A New Technique for Reconstruction of the Ulnar Collateral Ligament of the Thumb

Abstract

Background Several previous studies have described reconstructive methods for the treatment of an injury to the ulnar collateral ligament of the thumb. However, there are few biomechanical studies to date to analyze the strength of the surgical reconstruction. Purpose To evaluate 2 reconstruction techniques with use of a cadaveric model (1) reconstruction with the use of a free tendon graft placed in a figure-of-8 fashion through drill holes in the metacarpal and proximal phalanx of the thumb, and (2) reconstruction with the use of the Bio-Tenodesis Screw System. Study Design Controlled laboratory study. Methods Eight matched pairs of cadaveric specimens underwent removal of the proper and accessory ulnar collateral ligaments. One of the 2 reconstruction methods was performed, and specimens were mounted on a materials-testing machine. The specimens were subjected to valgus stress to failure at 30° of flexion. Failure was defined as valgus laxity of 30° at the metacarpophalangeal joint. Results The peak load to failure was 23.5 ± 11.4 N for the figure-of-8 reconstruction and 24.3 ± 12.3 N for the reconstruction using the Bio-Tenodesis Screw System. Comparing the 2 groups, there was no statistically significant difference in peak loads to failure (P = .88). Conclusion There was no statistically significant difference between the peak loads to failure of the 2 reconstructions. Clinical Relevance The Bio-Tenodesis Screw System may provide another viable option for surgical reconstruction of the ulnar collateral ligament of the thumb.