Anatomical considerations and biomechanics in distal humeral hemiarthroplasty: are custom-made implants essential?

Distal humerus hemiarthroplasty is a somewhat debated and relatively new therapeutic option for distal humerus fractures, their sequelae, and other humeral degenerative conditions associated with a preserved radioulnar compartment. The anatomical variability of the distal humerus is the main issue that remains to be solved, particularly in view of the limited modularity of the only implant currently available. The clinical relevance of the mismatch between the native joint and the replacement joint has yet to be clearly demonstrated in the long term, though biomechanical studies have highlighted marked ulnar cartilage wear associated with such implants. Clinical studies are needed to understand whether custom-made implants can improve the results yielded by the implant available at present.