Arthroscopic Rotator Cuff Repair: A Biomechanical Comparison of Single Row and Suture-Bridge Tendon Repair Constructs

INTRODUCTION: Rotator cuff tears are a very common source of pain and loss of function of the shoulder. As arthroscopic instrumentation and repair techniques have evolved, many studies have demonstrated success in repairing rotator cuff tears using these arthroscopic techniques alone compared with an open repair method. Despite these successful clinical outcomes, both open and arthroscopic rotator cuff repairs have been associated with relatively high rates of failed tendon healing (1). A variety of suture techniques have recently been studied in an effort to find repair constructs that are stronger than conventional single row rotator cuff repairs utilizing simple or mattress type suture configurations. While double row rotator cuff repairs have been shown to increase surface contact area of the repaired cuff to the bone and have biomechanical superiority compared to single row repairs (2), these repairs are technically more challenging. As a result the optimal fixation construct has not been determined. The ideal construct would be technically simple, requiring minimal operative time, while resulting in maximal repair strength, minimal gapping and optimal cross sectional area of tendon to bone contact. The purpose of this study was to compare the gap displacement and strength of a conventional single row rotator cuff repair construct to a new method of rotator cuff fixation that converts a single row repair into a double row type repair using a suture bridge device (PushLock Arthrex Inc, Naples, FL). Our hypothesis was that the gap displacement and strength of the arthroscopic, suture bridge-type, double row cuff repair would be improved relative to the single row repair in cyclic and ramp loading to failure models, respectively.