A ankle sprain also recognized as a syndesmotic sprain, is a sprain of the syndesmotic ligaments that attach the tibia and fibula in the lower leg, thereby creating a mortise and tenon joint for the ankle. An ankle sprain refers to tearing of the ligaments of the ankle. The most general ankle sprain occurs on the lateral or outside part of the ankle. This is a very familiar injury which affects several people during a broad range of activities. It can occur in the setting of an ankle fracture. Most usually, however, it occurs in isolation.