Irreducible isolated anteromedial radial head dislocation due to ruptured anterior capsule and annular ligament interposition: A case report

Traumatic radial head dislocation without a bone-associated lesion is uncommon, and irreducible cases are rare. We herein present a case of isolated irreducible anteromedial radial head dislocation due to anterior capsule and annular ligament interposition in a 16-year-old female patient. The patient was injured when she was thrown by an opponent during a judo match, and her right elbow was outstretched, combined with forearm pronation. Open reduction was required because of soft tissue interposition into the radiocapitellar joint. The ruptured anterior capsule and annular ligament were repaired using the overlapping suture technique; hence, the radial head was stabilized. At 3.5 years follow-up, the patient had satisfactory elbow function, and redislocation did not occur; however, mild degenerative changes were observed on radiographs. We discussed the injury mechanism using anatomical features in this case and previous literature.