Abstract
Introduction: We have devised a new technique of lesser tuberosity osteotomy with double row fixation of the subscapularis using suture anchors.
Aim: To evaluate the biomechanical properties of this novel technique against two established methods of subscapularis repair including tendon to tendon and transosseous repairs.
Method: Matched pairs of human cadaveric shoulders were allocated into 3 groups. Group 1 consisted of the double row technique with incision of the subscapularis along the bicipital groove with a lesser tuberosity osteotomy. A double loaded suture anchor was placed along the medial border of the osteotomy site and sutures were passed through subscapularis medial to the bone island in a horizontal mattress manner. A second anchor was inserted along the lateral border of the osteotomy site and the two sutures were tied onto the subscapularis holding sutures. In group 2, the subscapularis was divided 1cm medial to the bicipital groove and repaired with tendon to tendon suturing. In group 3, the subscapularis was repaired to the cut humeral neck through transosseous tunnels. The cyclic elongation, load to failure, displacement and mode of failure were analysed.
Results: All specimens in Group 1 and 40% of Group 2 and 3 passed the cyclic loading test. The ultimate tensile strength in Group 1 was found to be 2.8 times that of Group 2 and 2.4 times that of Group 3 (p< 0.05). Simple suturing failed by suture cutting out of soft tissue and tranosseous repair failed by a combination of the suture cutting out through bone and soft tissue.
Conclusion: This novel technique is simple to perform and biomechanically stronger than established methods of repair. A stronger fixation may allow early mobilization without the risk of tendon rupture and is much less likely to loosen with gap formation and subsequent fibrous tissue interposition. Additional advantages include bone to bone healing without violation of the subscapularis tendon.
Correspondence should be addressed to The Secretary, British Elbow and Shoulder Society, Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PE
