 A bimalleolar fracture is a fracture of the ankle that involves the lateral malleolus and the medial malleolus.Studies have shown that bimalleolar fractures are more common in women, people over 60 years of age, and patients with existing comorbidities.A trimalleolar fracture is a fracture of the ankle that involves the lateral malleolus, the medial malleolus, and the distal posterior aspect of the tibia, which can be termed the posterior malleolus.