Knotless single-row rotator cuff repair: a comparative biomechanical study of 2 knotless suture anchors.

The purpose of this study was to compare the gap formation during cyclic loading, maximum repair strength, and failure mode of single-row full-thickness supraspinatus repairs performed using 2 knotless suture anchors with differing internal suture-retention mechanisms in a human cadaver model. Nine matched pairs of cadaver shoulders were used. Full-thickness tears were induced by detaching the supraspinatus tendon from the greater tuberosity. Single-row repairs were performed with either type I (Opus Magnum PI; ArthroCare, Austin, Texas) or type II (ReelX STT; Stryker, Mahwah, New Jersey) knotless suture anchors. The repaired tendon was cycled from 10 to 90 N for 500 cycles, followed by load to failure. Gap formation was measured at 5, 100, 200, 300, 400, and 500 cycles with a video digitizing system. Anchor type or location (anterior or posterior) had no effect on gap formation during cyclic loading regardless of position (anterior, P=.385; posterior, P=.389). Maximum load to failure was significantly greater (P=.018) for repairs performed with type II anchors (288±62 N) compared with type I anchors (179±39 N). Primary failure modes were anchor pullout and tendon tearing for type II anchors and suture slippage through the anchor for type I anchors. The internal ratcheting suture-retention mechanism of type II anchors may have helped this anchor outperform the suture-cinching mechanism of type I anchors by supporting significantly higher loads before failure and minimizing suture slippage, potentially leading to stronger repairs clinically.

High tibial osteotomies in the young active patient.

Unicompartmental changes in the knee of a young athlete remains a difficult and controversial problem in orthopaedics. Excessive premature loading of articular cartilage, most often the result of a knee injury, has been shown to result in increased degenerative changes and pain in the younger patient. Instability may also contribute to the degeneration of cartilage and must therefore be considered in the treatment of osteoarthritis in the young adult. High tibial osteotomy has been described as a treatment option for malalignment in the older, less active adult and has shown promising results in a younger, more active population. Osteotomies for instability are more controversial and should be considered in more complex injury patterns.