Superior Capsule Reconstruction With Fascia Lata Allograft Has Initial Stiffness and Ultimate Load Comparable to the Native Shoulder Superior Capsule: A Cadaveric Biomechanical Study.

Abstract

The purpose of this study was to compare the biomechanical characteristics of a fascia lata superior capsule reconstruction (FL-SCR) to the native superior capsule. The native superior capsule of 8 cadaveric shoulders was tested with cyclic loading from 10 to 50 N for 30 cycles in 20° of glenohumeral abduction followed by load to failure at 60 mm/min. Following native superior capsule testing, FL-SCR was performed, which was tested as described for the native capsule. Paired t test was used for statistical analyses with P < .05 for significance. The stiffness for cycle 1 to 50 N was significantly higher for the native superior capsule compared to the FL-SCR (P = .001). By cycle 30, the stiffness between the two was not statistically different (P = .734). During load to failure, the initial stiffness to 2 mm for the FL-SCR and the native superior capsule was not statistically different (P = .262). The linear stiffness and yield load of the native superior capsule were significantly greater than that of the FL-SCR (94.5 vs 28.0 N/mm, P = .013; 386.9 vs 123.8 N, P = .029). There was no significant difference in ultimate load between the native superior capsule and the FL-SCR (444.9 vs 369.0 N, P = .413). FL-SCR has initial stiffness and ultimate load similar to the native superior capsule. The biomechanical properties of FL allograft make it an appealing option as a graft choice for superior capsule reconstruction.