Chronic Ankle Sprains (Lateral Ankle Instability): Overview

Chronic Ankle Sprains (Lateral Ankle Instability): Overview

A lateral ankle sprain is an injury to the lateral side or outside of the ankle. It is the most common type of ankle sprain, with about 85% of all sprains being lateral and estimations of over 2,000,000 occurring every year in the United States. Patients of all ages and all activity levels can sprain their ankle. It can happen to young athletes playing sports, someone injuring it at work, or simply from taking a wrong step while walking on the sidewalk. Sometimes, people will refer to it as rolling their ankle. When the foot turns in and causes the injury, the ligaments on the outside of the ankle are stretched and can tear through if the injury is severe enough.

Let us review the anatomy of the ankle and see what happens on the inside. Looking at this right ankle and foot from the outside, just beneath the skin, there are tendons that attach the muscles of the lower leg to the bones in the foot. These tendons help stabilize the ankle while doing any type of movement like running or jumping and especially walking on uneven ground. The ligaments that connect bone to bone are the last line of defense if the tendons cannot keep the ankle stable during activity. The bones are the fibula, tibia, talus, and calcaneus. The ligament most commonly injured in lateral ankle sprains is the anterior talofibular ligament, or ATFL for short. It is the first ligament that is stretched when the foot starts to roll in. The ATFL connects the talus to the fibula. Other ligaments can be involved depending on how severe the injury is.

That is usually the next question a patient has: how bad is my ankle sprain? There is a simple, well-known grading system that health care providers use when it comes to lateral ankle sprains. Grade 1 is considered a mild sprain. The ligament is stretched but still intact. The patient typically can still put some weight on their foot, but they will have some discomfort and likely a bit of a limp. Grade 2 injuries mean a partial tear of the ligament. It is harder to put weight on it, and most people will want to use crutches to avoid the pain of walking on it. Grade 3 ankle sprains have a completely torn ligament. Crutches are needed, and patients do not want to put any weight on their foot at all.

After spraining an ankle, patients usually have immediate pain in the front of their ankle, on the outside, or both. The less weight they want to put on it, the more severe the injury probably is. Obvious swelling on the outside of the ankle and foot is expected. Sometimes, bruising will show up around the heel and even extend down the foot into the pinky toe. The health care provider will examine the ankle, checking to see where the pain is. They will check the ligaments and tendons that might be involved. Even though sprains usually just involve soft tissue, x-rays can be taken of the ankle to make sure there are no fractures in the bones. Here, someone had a bad ankle sprain which actually did break the tip of their fibula, the outer ankle bone. This may change how their ankle sprain is treated.

At this point, a diagnosis of an ankle sprain can usually be made with confidence, including how bad it is grade 1, 2, or 3. However, the picture of an ankle sprain may be different in someone who gets it over and over. Once somebody has one ankle sprain, chances are they are going to have another. Someone can develop chronic instability after one ankle sprain that did not heal right or after multiple ankle sprains. Their ankle might just give out suddenly, and it probably feels a bit unstable all the time. After their third or fourth ankle sprain, the health care provider is more interested in how loose their ankle is and will move it in certain directions to check it.

Regarding injury prevention, doing various band exercises can help strengthen the ankle, but research has shown that different kinds of balance exercises actually provide more benefit. Also, braces usually do a better job of preventing ankle sprains for someone who has already had several instead of someone who has never had one. At the end of the day, if a patient has had only one ankle sprain or several of them, getting the right treatment based on an accurate diagnosis can allow patients to get back to the activities they need to do as well as the ones they want to do.