Malleolar fractures are commonly encountered in emergency medicine. They typically result from twisting injuries.

• Two-thirds are isolated to the lateral malleolus (distal fibula)
• One quarter are bimalleolar (also involving the medial malleolus)
• 7% are trimalleolar (lateral and medial malleolus plus posterior distal tibia)
• 2% are open fractures

The primary issue when assessing these injuries is ankle stability.  Fractures are less stable when:

• fibula fractures are at or proximal to the tibia-fibula syndesmosis
• medial and lateral ankle injury is present.