抄録
The transosseous-equivalent technique (suture-bridge technique) is widely used in rotator cuff repair. However, there have been no biomechanical reports that have assessed the effect of the bridging suture on glenohumeral abduction. The objective of this study was to investigate the effect of bridging suture on glenohumeral abduction. Double-row repair (DR) and double-row repair with the bridging suture (compression double-row repair, CDR) were performed on 32 fresh frozen porcine shoulders. For compression double row repair, a suture limb from each of 2 medial anchors was bridged over the tendon after double row repair, and fixed laterally with 2 sutures of lateral anchor. Each repair was tested for tensile strength at 0° and 40° of simulated glenohumeral abduction to measure the yield load, tensile load, and linear stiffness at a deformation rate of 1 mm/s. At 0° of glenohumeral abduction, the yield and ultimate loads were significantly greater for CDR than for DR (yield load: DR, 44.1 ± 4.2 N; CDR, 137.5 ± 13.6 N and failure load: DR, 69.2 ± 13.7 N; CDR, 153.8 ± 20.5 N). While the yield and ultimate loads after DR at 40 ° of glenohumeral abduction were increased compared to the loads at 0° of glenohumeral abduction, those after CDR at 40° of glenohumeral abduction were significantly decreased compared to the loads at 0° of glenohumeral abduction. There were no significant differences concerning about stiffness between DR and CDR at both 0° and 40°. Bridging sutures increases the tensile strength of repaired tendon at low glenohumeral abduction angle. Increased glenohumeral abduction decreases the effect of the bridging suture on tensile strength after a rotator cuff repair.
