Structural analysis of hip implants designed with triply periodic minimal surfaces (TPMS)

Triply periodic minimal surface (TPMS) lattice structures represent a novel approach in orthopedic implant design by offering a unique balance between mechanical strength and biological compatibility. This study aims to explore the application of TPMS-based porous architectures, specifically gyroid, diamond, schwarz, split-p configurations, in the design of hip implants. A dense hip implant model was initially created using SolidWorks, and later modified in nTopology to incorporate TPMS lattice infill. Two design strategies were implemented: one involving variation in unit cell size while keeping strut thickness constant, and the other involving variation in strut thickness with fixed unit cell size. Static structural analyses were performed via finite element simulations under defined boundary conditions, using the isotropic material properties of magnesium alloy AZ91. Simulation outcomes were evaluated in terms of maximum displacement, von Mises stress, and strain. The results indicate that TPMS-filled implants can significantly reduce weight while maintaining structural integrity, offering improved stress distribution and enhanced potential for osseointegration. This thesis provides a comprehensive analysis of TPMS lattice structures from a mechanical and biological performance perspective, and supports their future integration into patient-specific orthopedic implant designs through additive manufacturing technologies.