Causes and failure modes of recurrent defects after rotator cuff repair

Background. Recurrent defects of the rotator cuff remain a significant complication after surgical repair. Objectives. The current review focuses on the etiology of structural redefects with regard to the underlying pathophysiology, structural changes of the musculotendinous unit, patient demographics and implant-specific failure modes. Materials and methods. Systematic review of the online databases PubMed, EMBASE and Cochrane Library. Results. The goal of preserving the structural integrity of the rotator cuff after reconstruction has led to a number of improvements of all aspects of rotator cuff surgery and tendon healing. Nevertheless, rotator cuff redefect rates remain high. Structural failure of the reconstructed rotator cuff is multifactorial, but specific risk factors that adversely affect the osteofibroblastic integration at the tendonbone unit can be identified. Conclusion. Pathomorphological changes of the musculotendinous unit (fatty infiltration >= grade II according to Goutallier, advanced atrophy, or retraction), patient-specific factors (age >65 years, bone quality, smoking, AHA <7 mm), choice of the implant or reconstruction technique, and the postoperative rehabilitation (application of NSAIR, patient compliance) are decisive for the outcome of the tendon reconstruction.