Biomechanical Analysis of Multi-Material Hip Implant Assembly

Abstract

In present work, a 3D multi-material Charnley’s femoral stem with standard geometry model, i.e., 28mm diameter femoral head and 2mm thick liner, has been developed and analyzed for mechanical behavior like stress, strain, and deformation. An axial load of 2.3kN has been used to analyze for twelve multi-material combinations of CoCr and Ti materials for stem, with three femoral head ceramics materials (alumina, zirconia, and ZTA) and UHMWPE for liner. These mechanical parameters are also well validated with published literature and have been evaluated for investigating the functionality and suitability of biomaterials. Changing the femoral head does not make any significant impact on the mechanical parameters. The preliminary simulation result demonstrates that CoCrMo with Zirconia and UHMWPE demonstrates the most minimum deformation and maximum stress generation. However, CoCrMo leads to modulus mismatch due to its very high modulus. So, implant with less deformation and moderate stress, i.e. Ti-6Al-7Nb is preferred over CoCrMo.