Transitional Fracture Patterns of the Pediatric Distal Radius

Distal radius fractures involving the physis are among the most common upper extremity injuries in children and adolescents. Unlike transitional fractures of the distal tibia, known as Tillaux and triplane fractures, transitional fractures of the distal radius have not been well characterized. This study aims to evaluate Salter-Harris III and IV fractures of the distal radius in the pediatric transitional age population to determine if a characteristic fracture pattern exists analogous to the distal tibia. We hypothesized that pediatric transitional fractures of the distal radius would follow a pattern that would ultimately dictate treatment and predict outcomes.

A retrospective chart review of pediatric patients with transitional fractures of the distal radius at a single institution was performed. Salter-Harris III and IV fractures of the distal radius with CT imaging were included. Two independent reviewers determined the metaphyseal fracture plane and the major intra-articular epiphyseal fracture fragments. Descriptive statistical analysis was performed.

Thirty patients who met inclusion criteria made the study cohort. There were 5 Salter-Harris III fractures and 25 Salter-Harris IV fractures. Mean age at the time of injury was 15±1.5 years. The metaphyseal fracture demonstrated a coronal fracture plane in all cases, and 20% had a sagittal plane component. The major epiphyseal fracture fragments were identified as dorsal ulnar corner in 70%, radial column in 43%, volar rim in 30%, and dorsal wall in 17%. Patients were treated with open reduction and internal fixation (N=12, 40%), closed reduction and percutaneous pinning (N=4, 13%), or cast immobilization (N=14, 47%). Most patients (N=24, 80%) did not demonstrate a growth disturbance after treatment. Angular deformity, however, was significantly higher in patients with a primary dorsal ulnar corner epiphyseal fragment (N=4, 19% vs. N=0%, P =0.03).

Transitional fractures of the distal radius occurred on average at age 15. The injuries demonstrated a consistent pattern, with a coronal fracture plane in the metaphysis and a dorsal ulnar corner fragment in most epiphyses. The dorsal physis may be the strongest portion of the distal radius at the time of injury, though mechanism of injury may impact patterns as well.

Level III.