Transbrachialis Buttonholing of the Radial Head as a Cause for Irreducible Radiocapitellar Dislocation: A Case Report

Background: Isolated dislocation of the radial head is an uncommon injury among pediatric patients. Although closed reduction may be successful, some patients require open reduction with or without soft-tissue repair or reconstruction. If the radiocapitellar joint is not properly reduced, the long-term complications of pain, stiffness, neuropathy, and dysplasia can result from chronic radial head dislocation. Methods: While performing a cartwheel, a 13-year-old gymnast sustained a radiocapitellar dislocation that was unable to be reduced by closed means and failed 2 attempts at open reduction. Ultimately, the radial head was determined to have translated anterior to the brachialis muscle during the dislocation and subsequently buttonholed through the muscle as the elbow was flexed and rotated. It remained suspended by the brachialis tendon, preventing anatomic reduction. Once the radial head was delivered from this tendinous sling, anatomic restoration of the radiocapitellar joint was obtained. Results: Ultimately, the patient was able to return to full, unrestricted activity. At 9 months following surgery, she denied pain, and the elbow was stable upon examination. Elbow range of motion was 5 to 130 degrees with 80 and 90 degrees of pronation and supination respectively. Conclusions: This represents the first reported case of suspension transbrachialis buttonholing of the radial head in the brachialis tendon as a cause of initially irreducible radiocapitellar dislocation. When evaluating patients with persistent anterior subluxation or dislocation of the radial head, this etiology should be considered.