Background: Repair of a torn rotator cuff should have sufficient initial strength of the fixation to permit appropriate rehabilitation.
Hypothesis: Augmentation with a woven polylactic acid scaffold strengthens repairs of the rotator cuff.
Study design: Controlled laboratory study.
Methods: In the suture-anchor model, 10 pairs of sheep infraspinatus tendons were detached and repaired to suture anchors. In half of the matched specimens, the repair was reinforced with a woven poly-lactic acid scaffold repaired with the tendon to bone. In the bone-bridge model, sutures were passed through a trough and over a bone bridge distal to the greater tuberosity; half were reinforced by the scaffold. The repairs were tested to failure with a hydraulic testing machine.
Results: The mean ultimate strength of suture-anchor repairs augmented with the scaffold (167.3 +/- 53.9 N) was significantly greater than that of nonaugmented fixation (133.2 +/- 38.2 N). Failure occurred when the tendon pulled through the sutures; the scaffold remained intact. Scaffold reinforcement of the bone bridge significantly increased the ultimate strength from 374.6 +/- 117.6 N to 480.9 +/- 89.2 N, and the scaffold remained intact in 8 of 10 specimens.
Conclusions: The scaffold significantly increased the initial strength of rotator cuff repair by approximately 25%.