Ultimate tensile failure loads of a human dermal allograft rotator cuff augmentation

Purpose: The purpose of this study was to examine the failure mode of supraspinatus tendon repairs with and without human dermal allograft augmentation. Methods: Ten matched pairs of human cadaveric supraspinatus muscles and tendons were detached from their greater tuberosity insertions and then reattached with four simple sutures in 2 suture anchors as a control group. One shoulder from each matched pair was augmented with human dermal allograft secured to the humerus and the supraspinatus tendon using the same sutures and suture anchors. Additional interrupted mattress sutures secured the edges of the dermal allograft to the supraspinatus tendon. Each construct was preloaded at 10 N and then cyclically loaded between 10 N and 100 N for 10 cycles at 20 N/s followed by destructive testing at 33 mm/s. Force and displacement were recorded. Results: The mean failure strengths for the control and augmented constructs were 273 +/- 116 N and 325 +/- 74 N, respectively (P = .047). No significant displacement occurred during the cyclic phase, and no anchors failed. These constructs failed by 2 different mechanisms: tendon-suture interface failure (8/10 non-augmented repairs and 6/10 augmented repairs) and suture breakage (2/10 non-augmented repairs and 4/10 augmented repairs). Conclusions: This examination of the failure characteristics and ultimate failure load of supraspinatus tendon tears augmented with GraftJacket (Wright Medical Technology, Arlington, TN) supported the study hypothesis that a human dermal allograft significantly increases the strength of a repaired tendon. Clinical Relevance: The human dermal allograft can be expected to significantly increase the initial strength of a rotator cuff repair.