Computational Analysis and Design of a Triply Periodic Minimal Surface-Based Biomimetic Femoral Stem Implant

Total hip arthroplasty (THA) is widely used to treat end-stage hip disorders; however, conventional solid femoral stems often lead to stress shielding, aseptic loosening, and inadequate bone ingrowth. This study introduces a biomimetic femoral stem based on triply periodic minimal surface (TPMS) architecture to enhance mechanical compatibility and biological integration. Six TPMS topologies were evaluated through homogenization, from which Gyroid and Lidinoid structures at 30% relative density were selected for their modulus compatibility with trabecular bone and high porosity favorable for osseointegration. Finite element simulations indicated significantly improved load transfer, with Gyroid and Lidinoid stems exhibiting higher internal stress distribution (177.91 MPa and 204.04 MPa) compared to the solid stem (3.74 MPa), thereby reducing stiffness mismatch and mitigating stress shielding. Additionally, computational fluid dynamics analysis identified that a Gyroid stem with permeability in the range of 1.2 0 × 10^-5 to 1.18 × 10^-5 m² supports enhanced perfusion conducive to early vascularization. Overall, this work presents a systematic design-to-function optimization pathway that unifies mechanical performance and biological viability, advancing the development of next-generation femoral stem implants for THA.