Analysis of suture anchor eyelet position on suture failure load

Objective: To compare mechanical performance of 2 orientations of the 5 mm Corkscrew^® suture anchor with #5 Fiberwire^®. Study Design: In vitro biomechanical study. Sample Population: Suture anchor–suture constructs (n=40). Methods: Acute and cyclic tensile loads were applied to suture threaded through eyelets of 40 anchors perpendicular to the long axis of the anchor. Eyelets were positioned so that the suture pull was in line with (anchor rotation angle of 0° [ARA 0]) or 90° (ARA 90) to the eyelet plane. Load at failure, stiffness, and cycles to failure were determined. Results: All constructs failed by suture breakage at the eyelet. Mean load at failure was significantly higher in the ARA 90 group (634±93 N) compared with the ARA 0 group (495±52 N; P=.0015). No significant difference was found between groups for mean number of cycles to failure (270±177 versus 178±109; P=.2166) and stiffness (50±4 versus 48±5 N/mm; P=.3141). Conclusions: The Corkscrew^® 5 mm suture anchor with Fiberwire^® suture fails via suture breakage at the eyelet under higher acute loads if the suture is loaded at an angle of 90° compared with 0° with respect to the plane of the eyelet.