Multiscale stress analysis of trabecular bone around acetabular cup implant by finite element mesh superposition method

Abstract

Microscopic stress was calculated with 0.017 mm resolution in a macroscopic model with approximately 100 mm size using the finite element mesh superposition method. To bridge the large gap in resolution, an intermediate finite element model was newly used. This multiscale computational procedure was applied to the biomechanical problem to analyze the microscopic stress in the trabecular bone around acetabular cup implant in total hip arthroplasty, which occurs by direct contact of the implant with trabecular bone. In the microstructural modeling of highly porous media such as the trabecular bone, special attention was paied to the boundary of microstructure model for both homogenization procedure and mesh superposition procedure. Three demonstrative numerical results revealed that higher stress occured at microscale due to macroscopic stress concentration, which is hardly estimated by only bone volume fraction.