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

Abstract

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