Superior Capsule Reconstruction With Subacromial Allograft Spacer: Biomechanical Cadaveric Study of Subacromial Contact Pressure and Superior Humeral Head Translation

To investigate the biomechanical effects of superior capsule reconstruction with subacromial allograft spacer on superior humeral head translation and subacromial contact pressure. Eight cadaveric shoulder specimens were tested in 4 conditions: (1) intact rotator cuff, (2) supraspinatus tear and superior capsule excision, (3) superior capsule reconstruction with human dermal allograft, and (4) superior capsule reconstruction with subacromial resurfacing using human dermal allograft. In each condition, specimens were tested at 0, 30, 60, and 90° of shoulder abduction in balanced and unbalanced loaded states for subacromial contact pressure and superior humeral head translation. Statistical comparisons were made using a repeated-measures analysis of variance test, followed by a Tukey post hoc test for pairwise comparisons. A P value