Trimalleolar fracture

An oblique fracture of the lateral malleolus (arrow on AP and lateral x-rays) proximal to the joint, in addition to fractures of the medial malleolus (arrowhead on AP view) and posterior malleolus (dashed arrow on lateral view), are seen here. Note how the posterior malleolar fracture and the displacement of the fibular fracture can only be seen on the lateral view. The diastasis between the tibia and fibula reflects a syndesmotic injury. The highly unstable nature of trimalleolar fractures is reflected in the loss of joint congruence and the abnormal increased width between the medial malleolus and the talus.