Biomechanics of elbow instability: the role of the medial collateral ligament.

The anterior oblique component of the medial collateral ligament of the elbow is the mainstay of joint stability. Fractures of the medial epicondyle must be anatomically reduced, open if necessary. A fibrous union of a minimally displaced fractured medial epicondyle may result in lengthening and functional compromise of the medial collateral ligament. Chronic elbow instability is an unusual lesion. Repair of chronic elbow instability is best performed by restitution of medial collateral ligament function.