Comparison of a Novel Anatomic Technique and the Docking Technique for Medial Ulnar Collateral Ligament Reconstruction

Background: Current reconstruction techniques do not re-create the distal ulnar collateral ligament (UCL) insertion. Reconstructing the distal extension of the anterior band ulnar footprint may increase elbow stability and resistance against valgus stress after UCL reconstruction (UCLR).

Purpose/hypothesis: The purpose was to test a new technique for UCLR, a modification of the docking technique, aimed at re-creating the distal ulnar footprint anatomy of the anterior band. We hypothesize that this novel "anatomic" technique will provide greater resistance to valgus stress after UCLR when compared with the docking technique.

Study design: Descriptive laboratory study.

Methods: Eighteen unpaired cadaveric arms were dissected to capsuloligamentous elbow structures and potted. With use of a servohydraulic load frame, 5 Nċm of valgus stress was placed on the UCL-intact elbows at 30°, 60°, 90°, and 120° of flexion. UCLR was performed on each elbow, randomized to either the docking technique or the anatomic technique. After UCLR, the elbow was again tested at 30°, 60°, 90°, and 120° of flexion. Ulnohumeral joint gapping was calculated using a 3-dimensional motion capture system applied to markers attached to the ulna and humerus. Differences in gapping among the intact state and docking and anatomic techniques were compared using a 2-way analysis of variance with significance set to P < .05.

Results: There was no significant difference in gapping between the anatomic and docking technique groups regardless of elbow flexion angle. All reconstructed groups showed increased gapping relative to intact, but all increases were below the clinically relevant level of 1 mm.

Conclusion: Ulnohumeral joint gapping and resistance to valgus stress were similar between the anatomic technique and the docking technique for UCLR.

Clinical relevance: This study provides evidence that the anatomic technique is a viable alternative UCLR method as compared with the docking technique in a cadaveric model.