A broken ankle is also known as an ankle "fracture." This means that one or more of the bones that make up the ankle joint are broken. (From the American Academy of Orthopaedic Surgeons)
The ligaments of the ankle hold the ankle bones and joint in position. They protect the ankle joint from abnormal movements-especially twisting, turning, and rolling of the foot. When a ligament is forced to stretch beyond its normal range, a sprain occurs. A severe sprain causes actual tearing of the elastic fibers. (From the American Academy of Orthopaedic Surgeons)
The tarsal tunnel refers to the canal formed between the medial malleolus (part of the ankle bone, this is the bump on the inside of the ankle) and the flexor retinaculum (a band of ligaments that stretches across the foot). Inside the tarsal tunnel are the nerves, arteries, and tendons that provide movement and flexibility to the foot.
One of the nerves in the tarsal tunnel is the tibial nerve, which provides sensation to the bottom of the foot. When this nerve is compressed, the resulting condition is called tarsal tunnel syndrome (TTS). Tarsal tunnel syndrome has also been called posterior tibial neuralgia. (From John Hopkins Medicine)