The ankle has 3 major bones, the tibia (the large inside “shin” bone), the fibula (the outside narrow bone), and the talus (the foot bone that fits inside the ball-and-socket joint).
Three main ligaments, or straps, hold the ankle bones together:
Anterior Talofibular
Calcaneal Fibular
Posterior Talofibular
When an ankle is sprained, the ligaments above can stretch, partially tear, or completely tear. Without proper treatment, the ligaments will not heal correctly and cause long-term ankle instability, pain, and arthritis. Immediate treatments focus on decreasing swelling.