An in-vitro study of rotator cuff tear and repair kinematics using single- and double-row suture anchor fixation

PURPOSE: Double-row suture anchor fixation of the rotator cuff was developed to reduce repair failure rates. The purpose of this study was to determine the effects of simulated rotator cuff tears and subsequent repairs using single- and double-row suture anchor fixation on three-dimensional shoulder kinematics. It was hypothesized that both single- and double-row repairs would be effective in restoring active intact kinematics of the shoulder. MATERIALS AND METHODS: Sixteen fresh-frozen cadaveric shoulder specimens (eight matched pairs) were tested using a custom loading apparatus designed to simulate unconstrained motion of the shoulder. In each specimen, the rotator cuff was sectioned to create a medium-sized (2 cm) tear. Within each pair, one specimen was randomized to a single-row suture anchor repair, while the contralateral side underwent a double-row suture anchor repair. Joint kinematics were recorded for intact, torn, and repaired scenarios using an electromagnetic tracking device. RESULTS: Active kinematics confirmed that a medium-sized rotator cuff tear affected glenohumeral kinematics when compared to the intact state. Single- and double-row suture anchor repairs restored the kinematics of the intact specimen. CONCLUSIONS: This study illustrates the effects of medium-sized rotator cuff tears and their repairs on active glenohumeral kinematics. No significant difference (P ≥ 0.10) was found between the kinematics of single- and double-row techniques in medium-sized rotator cuff repairs. CLINICAL RELEVANCE: Determining the relative effects of single- and double-row suture anchor repairs of the rotator cuff will allow physicians to be better equipped to treat patients with rotator cuff disease.