Design optimisation improves the performance of custom distal humeral hemiarthroplasty implants

Elevated cartilage contact stresses following distal humeral hemiarthroplasty (DHH) can lead to cartilage erosion. This study uses design optimisation techniques to modify the shape of custom anatomic implant shapes to minimise peak contact stresses. Implants based on the distal humerus shape plus a subject-specific offset distance ranging from 0.75 to 1.42 mm were optimal, whereas, the population-optimised offset was 0.97 mm. Comparing population versus subject-specific optimised designs, no differences were observed in terms of resulting contact areas or stresses. Furthermore, a trade-off which exists when optimising to minimise peak stresses at the ulna versus the radius was quantified.