Investigation of locking configurations for tendon repair.

Purpose: Locking sutures have proven beneficial to the strength of the repaired tendon. In this study we investigated the effects of 3 locks in the tendon-suture junction and their effect on repair strength.

Methods: Forty-seven fresh pig flexor tendons were transected and repaired using 4-strand repairs with 3 different configurations of locks in each tendon-suture junction: 1 exposed cross-lock, 1 embedded cross-lock, and 1 circle lock. The tendons were subjected to a linear noncyclic load-to-failure test using a tensile testing machine. The initial gap, the 2-mm gap force, and the ultimate strength were measured to compare the biomechanical performance for each repair.

Results: Despite noticeable differences in the configurations of locks the gap formation force and ultimate strength were not significantly different among the 3 tested locking configurations.

Conclusions: An exposed cross-lock, an embedded cross-lock, and a circle lock at tendon-suture junctions had similar locking power. Circle-lock repairs without cross-locking components produce tensile strength similar to cross-locking repairs. The findings of this study suggest that the creation of cross-configurations in locking repairs used conventionally by many surgeons is not essential to repair strength and that circle locking is as efficient as cross-locking in the repair of lacerated flexor tendons.