Stress analysis of normal and osteoarthritic femur using finite element analysis

Stress distribution within the normal and osteoarthritic femur is studied using plane stress finite element analysis. During the progress of osteoarthritis of hip, the resultant load transferred from the acetabulum to the femur, instead of acting over a large area is reduced considerably. Also, the resultant load changes its direction becoming more vertical in advanced stages of the disease. This alters the stress distribution within the femur. Regions of extremely low stresses are observed at the outer layers of the femur head which may cause the bone to atrophy resulting in void formation. As a follow up, we have modelled these voids as stress raisers. Subsequent analysis reveal stress concentration in the immediate neighbourhood of the voids suggesting these areas as potential sites for microfractures which may eventually lead to femoral neck fractures.