Biomechanical Comparison of Coracoclavicular Fixation Using Metallic Versus All-Suture Anchors

Background:A coracoclavicular (CC) fixation technique using an all-suture anchor with the assistance of fluoroscopy can prevent iatrogenic anterior deltoid detachment from the clavicle; however, soft anchor pullout has been reported as a complication.Purpose:To compare the biomechanical properties of conventional metallic and all-suture anchors for CC suture fixation.Study Design:Controlled laboratory study.Methods:A total of 24 fresh-frozen cadaveric specimens were divided into 2 groups: metal anchor group (group M) and all-suture anchor group (group A). In group M, 5.0-mm metallic suture anchors were used for CC fixation, whereas 2.8-mm all-suture anchors were used in group A. The prepared specimens were mounted on a materials testing machine. After preconditioning at 0 to 20 N for 10 cycles, the specimens were subjected to cyclic loading from 20 to 70 N for 1000 cycles. Finally, all the specimens were loaded to failure. Cyclic elongation, linear stiffness, ultimate load, and failure modes were recorded, and the Mann-Whitney U test was used to compare nonparametric parameters between the 2 groups.Results:All of the specimens completed the cyclic loading test. The elongation after cyclic loading in group M (1.6 +/- 0.6 mm) was significantly smaller compared with that in group A (2.5 +/- 1.2 mm) (P = .02). No between-group differences were found in linear stiffness (42 +/- 17 N/mm in group M and 41 +/- 17 N/mm in group A). The ultimate failure load in group M (263 +/- 66 N) was significantly greater than that in group A (177 +/- 76 N) (P = .02). All specimens failed because of suture anchor pullout.Conclusion:The use of all-suture anchors in CC fixation resulted in significantly greater cyclic displacement and smaller ultimate failure load than that of metallic anchors.Clinical Relevance:Understanding the most biomechanically sound suture anchor may assist in lowering the risk of clinical failure in CC fixation and repair.