This in-vitro study evaluated the influence of ligament tensioning and the effectiveness of lateral collateral ligament (LCL) repair using transosseous sutures on the initial kinematics and stability of the elbow.

Six fresh upper-extremities were mounted in a motion simulator with tracking system, which enabled both passive and simulated active elbow flexion. The intact elbow was tested then the LCL was sectioned from its humeral origin and repaired with a transosseous suture technique. Locking sutures were placed in the LCL and passed through a humeral bone tunnel entering at the centre of curvature of the capitellum with exit holes in the lateral epicondyle. An actuator pulled on the sutures to achieve 20, 40 and 60 N of LCL repair tension and the sutures were then secured. The dependent variable of this study was the motion pathways of the ulna relative to the humerus. The data were analyzed using a two-way, repeated-measures ANOVA with relevant post-hoc paired t-tests.

With the arm oriented in the horizontal position under varus gravity loading, the repairs tracked in greater valgus than the intact LCL regardless of the repair tension. The larger the initial repair tension, the more the elbows tracked in valgus. Initial tension of 60 N was statistically different than the intact LCL with the forearm in pronation (p=0.04). Both the 40 and 60 N initial tensions were statistically different than the intact LCL with the forearm in supination (p< 0.01).

Repair of the LCL using transosseous sutures effectively restores the varus stability of the elbow. The initial tension of LCL repairs affects the kinematics of the elbow, with a tendency to over-tighten the ligament and pull the elbow into valgus. These data suggest that acute repair of the LCL should be performed using a transosseous suture technique, and that a tension of 20N or perhaps less is sufficient to restore stability.