acetabular cup and bone was considered. Only in the case of shear stress breaking bonding, the contact was partially broken, which led to large displacement of 100 μm. Such the relative displacement at the interface can be a critical factor of worsening the value of loosening.