Femoral Mechanical Response in Golfers with Total Hip or Hip Resurfacing Implants

Abstract

This work investigates the stress response in the femur bone which has been modified to accommodate either a total hip replacement or hip resurfacing implant when the hips are subjected to peak loads during a golf swing. The objective is to provide a quantitative comparison of the stress shielding effects of both systems in order to support orthopedic recommendations regarding hip replacement or resurfacing for golfers. The peak loads of a golf swing are determined by applying kinematic relationships and Euler's equations to the lead leg using lead knee and ground reaction force data taken from existing literature. These loads are then applied to 3D Finite Element (FE) static models for the unmodified femur, the femur with a total hip implant, and the femur with a hip resurfacing implant. The FE models predict that both implants will result in significant Von Mises stress reductions along closed paths on proximal and distal femoral transverse planes, compared to normal bone. The Von Mises stress response of the implant systems do not differ by more than 7% for peak or mean stress magnitudes and gradients. FE predictions therefore indicate that, along closed contours, the stress shielding effects from each system may not differ significantly.