Initial Fixation Strength of Transosseous-Equivalent Suture Bridge Rotator Cuff Repair Is Comparable With Transosseous Repair

Abstract

Background: The outcome of rotator cuff repair correlates with tendon healing. Early studies of arthroscopic rotator cuff repair demonstrate lower healing rates than traditional open techniques. Transosseous-equivalent repair techniques (suture bridge) were developed to improve the initial fixation strength. Purpose: To compare the initial in vitro tensile fixation strength of a transosseous-equivalent suture bridge (TOE-SB) rotator cuff repair construct to a traditional transosseous (TO) suture construct. Study Design: Controlled laboratory study. Methods: Identical simulated rotator cuff tears were created on 8 matched pairs of humeri. Each matched pair underwent repair with 4 sutures using either the TOE-SB or TO technique. Initial fixation strength was tested in a custom testing jig. Each shoulder underwent 1000 cycles each of low and then high load testing. Gap displacement was measured at anterior and posterior sites of the repair with digital video tracking of paired reflective markers and recorded at predetermined cycle intervals. Results: There were no statistically significant differences in gap formation at the repair sites under low or high load conditions between TOE-SB and TO techniques. The mean maximal gap formation of the repairs during low load testing in the TOE-SB and TO constructs was 0.93 ± 0.88 mm and 0.55 ± 0.22 mm, respectively (P = .505). The mean maximal gap formation during high load testing in the TOE-SB and TO constructs was 2.04 ± 1.10 mm and 2.28 ± 1.62 mm, respectively (P = .517). The most significant increase in gap distance occurred at the transition from low load to high load in both constructs. Most of the incremental displacement occurred within the first 100 cycles for both high and low load testing (P < .001). Conclusion: The arthroscopic TOE-SB technique is comparable in initial fixation strength to the traditional TO simple suture repair technique. Clinical Relevance: Arthroscopic techniques can achieve initial fixation strength comparable with traditional TO techniques performed without suture anchors.