Biomechanical evaluation of augmentation of suture-bridge supraspinatus repair with additional anterior fixation

• Published in: Journal of shoulder and elbow surgery Vol. 22; no. 7; pp. e13 - e18
• Main Authors: Garcia, Ivan A., MD, Jain, Nickul S., MD, McGarry, Michelle H., MS, Tibone, James E., MD, Lee, Thay Q., PhD
• Format: Journal Article
• Language: English
• Published: United States Mosby, Inc 01.07.2013
• Subjects: anterior cord; Biomechanical Phenomena - physiology; biomechanics; Cadaver; external rotation; Humans; Male; Middle Aged; Orthopedics; Range of Motion, Articular - physiology; Reconstructive Surgical Procedures - methods; Rotator Cuff - surgery; Rotator Cuff Injuries; Supraspinatus repair; Suture Anchors; suture bridge; Suture Techniques; Tendon Injuries - surgery; Tensile Strength; Biomechanics; anterior cord; Basic Science; Cadaver Model; external rotation; suture bridge; Supraspinatus repair
• ISSN: 1058-2746; 1532-6500
• DOI: 10.1016/j.jse.2012.10.026

Background Studies have recently focused on evaluating the ability of the supraspinatus repair to withstand rotational loads. Other studies have focused on the importance of minimizing gap formation to avoid decreased healing and failure of repair. The objective of this study was to use a loading model that incorporates external rotation to biomechanically evaluate augmenting a suture-bridge technique for supraspinatus repair with an additional anterior fixation. Methods Eight matched cadaveric shoulder pairs were randomized to 2 different types of repairs after a simulated supraspinatus tear. One group received a standard suture-bridge technique, and the other underwent a suture-bridge repair with an additional anterior fixation consisting of a 4.5-mm suture anchor. A custom apparatus was used to test all specimens, allowing for dynamic external rotation from 0° to 30° during loading. Cyclic loading was performed for 30 cycles from 0 to 90 N, followed by load to failure using a materials-testing machine. Results No differences were found in linear stiffness, yield load, ultimate load, and energy absorbed for load to failure between the 2 groups ( P  > .05). There was a reduction in anterior gapping at ultimate load between the anterior augmentation repair group (6.4 ± 3.1 mm) and the standard suture bridge (9.4 ± 2.8 mm; P  = .037). Conclusion There does not appear to be a biomechanical advantage with the addition of an anterior suture augmentation of a suture bridge for a supraspinatus repair. However, using an anterior augmentation for a suture bridge prevents gap formation at ultimate load in a biomechanical, dynamic external rotation model.