Topology optimised metallic bone plates produced by electron beam melting: a mechanical and biological study

Abstract

Metallic bone plates are commonly used as a medical implant to treat bone fractures. The gold standard materials for these implants are biocompatible 316L stainless steel, cobalt chromium, titanium and its alloys (e.g. CoCrMo and Ti6Al4V). However, the main disadvantage of these implants is the material stiffness mismatch between the implant and bone. This mismatch may negatively affect the biological processes in bone healing. This paper investigates topology optimization to produce plates with reduced equivalent stiffness and the fabrication of optimised plate designs using an electron beam melting (EBM) system. Nonpost-processed EBM plates were assessed against commercially available bone fixation plates in terms of mechanical and biological characteristics. Results show that some redesigned produced plates present mechanical properties similar to the cortical bone and that there is no need to post-process the produced plates in order to establish a good biological bonding with the surrounding tissue.