A biomechanical comparison of 2 hybrid techniques for elbow ulnar collateral ligament reconstruction

To compare the valgus laxity and fixation strength of 2 hybrid techniques for elbow ulnar collateral ligament reconstructions.

Reflective markers were placed near the ligament attachments of the ulnar collateral ligament on the humerus and ulna of 12 fresh-frozen cadaveric upper extremities for tracking displacement with 4 motion analysis cameras. Valgus laxity testing was performed on the intact, disrupted ligament, and reconstructed elbows by applying a 3.0 Nm moment across the joint at 15° intervals throughout elbow motion from 0° to 120°. Two hybrid techniques for ulnar collateral ligament reconstruction were performed: a proximal docking method and a single-point distal fixation method. Failure testing was performed with the elbow at 90° by applying a cyclic valgus load 12 cm distal to the joint that we increased in 10-N intervals.

Valgus laxity testing revealed no difference in ligament displacements between the 2 techniques over the entire range of elbow motion. Ligament displacement for the proximal docking hybrid technique was significantly higher than the intact at 0° and 15° of elbow flexion. Failure testing revealed no differences in ligament displacements or failure load between the 2 techniques.

Both the proximal docking and the single-point fixation hybrid reconstructions provided sufficient joint stability and strength compared to the intact elbows, with the exception of the proximal docking method at low flexion angles. The reconstructions were not significantly different with respect to valgus laxity or graft fixation displacement at failure.

The proximal docking and single-point fixation hybrids tested here are both viable surgical options with sufficient strength and valgus laxity mechanics, warranting clinical evaluation.