Tillaux fractures are intraarticular (Salter-Harris III) avulsion fractures of the anterolateral epiphysis.
These fractures are classified as 43t-E/5.1.
These fractures occur in adolescents approaching skeletal maturity, when the tibial physis is closed on the medial side. The anterolateral component of the distal tibial physis remains open and is prone to injury.
This injury is a result of external rotation of the foot. The inferior tibiofibular ligament avulses the tibial epiphyseal fragment anteriorly and laterally.
AP and lateral x-ray of a Tillaux fracture
AP, mortise, and lateral x-rays of a Tillaux fracture
CT image of the same case