Adaptive Bone Remodeling to Capture the Trabecular Bone Morphology of the Proximal Femur

Abstract

In this study, a model of femur which resembles bone natural structure has been developed. The model initially consists of a solid shell representing cortical bone encompassing a cubical network of interconnected rods with circular cross-sections representing trabecular bone part. A computational efficient program has been developed which iteratively changes the structure of trabecular bone by keeping the local stress in the structure within a defined stress range. The stress is controlled by either enhancing existing beam elements or removing beams from the initial trabecular frame structure. Trabecular bone structure is obtained for two load cases: walking and stair climbing. The results show that as the magnitude of the loads increase, the internal structure gets denser in critical zones. The higher density is achieved using loading associated with the stair climbing. Walking which is considered as the routine daily activity, results in the less internal density in different regions of the bone. The results show that the converged bone architecture consisting of rods and plates are consistent with the natural bone morphology of femur. Furthermore, the bone volume fraction at the critical regions of the converged structure is in a good agreement with previously measured data obtained from combinations of Dual X-ray Absorptiometry (DXA) and Computed Tomography (CT).