An ankle sprain is the most common injury to the foot and ankle. It accounts for 10-15% of all sports related injuries and is responsible for 7-10% of all emergency room visits each year. It results in pain and a loss of function at home, at work, and on the field.
An ankle sprain is defined as a tearing or stretching of the ligaments around the ankle. Ligaments are the tough tissues that connect the bones around a joint. Because of the anatomy of the bones in our ankle, most ankle sprains (greater than 85%) involve the ligaments on the outside of the ankle. Less commonly, the ligaments on the inside of the ankle or the syndesmotic ligaments (the ligament in between the two upper bones of the ankle, i.e. the tibia and fibula) are involved.
Most commonly, patients describe a twisting injury to their ankle where the ankle “rolled” to the outside. A basketball injury is the most common sports injury to cause an ankle sprain. Patients occasionally feel a tearing sensation or even a pop in the area of the ligament. These injuries can cause a significant amount of bruising and swelling. The more bruising and swelling that develop, the more severe the injury. These higher grade sprains often take longer to heal. Patients with weak muscles on the outside of their legs (peroneal weakness) or high arch feet are prone to having recurrent sprains. Orthotics and therapy can often minimize this risk.
Ankle sprains are sometimes associated with fractures in the foot or ankle. The Ottawa Ankle Rules (OAR) are the commonly used criteria for predicting which patients require xrays after suffering a twisting injury to the ankle. Radiographs are only required for those patients with (1) tenderness at the back edge or tip of the medial or lateral malleolus (the prominent bones on the inside and outside of the ankle respectively); (2) inability to bear weight (4 steps) either immediately after the injury or in the emergency room; or (3) pain at the base of the fifth metatarsal (the prominent bump on the outer border of the foot). MRI is rarely necessary to initially evaluate an ankle sprain but may be useful if the ankle sprain has not resolved with initial treatment within a reasonable amount of time.
Once an ankle sprain has been diagnosed, treatment should begin with rest, icing 20 minutes every 2-3 hours, compression with an ace wrap or brace, and elevation above the level of the heart if possible. These treatments are most important during the first 48-72 hours after the injury. Next, physical therapy is usually very effective in regaining full motion and strength in the ankle and is really extremely important in regaining full, pain free function.
Although some low grade sprains may resolve within 24-48 hours, some high grade sprains may have symptoms that can linger for 2-3 months. Luckily, most sprains resolve fully. When pain does not fully resolve despite appropriate treatment, it may be a sign of injury to another structure. Missed fractures, injuries to the tendons or cartilage, buildup of scar tissue within the joint (i.e. impingement), or continued instability in the ankle can all cause prolonged symptoms after a sprain. Many of these problems can be corrected through therapy, immobilization, bracing, orthotics, injections, or sometimes surgery.
Ankle sprains are very common injuries. Luckily, with appropriate treatment, most people will make a full recovery and be back to their full activities within a few weeks. A strong foot and ankle are the building blocks for the remainder of the legs and the body. A strong ankle should allow you to reserve doing the “Twist and shout” on the dance floor only.