Improving the Mechanical Properties of Additively Manufactured Micro-Architected Biodegradable Metals

Additively manufactured (AM) micro-architected biodegradable metals offer a unique combination of properties that are ideal for bone regeneration including biocompatibility, a fully interconnected porous structure, and the possibility to fully regenerate bony defects with native tissue upon biodegradation. Currently, the mechanical properties of AM biodegradable porous metals can only match the values of human trabecular bone, hindering their applications for cortical bone regeneration. So far, different approaches have been applied to improve the mechanical properties of AM biodegradable porous metals. Here, we present the state-of-the-art in AM biodegradable porous metals with a focus on the effects of material composition, geometrical design, AM process, and post-AM treatments on their mechanical properties. We also identify a number of challenges encountered in adopting AM biodegradable porous metals for orthopedic applications from the mechanical viewpoint and suggest some promising areas for future research.