Finite-element Analysis of Load-bearing Hip Implant Design for Additive Manufacturing

This research aims to determine the most suitable lattice structure pattern, density, and design space to achieve mass reduction and improve the design of hip implants for additive manufacturing. Additive manufacturing enables the design and manufacturing of complex parts such as lightweight high-strength lattice structures. However, the integration of lattice structures in bone-implant designs and the choice of lattice structure types, densities, and design space are yet to be fully understood. The methodology consists of designing hip implants with different design spaces, lattice types, and densities. Finite-element analysis simulations were conducted on different lattice structure configurations, Cubic FBCCz, and Octet-truss lattice structures with 15, 20, 25, and 30% densities. A 7 kN force is applied to test for implant survivability for various severe loading scenarios on the hip joint to avoid failure and ensuring structural integrity. The results show that the highest deformation observed is the Cubic FBCCz at 15% volume fraction in design space 3. The hip implant integrated into design space 2 with a 25% volume fraction of Octet-truss lattice structure is the most suitable design. In Conclusion section, the most suitable lattice structure for the hip implant is the Octet-truss with a 25% volume fraction in design space 2. The mass for the solid bone implants is 0.331 kg, while the mass for the Octet-truss 25% design space 2 is 0.26 kg. The proposed pattern and density can contribute to the early stages of a design process before experimental works, which should be of broad interest to the biomedical industry for improved hip implant designs with improved osseointegration and user-customized implants.