Chronic ankle instability: What treatments work?

Strength and coordination training can help in the treatment of chronic ankle instability. People who start rehabilitation exercises as early as two to three weeks after the operation become active again sooner than people who do not start until six weeks after the operation.

A sprained ankle can turn into permanent (chronic) ankle instability. Ankle instability is considered chronic if six months after the first sprain the ankle joint still gives way too easily or if the ankle was sprained again. An unstable ankle joint can easily twist again. About 10 to 20% of people with ankle sprains develop chronic ankle instability. You can read more about ankle sprains in our fact sheet.

The ankle joint can become unstable if the ligaments were overstretched or torn and have grown back together too loosely (mechanical instability). In addition, the interaction of the bones of the joint with the surrounding ligaments and muscles may be disrupted. This phenomenon is also known as impaired proprioception. Proprioception plays a decisive role in our sense of our own body position and movement and can work at an unconscious level. Using the information coming from the inside of our body it is responsible for the coordination of ligaments and muscles, movements, and balance. So if the ankle feels permanently unstable, this might not only be caused by overstretched ligaments, but also by an impaired proprioception or muscle coordination.

Treatment options for chronic ankle instability

There are different treatment options for chronic ankle instability. At first, functional treatment, involving physiotherapy and possibly wearing an ankle brace, is tried. One common method is called neuromuscular training. It aims at improving the strength, stability and coordination of the ankle. If the joint remains unstable despite training because the ligaments are too loose, they may be shortened in surgery. One surgical option is to restore the function of the ligaments by shortening and tightening them. Another option is to take a tendon out of the calf and use it as an external ligament for the ankle. The tissue of tendons and ligaments is similar. Whereas ligaments connect bones to each other, tendons join muscles to bones.

Even if surgery can resolve the problem in the interior of the ankle, long-term instability has probably also led to problems in muscle coordination. This is why rehabilitative exercises after the operation are an important part of treatment. Wearing a brace during this time also helps. A brace not only provides external support to the joint – the pressure is also meant to stimulate the sense of good muscle coordination.

The research

The best way to find out what treatment leads to the fastest recovery in ankle sprains is to test different treatments in randomized controlled trials. In this kind of trials, volunteers are assigned randomly to different groups. Participants in the treatment groups all receive the same treatment, the one that is to be tested. A control group receives a different treatment. This means that the participants do not choose the treatment themselves, but that the kind of treatment they receive is decided by chance. Because of this procedure it is then clear that different outcomes really are an effect of a particular treatment, and there are no differences in the group compositions that might influence the outcomes. For example, if the participants chose the treatment themselves it might happen that very athletic people preferred a certain therapy. Differences in the healing process might then be caused by the physical fitness of the participants rather than the treatment itself.

In order to find out what the best treatment for chronic ankle instability is, researchers at the Cochrane Collaboration looked for good-quality trials on the different therapies. The Cochrane Collaboration is an international network of researchers whose members analyze results of trials. They found ten trials on chronic ankle instability involving a total of just under 400 participants. Two thirds of the participants were men. The participants were all adults that had ankle instability for more than six months.

Early rehabilitation has slight advantages

The trials show that neuromuscular training can improve the stability and the mobility of the ankle. These trials lasted only a few weeks, meaning that they cannot tell us anything about long-term effects this treatment has on the ankle.

Other trials compared two different types of follow-up treatment after surgery. One of these treatments was immobilization: The participants wore an ankle brace for six weeks to stabilize and rest their foot.

Another treatment was early rehabilitation: In this treatment participants also wore an ankle brace after the operation, but only rested the foot for two to three weeks, and then started with an exercise program to improve mobility. This program involved bending and stretching the foot in different directions. After five weeks coordination and strength training was added to these exercises.

These trials showed that, in the short-term, rehabilitative treatment soon after surgery had advantages over longer periods of foot immobilization. People who participated in rehabilitation programs were able to return to work earlier (about one to two weeks) and do sports earlier (about three weeks) than those who had kept their foot immobile. After about two years, however, neither group showed an advantage over the other: the stability and mobility of the affected ankle was the same in both groups.

It remains unclear whether an operation is better than rehabilitation on its own

There were no trials comparing a surgical approach directly with physiotherapy or other rehabilitation programs. For this reason, we cannot say at what stage surgery is a good option or how much of a benefit it might have compared to treatment without surgery.

It is also not clear how the surgical procedures compare with one another. There are only few small trials on this, and they are not very conclusive. One trial examined a surgical procedure called “Chrisman Snook”, which takes tendons from the foot or the calf to strengthen the ligaments. But there were more complications, including nerve damage. This might mean that other surgical procedures are better, but more research is needed to be certain.

No matter what treatment was used: chronic ankle instability improved in most people. It remains unclear whether surgery leads to faster healing. If instability persists and it is caused by loose ligaments, surgery can be an option.

To read more about the different treatment options for ankle sprains and how to prevent new sprains click here.

Author: Institute for Quality and Efficiency in Health Care (IQWiG)

Next planned update: January 2015. You can find out more about how our health information is updated here.

© IQWiG (Institute for Quality and Efficiency in Health Care)