Fractures of the lateral margin of the distal tibia. The Tillaux fracture.

Fractures of the lateral margin of the distal tibia are usually avulsion fractures of the anterior or posterior tibial tubercle, caused when the anterior or posterior inferior tibiofibular ligament fails to tear during an injury. Since they are generally the result of external rotation and abduction, they are almost always seen in association with other fractures and ligamentous injuries at the ankle joint. While their presence usually does not change the therapeutic approach, occasionally a large fragment may require a separate fixation screw. Fractures of the posterior tibial tubercle should not be confused with fractures of the posterior articular margin (posterior malleolus), which have a worse prognosis.