A syndesmotic ankle sprain is an injury to one or more of the ligaments comprising the distal tibiofibular syndesmosis; it is often referred to as a "high ankle sprain." Syndesmotic ankle injury is much less common than the typical ankle sprain, but is associated more often with significant morbidity and the need for surgical treatment. . An external rotation force applied to a dorsiflexed ankle is the most common mechanism. This can happen when the leg is rotated forcefully against a planted foot or toe.Pain from a syndesmotic injury is usually focused along the anterolateral ankle but may be more diffuse and severe if medial ligaments are disrupted. Athletes with severe injuries are usually unable to continue sport activity due to severe pain with any weight bearing. Common findings in patients with a high ankle sprain include antalgic gait or inability to bear weight, lateral and possibly anterior ankle edema, as well as tenderness over the anterior inferior tibiofibular ligament (AITFL) One of the most difficult aspects of evaluating a high ankle sprain is distinguishing between grade 1 (partial tear of AITFL; treated conservatively) and grade 2 (complete tear of AITFL; generally treated surgically) injuries. Referral to a knowledgeable orthopedic surgeon is indicated for grade 2 and grade 3 syndesmosis injuries and any grade 1 injury associated with a fracture.