The pilon fracture is a distal tibial metaphyseal fracture, usually with intra-articular comminution. The injury usually involves a fracture of the medial malleolus, the anterior margin of the tibia, and a transverse fracture of the posterior tibial surface. 75% of pilon fractures have associated fibula fractures.
Pilon fractures are named after the French word "pilon," meaning pestle, an object used for crushing or pounding. The French radiologist Destot first used the term "hammer fracture" to describe how the talus drives itself into the tibial plafond (the joint surface of the distal tibia) and causes a pilon fracture.