Biomechanical evaluation of a rotator cuff defect model augmented with a bioresorbable scaffold in goats

A bioresorbable patch used for augmentation of rotator cuff repair was evaluated to determine if it would increase strength of cuff repairs associated with tendon defects and also show histologic incorporation over time. Forty goats underwent rotator cuff repairs of the infraspinatus tendon bilaterally. Tendons were detached and a defect was created prior to repair. One side was repaired and augmented with a 4 cm2 polylactic acid patch in each animal. On the other side, the same size defect was repaired in the same manner but without the patch to serve as a control. Animals were sacrificed at 3, 6, 12, and 24 weeks. Ultimate load to failure and histology were reported. No significant difference in load to failure was found between groups. A cellular fibrous tissue occupied the patch at 6 weeks, which over time matured into a dense, homogeneous fibrous tissue with alignment of collagen between the scaffold bundles.