Traumatic valgus instability of the elbow: pathoanatomy and results of direct repair.

BACKGROUND The medial collateral ligament provides valgus stability to the elbow. The purpose of the present study was to describe the pathoanatomy of acute traumatic medial collateral ligament ruptures and to report the rationale and results of direct repair. METHODS Between 1996 and 2006, eleven athletes presented with acute rupture of the medial collateral ligament of the elbow and no history of dislocation. Three patients had received steroid injections for the treatment of medial epicondylitis, but none had a history of medial elbow insufficiency. All patients demonstrated gross valgus instability on clinical examination and medial joint space widening on valgus stress radiographs. Complete avulsion of the medial collateral ligament from its humeral origin was documented with magnetic resonance imaging in all patients. Operative findings uniformly demonstrated avulsion of the flexor-pronator muscles with distal retraction. The underlying medial collateral ligament was avulsed in a sleeve-like fashion from the denuded medial epicondyle. The ligament was directly reattached to its footprint. The avulsed flexor-pronator tendon was repaired to the residual tendon with use of interrupted figure-of-eight nonabsorbable sutures. All patients were followed for a minimum of sixteen months with serial clinical examinations, radiographs, and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. RESULTS Full active range of motion was achieved in ten patients; the remaining patient had a 20 degrees flexion contracture. Three patients had acute ulnar nerve palsies at the time of the injury, and all three recovered complete motor and sensory function by six months after the injury. Nine of the eleven patients returned to competitive college athletics between four and six months. The mean DASH score at the time of the most recent follow-up was 6. CONCLUSIONS Direct repair of an acute traumatic medial collateral ligament avulsion of the elbow reliably restores valgus stability, even in throwing athletes.