Arthroscopic Repair of Triangular Fibrocartilage Tears: A Biomechanical Comparison of a Knotless Suture Anchor and the Traditional Outside-In Repairs

Purpose To compare the biomechanical strength of a knotless suture anchor repair and the traditional outside-in repair of peripheral triangular fibrocartilage complex (TFCC) tears in a cadaveric model. Methods We dissected the distal ulna and TFCC from 6 matched cadaveric wrist pairs and made iatrogenic complete peripheral TFCC tears in each wrist. In 6 wrists, the TFCC tears were repaired using the standard outside-in technique using 2 2-0 polydioxane sutures placed in a vertical mattress fashion. In the other 6 wrists, we repaired the TFCC tears using mini-pushlock suture anchors to the fovea. The strength of the repairs was then determined using a materials testing machine with the load placed across the repair site. We loaded the repairs until a gap of 2 mm formed across the repair site, and then subsequently loaded them to failure. Thus, for each repair we obtained the load at 2-mm gap formation, load to failure, and mode of failure. Results At the 2-mm gap formation, the suture anchor repairs were statistically stronger than the outside-in repairs. For load to failure, the suture anchor repairs were also statistically stronger than the outside-in repairs. Failure in both techniques occurred most commonly as suture pull-out from the soft tissues. Conclusions The all-arthroscopic suture anchor TFCC repair was biomechanically stronger than an outside-in repair.(Copyright (C) 2013 by the American Society for Surgery of the Hand. All rights reserved.