Acute severe valgus instability without elbow dislocation.

BACKGROUND: The purpose of this study was to investigate the pathoanatomy of acute valgus instability without elbow dislocation and to evaluate clinical outcomes after operative treatment.

METHODS: Seven patients presented with acute severe valgus instability without elbow dislocation or fracture after a single traumatic episode. Five patients had primary repair of the medial collateral ligament (MCL) and flexor-pronator tendon (FPT) with suture anchor. Two patients with highly unstable elbow had primary repair of both the medial and lateral structures. On the basis of magnetic resonance imaging and intraoperative findings, the injury patterns of the ligament, capsule, tendon, and bone structures were evaluated. Clinical outcomes were assessed with the Mayo Elbow Performance Score and the shortened Disabilities of the Arm, Shoulder, and Hand score.

RESULTS: A complete tear of the MCL from its humeral origin and FPT was found in all patients. The anterior capsule was also damaged. A stripping-type complete tear of the lateral collateral ligament complex with significant instability was observed in 2 patients. Bone contusion at the capitellum or radial head was found in 6 patients. The mean Mayo Elbow Performance Score and shortened Disabilities of the Arm, Shoulder, and Hand score at final follow-up were 95.7 and 12.0. All patients returned to previous work levels within 4 months after operation.

CONCLUSION: These results indicate that complete tears of both the MCL and FPT occur with severe valgus instability. Primary repair of medial structures with suture anchor in acute severe valgus instability can restore stability.