The effect of geometry of prosthesis on the stability of hip joint arthroplasty using finite element method

Abstract

Lack of stability is known as one of the principal factors contributing to the loosening of hip prosthesis. Initial stability of the hip prosthesis is related to the magnitude of relative displacement at the femoral boneprosthesis interface. The present study investigated the effect of prosthesis geometry on the initial stability. In addition, the effect of hole and fin as additional features of prosthesis was also investigated. Three-dimensional (3D) finite element model of femur and prosthesis was constructed based on Computed Tomography (CT) dataset of a Malaysian male patient. Simulations of normal walking condition were performed on the models to investigate the relative displacement between the bone and prosthesis interface. The simulation results showed that rectangular hip prosthesis contributed to the reduction of relative motion at the proximal and distal ends of the prosthesis. For the prosthesis with additional hole as a feature on the proximal region of prosthesis, the result showed that it increased the magnitude of relative displacement at the proximal region on the medial side. For the effect of fin, it was observed that the relative displacement was lower than 40 µm along the lateral and medial sides.