Ankle sprains are common injuries and most patients report turning their ankle awkwardly and feeling a pop or a snap. A sprain is a partial or complete tear of one or more of the restraining ligaments in the ankle. Ligament tears are graded on the severity of the ligament damage from 1-3, with a grade 3 sprain regarded as a complete rupture of the ligament. If there is evidence for a complete ligament rupture, an MRI of the ankle to make sure there are no other injuries such as a cartilage is warranted. Most injuries are stable grade I or grade II injuries and can be treated effectively with casting and splinting.
Lateral (outside of the ankle) ligament tears are far more common and these usually involve a ligament in the front/ outside part of the ankle called the anterior talo-fibular ligament (ATFL). Most ATFL injuries will heal after a period of immobilization and physical therapy. Medial ankle sprains are uncommon and involve a ligament known as the deltoid ligament. Patients with medial sprains have pain on the inside portion of the ankle. X-rays will often show a small “fleck” of bone which confirms the ligament has pulled off the bone and taken a small portion of bone with it. If the ankle joint is unstable, these should be repaired. “High” ankle sprains involve a tear of the ligament linking the tibia and fibula (two bones of the lower leg) called the syndesmotic ligament. If this injury is unstable either on injury x-rays or subsequent stress x-rays, surgery to reapproximate the ligament is recommended.
Recovery from higher grade ligament sprains is painfully slow for most patients. Early immobilization of Grade II and Grade III sprains will help control the severity of the soft tissue swelling. Rehabilitation is important to help strengthen the dynamic stabilizers- muscles that help protect from ankle sprains- to compensate for the injured ligament. Reinjury within the first 3-4 months is common and recurrent injuries to the ligament can stretch it out it over time. This can lead to a condition of chronic ankle instability and recurrent sprains. It is therefore imperative that patients treat this injury with an adequate course of immobilization and activity restriction.