THREE-DIMENSIONAL SHAPE OPTIMIZATION OF FEMORAL COMPONENT OF HIP PROSTHESES WITH NONLINEAR FRICTIONAL INTERFACE

A numerical procedure was implemented for the three-dimensional shape optimization of femoral component of total hip replacements. An algorithm was developed for defining the component geometry in terms of longitudinal and cross-sectional shape variables. The three-dimensional design model was combined with a non-linear 3-D finite element analysis and a numerical optimization procedure. An idealized femoral geometry and a frictional contact were used for bone-implant interfaces. The design objective was to reduce the shear stresses and the relative motion between implant and the surrounding bone along the interface region. The general trend in all design optimization was to produce a somewhat bulky implant with a more rectangular cross section. The outcome was more strongly affected by interface condition than choice of objective function.