A biomechanical comparison of 2 ulnar collateral ligament reconstruction techniques.

PURPOSE: To biomechanically compare the Jobe transosseous ulnar collateral ligament (UCL) reconstruction procedure and an interference screw reconstruction (ISR) technique versus the intact elbow UCL.

METHODS: Intact stiffness of 10 matched cadaveric elbow pairs was tested via submaximal valgus loading at 4 flexion angles. From each pair, a metal ISR and a traditional transosseous Jobe reconstruction was performed with the use of matched hamstring tendon grafts. Initial stiffness (graft tension), overall stiffness, strain, and failure strength of reconstructed elbows were then tested.

RESULTS: At each tested flexion angle, Jobe constructs reproduced the initial and overall stiffness of the intact ligament. ISR constructs did not reproduce the overall stiffness of the native ligament at any flexion angle, and they reproduced the initial stiffness only at 30 degrees and 120 degrees of flexion. Jobe constructs were significantly stronger, failing (10 degrees of displacement) at 22.7 Nm after absorbing 1.58 Nm of energy, versus 13.4 Nm and 0.97 Nm for ISR constructs. In all, 40% of bone tunnel reconstructions failed via tunnel fracture, and 70% of interference screw constructs failed via graft slippage.

CONCLUSIONS: The failure strength and initial and overall stiffness of a traditional Jobe bone tunnel UCL reconstruction are superior to those of an ISR, and only traditional Jobe bone tunnel reconstruction reproduces the initial and overall stiffness of an intact UCL.

CLINICAL RELEVANCE: Many UCL reconstruction techniques have been described, and a paucity of biomechanical data supports their use. This study found the Jobe bone tunnel technique to be biomechanically superior to the ISR technique.