Increased Bite Distance From the Edge Lowers Risk of Pullout of Simple Sutures from Acellular Dermal Allograft.

PURPOSE: To investigate whether pullout strength in the acellular dermal allograft matrix (ADM) used for superior capsule reconstruction depends on the distance from the edge of the graft.

METHODS

ADM used for superior capsule reconstruction was obtained and cut into 30 squares. Two sutures were placed through the center of each graft by using a loaded Keith needle and forming a simple stitch. The grafts were divided into 3 groups of 10 grafts with a distance of 5 mm, 10 mm or 15 mm from the closest edge of the graft, respectively. The grafts were then preloaded to 5 N and pulled to failure at a rate of 12 mm/s on an MTS 858 MiniBionix servohydraulic mechanical test frame. The load to failure was recorded as well as the stiffness of each graft.

RESULTS

The mean load to failure was 34.5 N (SD 7.89) for the 5 mm grafts, 31.7 N (SD 5.99) for the 10 mm grafts, and 66.2 N (SD 18.4) for the 15 mm grafts. There was a significant difference (< 0.0001) between the large grafts (15 mm) and the 2 smaller grafts (10 mm, 5 mm). There was no significant difference in stiffness between the groups of graft (P 0.40).

CONCLUSION

Placing the suture at least 15 mm from the edge of the graft increases the graft's ultimate yield strength to suture pullout.

CLINICAL RELEVANCE: The depths of the suture in ADM could improve pullout strength for constructs of superior capsular reconstructions.