Most biomechanical studies evaluating arthroscopic rotator cuff repair techniques have shown that double-row and transosseous-equivalent (TOE) repairs are significantly stronger than single-row repairs. Increased strength and contact area are thought to lead to improved healing. However, there is no conclusive evidence showing that improved biomechanical properties lead to an intact repair at the time of follow-up in clinical studies. Though controversial, there is sound clinical evidence that healed rotator cuff tears have improved functional outcomes compared with tears that have not healed after rotator cuff repair. Thus improving healing is the impetus behind development and use of differing repair techniques, yet healing is likely associated with a combination of biomechanical and biological factors.
Double-row repairs have been largely abandoned for the TOE repair because of improved contact area, increased yield load, and reduced operative time. TOE repairs can be performed using various suture configurations but are generally divided between those in which the medial row is tied and all-knotless repairs. Debate on the utility of tying the medial row continues among surgeons performing arthroscopic rotator cuff repairs. Proponents of tying the medial row stress the importance and the improvement of strength of the construct, whereas advocates for the knotless repairs claim no difference in repair strength or clinical out-comes and emphasize the possibility of reduced irritation of the medial knot within the subacromial space. The goal of this systematic review was to examine the published literature to determine whether tying of the medial row of a TOE rotator cuff repair results in improved biomechanical properties of the repair construct. We hypothesized that biomechanical studies would show improved ultimate load, contact pressure, stiffness, and hysteresis with reduced gap formation using arthroscopic TOE rotator cuff repair techniques in which the medial row was tied compared with knotless repairs.