BIOMECHANICS OF A LESS INVASIVE PROCEDURE FOR RECONSTRUCTION OF THE ULNAR COLLATERAL LIGAMENT OF THE ELBOW

A reconstruction of the anterior bundle of the ulnar collateral ligame nt of the elbow using bone anchors was compared regarding strain and v algus load strength with the intact ulnar collateral ligament and the reconstructed ulnar collateral ligament using bone tunnels. In both no rmal and reconstructed elbows, the anterior band and posterior band we re tight during only a portion of the range of motion. Toward extensio n, the mean peak strain in the anterior band was tight for the normal and bone anchor groups, but lax in the bone tunnel group. Toward exten sion, the mean peak strain in the posterior band was lax in all elbows . Toward flexion, the strain in the anterior band was lax in the norma l and bone anchor groups, but tight in the bone tunnel group. The mean of the peak strains for the posterior band toward flexion was tight f or all elbows. Mean valgus load strength of normal elbows was 22.7 +/- 9.0 N.m. The bone tunnel and bone anchor mean strengths were 76.3% an d 63.5%, respectively, of normal elbow strength. We concluded that the bone anchor reproduced the normal anatomy and mechanical function of the ulnar collateral ligament more closely than the bone tunnel, and t hat both reconstruction methods were significantly weaker than the nor mal ulnar collateral ligament. However, we found no significant differ ence in reconstruction strength between bone anchor and bone tunnel.