Triply periodic minimal surfaces (TPMS) based lattice structure to reduce stress shielding effect

At present, there is a still pressing need for biomaterials that could both stimulate the growth of bone tissue and mitigate the stress shielding effect. Balancing the combination of desirable relative density and promising mechanical property remains challenging in the design of bone scaffolds. In this study, a novel strategy of designing triply periodic minimal surfaces (TPMS) gyroid based lattice structures to reduce the stress shielding effect while maintaining relative density is proposed. The method to generate gyroid structures is discussed, and the relationship between the level-set value and the relative density is evaluated. A finite element model is developed to investigate the elastic properties of gyroid structures at various relative densities. A relationship between its elastic properties and relative density is established. A composite structure based on changing the relative density at different regions to mimic the structure of human bone is introduced, while three different designs are investigated based on the finite element model developed. The results show that lattice structure based on gyroid can reduce the stress shielding effect. Overall, the results presented in this study could provide helpful information for future designs of orthopedic implants.