A Comparison of Cyclic Valgus Loading on Reconstructed Ulnar Collateral Ligament of the Elbow

A COMPARISON OF CYCLIC VALGUS LOADING ON RECONSTRUCTED ULNAR COLLATERAL LIGAMENT OF THE ELBOW. Roshan P. Shah, Derek P. Lindsey, Gannon W. Sungar, Timothy R. McAdams. Section of Sports Medicine, Department of Orthopaedic Surgery, Stanford University, Stanford CA. (Sponsored by Michael J. Medvecky, Department of Orthopaedic Surgery, Yale University School of Medicine.) This study compares the biomechanics of early cyclic valgus loading of the ulnar collateral ligament (UCL) of the elbow repaired by either the Jobe technique or the docking technique. Better understanding of the biomechanical properties of each reconstruction may help surgeons choose the optimal surgical technique, particularly in planning earlier rehabilitation programs. Sixteen fresh frozen cadaver limbs (eight pairs) were randomized to either the Jobe cohort or the docking cohort. First intact UCLs were tested, followed by the repaired constructions. A Bionix MTS apparatus applied a constant valgus load to the elbows at 70 flexion, and valgus displacement was measured and then used to calculate valgus angle displacement. The docking group had significantly less valgus angle displacement than the Jobe group at cycles 100 and 1,000 (p = 0.0189 and 0.0076, respectively). Four of the eight specimens in the Jobe group failed at the tendon-suture interface before reaching 1,000 cycles, at cycles 7, 24, 250, and 362. None of the docking specimens failed before reaching 1,000 cycles. In this cadaveric study, the docking technique resulted in less angulation of the elbow in response to cyclic valgus loading as compared to the Jobe technique. The better response to valgus loading of the docking reconstruction may translate into a better response to early rehabilitation. Further study is needed to determine if this difference translates into improved clinical outcomes.