Voluntary reducible recurrent anterior dislocation of radial head in juvenile baseball player. A case report and review of the literatures.

12 years-old baseball player came to our hospital with snapping sensation of his right elbow during throwing a ball. He started to feel this feeling when he was in early childhood, however, he had never had any significant trauma to the elbow since then. The radial head was anteriorly dislocated with pop sensation when the patient extended his elbow in forearm supination. Radiographic images showed no obvious deformities of elbow joint and malalignment of forearm. Corrective ulnar osteotomy with annular ligament repair using anconeus fascia flap was performed. After four weeks immobilization, range of motion exercise was started. Subsequently, there was no recurrence of radial head dislocation, and he could play baseball for 5 years without any symptoms until graduating high school. Abnormal kinetics of radial head during repetitive forearm rotation caused by slight undetectable forearm malalignment might induce the insufficiency of the annular ligament and eventually bring on the anterior radial head dislocation. Corrective ulnar osteotomy with annular ligament repair provided a good long-term result in this case.