In vitro and finite element analysis of a novel rotator cuff fixation technique

The purpose of this investigation was to assess the biomechanic strength and stress dispersion at the repair site of surface-holding repair techniques for rotator cuff repair compared to the double-row technique. Eighteen bovine infraspinatus tendons were repaired using 3 different repair techniques: double-row repair, surface-holding repair with transosseous sutures, and surface-holding repair with knotless anchors. Biomechanical testing and two-dimensional finite element analysis were performed. The surface-holding repair with transosseous sutures provided 87.9% more stiffness than the double-row repair. The number of tendon-suture site failures of the surface-holding repair with transosseous sutures was smaller than the other 2 techniques. The finite element analysis showed that the surface-holding repair model had a more dispersing stress pattern compared to a double-row repair model. It suggests that these repair techniques can prevent high stress concentration compared to the double-row repair.