Brachialis periosteal avulsion injury: case report with magnetic resonance imaging findings.

Brachialis periosteal avulsion injury is an uncommon injury occurring in young children. The injury may be misinterpreted or overlooked because of misleading or subtle radiological findings. A case of 7-year-old child with post-traumatic elbow pain and subtle findings on elbow radiography is presented. The injury was initially misinterpreted as an avulsion fracture of the medial epicondyle. Following radiological review, a diagnosis of brachialis periosteal avulsion injury was made. The radiographic and magnetic resonance imaging (MRI) findings of this injury are presented to stress the value of comparing the radiographic findings with previous imaging and to increase awareness of this uncommon injury.