Do Anatomical Differences of the Volar Rim of the Distal Radius Affect Implant Design? A Three-Dimensional Analysis of Its Anatomy and Need for Personalized Medicine

Abstract

The distal radius, one of the frequent sites of upper extremity fractures, includes unique anatomy referred to as the volar rim. Few studies have addressed its interindividual differences. Additionally, implants for osteosynthesis must match the anatomical structures to prevent soft tissue invasion, but no implants have focused on that so far. In this study, three-dimensional surface models were created from CT images of 101 cases. Analysis of the distal radius, including the volar rim anatomy, was performed to design plates to minimize the discrepancy between the bone anatomy and the implant. The results showed that there were considerable interindividual differences in the morphology of the distal radius, particularly in the degree of palmar protrusion of the volar rim. A moderate correlation between the width of the distal radius and the shape of the volar rim was demonstrated. Considering that variations in plate width are available for treatment of normal distal radius fractures and that the shape of the volar rim changes in correlation with the width of the bone, we infer that simply adding volar rim shape information to the current variations should suffice in preventing complications. We conclude that individualized design according to the shape of the volar rim is unnecessary in fracture surgery.