The tibia (shin bone) and the fibula are the bones of the lower leg. Pilon fractures are injuries that occur at the lower end of the tibia and involve the weightbearing surface of the ankle joint. The fibula also may be broken. These injuries were first described more than 100 years ago and remain one of the most challenging problems for orthopaedic surgeons to treat. Common causes of pilon fractures are falls from a height and car accidents.

A talus fracture is a broken ankle bone. The talus is the bone in the back of the foot that connects the leg and the foot. It joins with the two leg bones (tibia and fibula) to form the ankle joint and allows for upward and downward motion of the ankle.

The talus (ankle bone) sits within the ankle mortise or hinge, which is made up of the two leg bones, the tibia and fibula. There are three joints:

• the ankle, which allows the up-and-down motion of the foot with the leg
• the subtalar joint, which allows for side-to-side movement
• the talonavicular joint, which has a complicated biomechanical function that controls flexibility of the foot and the arch of the foot.

The talus has no muscular attachments and is mostly covered with cartilage, which makes injuries difficult to heal.