Evaluating the performance of hollow stems used in total hip replacement by 3D finite element analysis

A 3D finite element analysis is carried out to evaluate the performance of our different developed hollow stems compared to the classical solid one. The hollow stems were developed considering the topology and shape optimization. Three types of optimized hollow stems were provided: KAD (Kharmanda-Antypas-Dyachenko) stem with a single hole, OAM (Optimized Austin-Moore) stem with double holes and IAM (Improved Austin-Moore) stem with three holes. A multi-objective formulation was developed as a performance scale for all kinds of studied stems (solid and hollow). This study is carried out according to the daily loading cases and considering that all used components (ball, stem, cortical and cancellous) are assumed to be made of isotropic and homogeneous materials. In the numerical applications, it is first shown the significant advantage of the three hollow stems compared to the solid one considering a performance function scale. Next, when comparing all hollow stems (KAD, OAM and IAM) in details, it is shown that the KAD stem for the daily loading cases, leads to the most homogeneous von-Mises stress distribution in both cortical and cancellous tissues