Non-Circular Shape of the Radial Head

Principal Investigator: Kai-Nan An, Ph.D.
Project Coordinator: Mark Zobitz — zobitz.mark@mayo.edu

The first study considered the effect of radial head orientation on elbow kinematics and radiocapitellar force transmission. Although the native radial head is elliptical, current radial head prosthetic designs have a round radial head component. The purpose of this study was to determine the effect of the shape of the radial head and orientation on kinematics and load transfer in the radiocapitellar joint. The results demonstrated that while the orientation of the elliptical axis did not affect ulnohumeral kinematics, it did significantly influence force transmission across the radiocapitellar joint. This important finding has direct clinical implications, as an increased force on the capitellum may lead to erosion and early arthritic changes to the capitellum. Therefore, restoring the correct orientation of the radiocapitellar articulating surfaces has to be a priority when replacing the radial head with a prosthesis to avoid potential complications.