Sprained ankles occur frequently in all sports. Sprains may occur in any ligament in the ankle, but most sprains involve the lateral ligament complex--that is, the group of ligaments on the outside of the ankle. These ligaments are named for their location and the bones to which they are attached: a) the anterior talofibular ligament (front), b) the posterior talofibular ligament (back), and c) the calcaneofibular ligament (middle). (See illustration.) Sprains of the lateral ligament complex are produced by forced inversion and flexion movements of the ankle.

Ankle sprains are graded as 1, 2, or 3, depending on the extent of the injury. Grade 1 sprains are very mild, involving stretching of the ligaments or, perhaps, small partial tears, usually of the anterior talofibular ligament. Treatment consists of rest, the use of ice, compressive bandages, and elevation of the ankle, and early active use with the ankle bandaged, taped, or in a specialized splint.

Grade 2 sprains are complete tears of the anterior talofibular ligament and the calcaneofibular ligament but involve only mild stress to the posterior talofibular ligament. In addition to the measures mentioned above, treatment consists of providing support with tape, an inflatable splint, or a cast for 3 to 6 weeks, followed by rehabilitation of the ankle and lower leg muscles to improve ankle stability.

Grade 3 sprains involve complete rupture of all the ligaments of the lateral complex. Treatment of these serious sprains of the lateral ligaments is somewhat controversial. Because the injury results in gross instability, surgical repair may be necessary for some patients. Whatever treatment the physician chooses, complete restoration of muscle strength through physical therapy and rehabilitation is essential to avoid another sprain in the same ankle.

Residual weakness is common after any ankle sprain and can cause swelling and discomfort Ankle stability can be improved over the longterm by heelcord stretching and other exercises to strengthen leg and ankle muscles.

Eduardo Robles, M.D.