A Pilot Biomechanical Study to Evaluate the Efficiency of New Implant to Fix Acromioclavicular Joint

The incidence of acromioclavicular joint (ACJ) injuries is high in daily activities and sports. Various surgical procedures have been used to restore the performance of the shoulder complex in ACJ injuries. This study was aimed to introduce a new implant designed to fix ACJ and to evaluate its efficiency on the basis of biomechanical modeling and finite element analysis approaches. Computerized tomography scan images of 12 normal shoulders were selected to create a 3d model of shoulder joints. The dimensions of the implant were obtained from the models of shoulder joints and then were evaluated on 5 fresh cadavers. The stress developed in the implant and shoulder articular surfaces were evaluated by finite element analysis on the basis of the models obtained from computerized tomography scan images. The designed implant can be used to fix ACJ for both right and left sides. The stress developed in the implant varied between 1.88 and 2.1 MPa. The newly designed implant can be used for most of the subjects to fix ACJ for both rights and left sides. The stress developed in the implant in the abduction of the shoulder joint was significantly less than the yield strength of the material used for the implant. Therefore, it can be used without failure for most of the daily activities.