Endoscopic Gluteus Medius Repair Replicates Open, Knotless Repair With Similar Cyclic Loading Properties: A Cadaveric Study

PURPOSE: To compare the repair strength, gap formation, and mode of failure between endoscopic and open double-row gluteus medius repairs in a cadaveric model. METHODS: Six pairs of fresh-frozen human cadavers were used in this study. Gluteus medius tears were created in an open fashion and then repaired with either open or endoscopic techniques. Specimens were manually preloaded to 5 N, then cycled between 20-50 N for 150 cycles s. Then, a ramp to/s. Specimens were then returned to 10 N and ramped to failure at 1 mm/s. Gap formation and strengths of the construct were compared for the 2 techniques. RESULTS: Biomechanical testing resulted in no significant differences in ultimate load (P = .86) or gap formation (P > .10) between groups. Ninety-two percent of specimens failed near the muscle origin on the ilium. CONCLUSIONS: This study shows that both open and endoscopic gluteus medius repairs are stronger than the muscle–bone interface in a cadaveric model and loaded biomechanically in tension between the ilium origin and femoral insertion. Further, endoscopic technique is able to replicate open, knotless gluteus medius repair technique in terms of gap formation in physiologic (i.e., subfailure) cyclic loading. CLINICAL RELEVANCE: Gluteus medius tendinopathy is an increasingly common recognized etiology of lateral hip pain. When tears occur, debate exists over whether open or endoscopic repair procedures are optimal. Double-row endoscopic gluteus medius repair with knotless suture anchors may be an alternative to open repair.