A biomechanical analysis of capsular plication versus anchor repair of the shoulder: can the labrum be used as a suture anchor?

Abstract

To determine the biomechanical strength properties of suture capsulolabral plication to an intact labrum versus glenoid bone anchor fixation. Fourteen paired fresh frozen shoulders with intact glenoid labrum and mean age of 43.3 +/- 11.1 were randomized to capsular plication in the anteroinferior and posteroinferior quadrants using either two suture-anchor fixation versus suture fixation to an intact labrum. The construct was then preconditioned at 10 N for 10 cycles (1 Hz), and then loaded to failure at 3 mm per minute. There was no statistical difference in ultimate load to failure between the suture anchor (304.3 +/- 92.8 N) and the intact labrum (285.6 +/- 66.7 N) groups. The suture anchor group demonstrated significantly less mean displacement (2.15 +/- 1.1 mm) than suture plication (3.43 +/- 1.38 mm; P = .007) at failure. There were no statistical differences of labrum strength and stiffness between the anteroinferior and posteroinferior quadrants. An intact labrum provides similar fixation strength to a glenoid anchor; however, the labrum displacement was higher with plication alone. There were no strength differences between the anteroinferior and posteroinferior labrum. However, displacement of up to 1.5 mm may be expected without the use of glenoid anchors. The intact posteroinferior or anteroinferior labrum provides similar fixation strength to a glenoid anchor; however, the labrum displacement is higher versus plication alone.