Article
Biomechanical Analysis of Thumb Ulnar Collateral Ligament Repair with Suture Tape Augmentation
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Published: | February 6, 2020 |
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Objectives/Interrogation: To assess the kinematics and angular stiffness of the thumb ulnar collateral ligament (UCL) repair with and without suture tape augmentation.
Methods: 8 cadaveric thumbs were tested in a custom hand testing system. Varus/valgus kinematics was measured at -10°, 0°, 15°, and 30° degrees of thumb MCP flexion in the following conditions: (1) intact thumb UCL, (2) complete UCL tear (proper and accessory ligaments), (3) UCL repair, and (4) UCL repair with suture tape augmentation. Angular stiffness was measured after application of sequentially increasing valgus torque in the intact, UCL repair, and UCL repair with suture tape augmentation conditions. UCL repair alone was performed by passing 3-0 FiberWire suture (Arthrex, Naples, FL) in horizontal mattress fashion through the distal UCL from a 3.5 mm DX SwiveLock (Arthrex) at the volar ulnar base of the proximal phalanx. Suture tape augmentation was performed with two tails of 1.3 mm SutureTape (Arthrex) and brought proximally over the repaired ligament and loaded into a 3.5-mm SwiveLock anchor at the proximal origin of the UCL.
Results and Conclusions: Complete UCL tear increased varus/valgus angulation at 0°, 15°, and 30° degrees of thumb MCP flexion (p < 0.02). Thumb UCL repair alone and repair with suture tape augmentation decreased varus/valgus angulation relative to complete UCL tear at all flexion angles (p < 0.002). Total varus/valgus angulation was not significantly different from intact for either the repair alone or the repair with suture tape augmentation at all flexion angles (p > 0.19). Repair with suture tape augmentation had significantly higher valgus angular stiffness compared to repair alone (p =0.040).
Thumb UCL repair with suture tape augmentation is able to restore varus/valgus kinematics after complete UCL tear. In addition, the higher angular stiffness afforded by the suture tape augmentation may allow for earlier rehabilitation after surgery.