Mechanical Augmentation With Absorbable Alginate Sheet Enhances Healing of the Rotator Cuff

For anatomical restoration of a repaired rotator cuff, mechanical augmentation of the repaired structure is essential. Using histological and biomechanical evaluation in a rat model, the authors sought to determine the efficacy of an absorbable alginate sheet at the supraspinatus tendon-to-bone repair site for healing of the rotator cuff tear. Forty adult (12 weeks old) male Sprague-Dawley wild-type rats were used in this study. The animals were randomly separated into 2 groups: group 1, conventional supraspinatus repair with acute repair; or group 2, supraspinatus repair with absorbable alginate sheet. Biomechanical and histological analyses were performed at 6 and 12 weeks after index rotator cuff surgery. Compared with group 1, group 2 exhibited a significantly greater mean ultimate failure load (group 1, 23.70 +/- 3.87 N; group 2, 61.44 +/- 43.67 N; P=.023) and mean ultimate stress (group 1, 2.83 +/- 0.50 MPa; group 2, 7.36 +/- 2.87 MPa; P=.020). However, 6-week outcomes were not significantly different. On histological scoring, compared with group 1, group 2 exhibited a significantly greater mean 6-week score (group 1, 4.10 +/- 1.72 points; group 2, 7.80 +/- 1.47 points; P<.001) and mean 12-week score (group 1, 3.50 +/- 1.00 points; group 2, 5.25 +/- 2.62 points; P=.020). Mechanical augmentation with absorbable alginate may improve tendon healing after surgical repair of the rotator cuff.