Posterolateral rotatory instability of the elbow in association with lateral epicondylitis. A report of three cases.

ateral stability of the elbow depends on the integrity of the lateral collateral ligament and secondary softtissue restraints. Posterolateral rotatory subluxation of the elbow has been recognized in association with elbow trauma, surgery for epicondylitis, and congenital cubitus varus deformity. While abnormal signal changes on magnetic resonance imaging have been shown to include the lateral collateral ligament in patients with tennis elbow, we are aware of no reports of elbow instability detected in patients in whom epicondylitis had been managed nonoperatively. We describe the cases of three middle-aged women who presented with atraumatic lateral epicondylitis and subsequently had clinical findings consistent with posterolateral rotatory instability of the elbow. Two of the patients had a visible synovial fistula and magnetic resonance imaging studies indicative of insufficiency of the lateral collateral ligament. All three patients eventually underwent an examination of the elbow under anesthesia, which confirmed the posterolateral rotatory subluxation. All were treated with débridement and reconstruction of the common extensor tendon origin and the lateral collateral ligament. The potential role of corticosteroid injections in the pathogenesis of combined lateral epicondylitis and rotatory instability of the elbow is discussed. Each patient was informed that data concerning her case would be submitted for publication.