Effects of a lateral row anchor position on the suture holding strength of a double-row knotless fixation in rotator cuff repair
Ahmet Emrah Acan1, Onur Hapa2, Levent Horoz2, Aylin Kara3, Hasan Havıtçıoğlu2
1Department of Orthopedics and Traumatology, Muğla Sıtkı Koçman University Training and Research Hospital, Muğla, Turkey
2Department of Orthopedics and Traumatology, Medical Faculty of Dokuz Eylül University, İzmir, Turkey
3Department of Biomechanics, Dokuz Eylül University, İzmir, Turkey
Keywords: Biomechanics; double-row; rotator cuff.
Objectives: This study aims to evaluate the effects of anchor positions on the suture holding strength of a double-row knotless fixation in rotator cuff repair. Materials and methods: Four different double-row fixation techniques were assessed. In group 1, a 15-mm-wide mattress suture was fixed using a knotless lateral row anchor, horizontal to the shaft. In group 2, the medial sutures were fixed with a 5-mm more lateral anchor that was placed at 45° to the long axis of the humeral shaft. In group 3, different from group 2, medial sutures were fixed with a 30-mm mattress suture width. In group 4, the mattress sutures coming from the medial row anchors were fixed to the 10-mm more lateral row, vertical to the long axis of the humeral shaft. The specimens were cyclically loaded from 10 N to 30 N at 0.5 Hz for 50 cycles, and then loaded to failure.
Results: Group 4 had higher cyclic elongation values than group 1 (p=0.021) and group 3 (p=0.006). Group 1 had lower maximum load value than group 3 (p=0.011). Most of the specimens failed with suture ruptures. Unlike the other groups, none of the specimens in group 4 failed via a suture pull through the lateral anchor.
Conclusion: A horizontal lateral row anchor positioned closer to the medial anchor resulted in less cyclic elongation when compared to a more vertically positioned lateral row anchor. The vertical or oblique positioning of the lateral row anchor did not result in any increase in the failure load value; however, the vertical placement prevented a suture pull through the lateral row anchor