Arthroscopic suture anchor capsulorrhaphy versus labral-based suture capsulorrhaphy in a cadaveric model.

Purpose: The purpose of this study was to establish whether suture anchor capsulorrhaphy (SAC) is biomechanically superior to suture capsulorrhaphy (SC) in the management of recurrent anterior shoulder instability without a labral avulsion.

Methods: Twelve matched pairs of shoulders were randomized to either SC or SAC. Specimens were mounted in 60° of abduction and 90° of external rotation. Testing was conducted on an MTS servohydraulic load testing device (MTS, Eden Prairie, MN). A compressive load of 22 N was applied, followed by a 2-N anterior and posterior force to establish a 0 point. Translation with 10-N anterior and posterior loads was recorded for baseline laxity measurement. Arthroscopic capsulorrhaphy was performed with either 3 solitary sutures or 3 suture anchors. Specimens were remounted and returned to the 0 point. Translation was measured with 10-N anterior and posterior loads to determine reduction in translation. Specimens were then loaded to failure to the 0 point at a rate of 0.1 mm/s.

Results: Load to failure was significantly greater (P = .02) in the SC group (13.6 ± 1.0 N) versus the SAC group (20.5 ± 2.8 N). No differences were found between SC (2.7 ± 0.7 mm) and SAC (2.3 ± 0.6 mm) when we compared reduction of anterior translation with a 10-N load. The percent reduction of anterior displacement with a 10-N load was similar for the SC (49.9%) and SAC (49.6%) groups. The dominant mode of failure in the study was suture pull-through of the capsular tissue.

Conclusions: Our study indicates that labral-based SC and SAC similarly reduce anterior glenohumeral translation at low loading conditions. Load-to-failure studies indicate that SAC exhibits significantly greater resistance to translation at higher loading conditions. Our study suggests that the use of a suture anchor when one is performing a capsulorrhaphy may provide biomechanical advantage at high loading conditions.

Clinical Relevance: Our study suggests that when one is performing capsulorrhaphy, the use of a suture anchor may provide biomechanical advantages at high loading conditions.