Topological optimization of hip spacer reinforcement

The use of an antibiotic-enriched hip spacer represents the optimal treatment for periprosthetic joint infections (PJI). The addition of reinforcement significantly enhances its mechanical properties. Employing the explicit method enables accurate prediction of the mechanical behavior of both the spacer and its reinforcement. Topological optimization of the reinforcement emerges as the most effective strategy to prevent bone demineralization, enhance antibiotic diffusion, and improve spacer resistance. The objective of this study is to conduct topological optimization of a validated numerical model of a reinforced hip spacer and to select, from the obtained topologies, the one that best improves mechanical properties and prevents stress shielding while minimizing volume. The results indicate that an 8 mm thick titanium reinforcement, optimized to 70% of its original volume, proves to be the most effective choice.