Pilon fractures affect the bottom of the shinbone (tibia) at the ankle joint. In most cases, both bones in the lower leg, the tibia and fibula, are broken near the ankle. Pilon is a French word for pestle, an instrument used for crushing or pounding. In many pilon fractures, the bones of the ankle joint are crushed due to the high-energy impact causing the injury. Pilon fractures may be considered high-energy ankle fractures.