Pediatric Distal Forearm and Wrist Injury: An Imaging Review

Abstract

Injuries to the pediatric distal forearm and wrist have myriad manifestations. Growth plate injuries can occur in the skeletally immature child. An unfused growth plate is less robust than ligamentous complexes and therefore is more easily injured. The Salter-Harris fracture classification system is used to grade physeal injuries based on their imaging appearance. This grading has prognostic significance: higher grades imply an increased likelihood of eventual growth disturbance. A disrupted distal radioulnar joint characterizes Galeazzi-type injuries at all ages; however, before skeletal maturity is attained, a disrupted radioulnar joint can manifest as a distal ulnar physeal separation with associated epiphysiolysis of the distal ulna, termed a Galeazzi-equivalent fracture. Bone contusions can be diagnosed using fluid-sensitive fat-suppressed magnetic resonance imaging, and their detection can alter the prognosis. The unique cartilaginous cushion of the developing bony carpus imparts resilience to fracture and dislocation until carpal maturity is reached. Chronic compressive forces to the wrist in a skeletally immature gymnast can result in a distinct pattern of bone and soft-tissue injury referred to as gymnast wrist. If the distal radial physis fuses prematurely, ulnar growth will outpace radial growth, leading to positive ulnar variance and consequent chronic wrist pain from ulnar impaction.