Material selection of acetabular component in human hip prosthesis using finite element concepts

Hip joint replacement is an important issue in orthopaedic surgery. The success of the artificial hip replacement depends upon proper material selection, structure and shape of the prosthesis. Many orthopaedic analyses have been tried with different materials, but ended with partial success on the application side. The main objective of this paper is to extend the acetabular component finite element model of human hip prosthesis to investigate the maximum von Mises stress, contact pressure, contact radius and mean contact pressure to yield strength ratio for different combinations of bio-compatible materials. Eight different geometrical parameters are considered in the current study. The materials used are Co-Cr alloy, Co-Cr-Mo alloy, ultra high molecular weight polyethylene (UHMWPE) and alumina. To guarantee good clinical results in total hip replacement (THR), it is predicted from this extensive analysis that cobalt chromium paired with UHMWPE provides optimum performance in all the conditions. The analysis demonstrates that the implant with larger head radius, cup radius, and UHMWPE cup thickness with decrease in radial clearance value yields better mechanical performance. The finite element results are also compared with the experimental data of Jin et al. (1999) and found to be in good agreement with each other.