Stress and damage formation analysis in hip arthroplasties using CT-based finite element method

Femoral neck fractures and prosthesis loosening are several biomechanical concerns in promoting the long term stability of hip arthroplasties. External high impact loading due to sideway falls may contribute to the risk of femoral fractures and joint failures. The purpose of this study is to investigate the biomechanical effects of hip resurfacing and total hip arthroplasty on the resulting stress and damage formation. Four loading conditions are considered in the analysis to represent sideway falls at different configurations. Finite element analysis is performed using CT-based femoral bone model to predict the stress and damage formation in both arthroplasties. Stress shielding effects and potential of femoral fractures are observed in the cortical bone adjacent to the prosthesis. The results show that stress adaptation is predicted at both hip arthroplasties cases which lead to stress shielding problems especially in total hip arthroplasty. The variation of damage formation at trochanteric region suggested for femoral neck fractures and potential of implant loosening in both cases.