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:
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.