Use of a Novel Hybrid Suture Technique for Arthroscopic Rotator Cuff Repair: A Biomechanical Study

Abstract

Currently, arthroscopic rotator cuff (RC) repair is performed using a single row or double row suture-anchor configuration. Both of these techniques have demonstrated advantages in biomechanical pull-out strength (double row), and postoperative clinical outcomes and decreased operative time (single row). However, these separate techniques lack the advantages of the other and retear of RC repair is common in both cases with the primary mode of failure because of the suture cutting through the tendon. The aim of this study was to design 2 novel hybrid suture techniques that incorporated both double and single row concepts and to determine the biomechanical pull-to-failure strength compared with a single row inverted mattress suture. We hypothesized that the novel techniques would have superior biomechanical properties at the tendon-suture interface, as is seen in double row techniques, and that it would be fast with minimal hardware, as seen in a single row repair. The study consisted of 3 groups of 12 ex vivo sheep shoulders. Group 1 used an inverted mattress stitch with tension-band configuration using 2 knotless suture anchors (1 suture per anchor) and acted as the control. Group 2 (Double time) and group 3 (Reverse double time) were different versions of a hybrid combining concepts from a transosseus equivalent and a single row inverted mattress suture. Groups 2 and 3 used the same number of sutures and anchors as group 1. Failure occurred at the tendon-suture interface in all specimens in all groups (100%). Biomechanical analysis showed group 2 had a mean ultimate failure load (252±38 N; P<0.02), stiffness (20±3 N/mm; P<0.01), and total energy to failure (3.6±0.5 N m; P<0.03) that was almost twice that of group 1 (135±20 N; 9±1 N/mm; 2±0.3 N m). Similarly, group 3 had a mean stiffness (14±2 N/mm; P<0.02) and total energy to failure (3.7±0.6 N m; P<0.03) that was significantly higher than group 1. There were no significant differences between all groups in mean peak energy to failure (P>0.05). The use of 2 novel hybrid suture techniques improved the biomechanical pull-to-failure strength of RC repairs. Further in vivo research in humans is necessary for determining clinical efficacy; however, these initial findings suggest there is much potential for an optimized hybrid technique that incorporates the advantages of current single-row and double-row repairs so that repairs have strong pull-out strength, are fast and easy to perform, and have the best clinical outcomes. Basic science study.