High ankle sprain (syndesmosis)

A high ankle sprain is an injury to the ligaments that connect the bones of the lower leg above the ankle (tibia and fibula). This strong connection forms the top of the hinge of the ankle joint. This is also known as the ‘syndesmosis’ and is made up of a number of ligaments at the base of your lower leg, as well as a connective tissue that joins the bones from the top of the ankle all the way up to your knee. High ankle sprains are more serious injuries than more standard lateral ankle sprains (rolled ankle), and generally require more assessment and management. Injuries to the syndesmosis are often associated with lateral ankle injury; however, they usually lead to more pain, swelling and activity limitations. In severe cases, they may also be accompanied by a fracture.

--What causes high ankle sprain?

High ankle sprains occur slightly differently to normal ankle sprains (ankle rolling outwards). They often happen when the foot is trapped underneath someone—in a tackle, for example—and the foot is twisted and rotated outwards. Another common mechanism is rolling directly forward over the ankle (not just sideways). It often helps your physiotherapist to describe exactly how the injury occurred (rolled over it while walking vs caught under someone else), as this may help them diagnose what areas are injured.

--How do I know if I have high ankle sprain?

High ankle sprains are usually more severe than normal ankle injuries, and are often accompanied by swelling and pain, not only on the outside of the ankle joint but also over the front at the end of your tibia and fibula (lower leg bones). Often walking may be more painful at the bottom of your leg and top of the ankle, as weight-bearing causes the syndesmosis to separate slightly because of the ligament injury.

Your physiotherapist will be able to diagnose a high ankle sprain, and will ask you about how the injury happened. Often this condition is missed as people presume the injury was just a normal ankle sprain, and if you delay seeing your physiotherapist, it will be important to discuss how the sprain has changed since injury. They will look at your ability to walk, stand on one foot and do simple exercises such as a calf raise. It will also be important to do specific tests for the high ankle ligaments. If you are unable to walk because of the injury, or if your physiotherapist suspects it is a more serious injury, you may be referred for an X-ray or MRI for further assessment.

--How can physiotherapy help with high ankle sprain?

Physiotherapy will be essential for effective rehabilitation from a high ankle sprain. The first step is to identify the severity of the injury. Minor injuries can be managed conservatively; however, more severe cases, where there is significant laxity or ‘gapping’ of the syndesmosis at the top of the ankle, will require surgery to stabilise this area.

Early management of high ankle sprains may involve a period of non-weight bearing on crutches and in a CAM boot to allow the injury a chance to begin early healing. Your physiotherapist will guide you as to how long you will need to do this for, based on the severity of the injury. Once this early phase is over, you will be able to begin walking, and it will be important to begin strengthening exercises to regain the strength and function of your leg and ankle. As your function improves, you will be guided back into running and then whatever desired activity you are returning to. It will also be important to develop the confidence to use your ankle again for pushing off, jumping and stopping as required.

--How effective is physiotherapy for high ankle sprain?

Currently, no high-quality trials investigating physiotherapy treatment for high ankle sprains exist. Most research into the area is limited to expert opinions and recommendations, as well as surgical case series. Clinical opinions largely agree that a period of non-weight bearing is recommended early for less severe injuries, and that the length of time immobilised depends on the severity of the injury. Surgery appears to be effective for more complex injuries; however, no studies exist comparing surgical to conservative treatment.

--What can I do at home?

In the early phase, immediately after a high ankle sprain, your physiotherapist will advise you on how long to spend non-weight bearing. It will be important to adhere to these guidelines to allow proper healing of the injury. In the early stages, ice may help with pain, and using a compression bandage and elevation may help reduce swelling. During this phase, you will be able to do strengthening exercises for your unaffected leg. This may be helpful to prevent loss of strength, as around 20 per cent of the strength gains will be carried over from the uninjured side to the affected side. This may help in a quicker return to activity or sport. Once you are able to begin exercising and strengthening, it will be important to complete the program outlined by your physiotherapist.

--How long until I feel better?

High ankle sprains take significantly longer to get better than normal ankle sprains. When managed conservatively, it will take at least six weeks, and more complex cases may take closer to three months to return to full activity without symptoms. High ankle sprains result in higher rates of long-term complications than normal ankle sprains, and it will be important to address all areas before returning to sport and activity.

Clinical content contributed by APA physiotherapist Michael Girdwood
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