Snapping elbow with congenital radial head dislocation: case report.

An 11-year-old boy with congenital radial head dislocation experienced painful snapping of his left elbow upon movement. He had no previous history of trauma. A plain radiograph of his left elbow showed anterior dislocation of the radial head and flexion deformity of the hypoplastic radial neck. Arthroscopy showed that the snapping of the elbow occurred between the annular ligament and the dislocated radial head during elbow flexion and extension. After the annular ligament was released, the snapping immediately disappeared. Five years after the surgery, the patient has no pain or snapping upon elbow movement.