The effect of functionally graded materials on bone remodeling around osseointegrated trans-femoral prostheses

Osseointegrated trans-femoral fixations have been used as alternatives for conventional sockets in recent years. Despite numerous advantages, the dissimilarity of the mechanical properties between bone and implant has led to issues in periprosthetic bone adaptation. This study aims to address these issues by proposing fixations made of functionally graded materials (FGMs). The computational study of bone remodeling was performed by linking a bone remodeling algorithm to the finite element analysis. The 3D model of the femur was created by computerized tomography (CT) scan images, and a Titanium fixture, along with nine Titanium/Hydroxyapatite FGM fixtures, were modeled. The analyses revealed evident advantages for the FGM fixtures over the conventionally used Titanium fixtures. Furthermore, it was shown that the gradation direction considerably affects the bone adaptation procedure. The results showed that using a radial FGM with low-stiffness material in the outer layer and less metal composition significantly improves the bone remodeling behavior.