Finite element analysis of biodegradable Ti/polyglycolic acid composite bone plates based on 3D printing concept

Abstract

Dense metallic bone plates often cause stress shielding, delayed healing, or bone non-unions. Therefore, three-dimensional models of partially biodegradable titanium/polyglycolic acid (Ti/PGA) composite cubes with strut thicknesses of 0.33–1.25 mm were designed to achieve different mechanical properties, and compressive simulations of these models were performed to construct stress–strain plots. Finite element models of these plates were assembled with tibial bone fractures using six bicortical screws. Callus volumes were predicted using a rejection coefficient algorithm, and a mechanoregulation algorithm based on deviatoric strain and fluid flow was employed to simulate the healing process. The effective Young’s moduli were 12.13–84.6 GPa during the first week and 4.4–80 GPa during the sixth week, while the callus volume increased after reducing the Young’s modulus of the bone plate. Thus, the additively manufactured design of biodegradable bone plates can be controlled to achieve the appropriate initial Young’s modulus and degradation rate.