Pediatric ankle injuries: utilizing the Dias-Tachdjian classification

Pediatric ankle injuries require timely diagnosis due to their involvement of the distal tibial physis and subsequent impact on long bone growth. These injuries occur in a predictable pattern based on ankle position, direction of force, and degree of closure of the distal tibial physis. The Dias-Tachdjian classification describes possible ankle injury patterns for the completely open physis, and we present a simplified algorithm for applying this system in routine radiographic interpretation. Similar to the Lauge-Hansen classification in adults, the Dias-Tachdjian system is based on the position of the foot and direction of force at the time of injury with four major patterns: supination-inversion, pronation-eversion external rotation, supination-plantar flexion, and supination-external rotation. In addition, we examine the effect that the closing distal tibial physis has on adolescent fracture patterns (specifically, Tillaux and triplane fractures). Awareness of these injury patterns helps the radiologist to identify nondisplaced fractures and subtle physeal injuries with implications for surgical and/or conservative management.