Human Dermal Allograft Superior Capsule Reconstruction with Graft Length determined at Glenohumeral Abduction Angles of 20 and 40 degrees Decreases Joint Translation and Subacromial Pressure without Compromising Range of Motion: A Cadaveric Biomechanical Study.

Abstract Purpose To compare the biomechanical effects of superior capsule reconstruction graft fixation length determined at 20° and 40° glenohumeral (GH) abduction. . Methods Humeral translation, rotational range of motion (ROM) and subacromial contact pressure were quantified at 0°, 30°, and 60° of GH abduction in the scapular plane in 6 cadaveric shoulders for: intact; massive rotator cuff tear; SCR with a dermal allograft fixed at 20° GH abduction (SCR 20); and SCR fixed at 40° GH abduction (SCR 40). Statistical analysis was conducted using repeated measures ANOVA and paired t-test (P Results Massive cuff tear significantly increased total ROM compared to intact at 0° and 60° abduction. SCR 20 or SCR 40 did not affect ROM. Compared to intact, the massive cuff tear significantly increased superior translation an average of 4.6 ± 0.5 mm at 9/12 positions (P ≤ 0.002). Both SCR 20 and SCR 40 reduced superior translation compared to massive cuff tear (P Conclusion SCR with dermal allograft fixed at 20° or 40° of GH abduction decreases GH translation and subacromial pressure without decreasing range of motion.