Imaging Case of the Week 481 Answer

The ankle x-rays show a Salter Harris III fracture of the distal tibial epiphysis also called ”Tillaux fracture”.

On the frontal view, there is a vertical lucent fracture line in the distal tibial epiphysis. The lateral ankle view shows irregularity of the anterior aspect of the distal tibial epiphysis with significant soft tissue swelling.

The patient underwent operative fixation of the fracture.

Tillaux fracture is a fracture of the anterolateral distal tibial epiphysis with avulsion of the fragment due to pull from the anterior tibiofibular ligament. Mechanism involved is external rotation of the ankle. Seen in adolescents during closure of the growth plate which starts medially and extends laterally. This means anterolateral part of the distal tibial growth plate is the last one to fuse and represents the weakest point.