Comparison of internal fi xation methods applied for distal clavicle fractures based on loading tests and stress analysis

Abstract

It is diffi cult to apply rigid fi xation devices to the distal end of an unstable clavicular fracture because of instability, small distal fragment and vicinity to the acromioclavicular joint. In this study, in order to clarify superiority in devices for unstable distal clavicular fracture, we compared three types of internal fi xatives (tension band wiring, hook plate fi xation, and arm plate fi xation) employing two methods. Firstly, fi xatives were applied to loading test using bending stiffness as a rigidity. Secondly, stress analyses were done in two different plates. Bending stiffness was signifi cantly higher in the plate fi xatives than in the tension band wiring. The hook plate was shown higher stress at the hook-bone interface. On the contrary, the arm plate showed no stress concentration on the bone, because the plate did not interfere with the acromioclavicular joint. These results suggested the arm plate could maintain a favorable shoulder function.