Isolated Distal Ulnar Salter-Harris IV Fracture in an Adolescent Male With Distal Radioulnar Joint Injury: A Case Report and Review of the Literature.

Distal ulnar physeal fractures are uncommon in pediatric patients, and isolated Salter-Harris IV (SHIV) injuries of the distal ulna are particularly rare. These injuries may raise concern for distal radioulnar joint (DRUJ) incongruity, limited forearm rotation, and future growth disturbance. Management strategies vary depending on fracture displacement, reducibility, and joint stability. A 14-year-old male patient presented with left wrist pain three days after a bicycle accident. Examination demonstrated tenderness over the distal ulna and restricted wrist and forearm motion, including pronation and supination. Radiographs showed a SHIV fracture of the distal ulna. On presentation, the patient underwent closed reduction and sugar-tong splint immobilization in the emergency department. After closed reduction, forearm rotation remained limited, and concern persisted for DRUJ incongruity/mechanical block, prompting operative fixation the following day. Open reduction and Kirschner wire fixation were performed through a dorsal approach with fluoroscopic confirmation of fracture alignment and DRUJ congruity. Follow-up radiographs at approximately two weeks and six weeks demonstrated maintained alignment and hardware position. The patient did not return for additional follow-up, limiting long-term assessment for physeal arrest, DRUJ symptoms, and functional outcome. This case describes a rare distal ulnar SHIV fracture in an adolescent and highlights the importance of individualized management based on fracture characteristics and DRUJ assessment. In this patient, surgery was selected because of concern for rotational block/instability rather than as a general recommendation for all distal ulnar physeal injuries. Longitudinal follow-up remains important in these injuries because growth-related complications may not be clinically apparent early after treatment.