WHAT IS A HIGH ANKLE SPRAIN?
The ankle consists of three bones, the tibia, fibula and talus, all held together by thick fibrous ligaments. At the bottom of the leg they form a mortise or hinge joint with the foot. The bottom parts of the tibia and fibula join together and surround the talus in such a way that it is able to hinge forwards and back while providing stability and restricting the side-to-side movements.
Syndesmosis describes the ligaments holding the tibia and fibula together and a high ankle sprain is a tear of these ligaments. A normal ankle sprain is a tear of the ligaments lower in the ankle, and this is why we refer to a syndesmosis tear as a “high” ankle sprain.
HOW DO THEY OCCUR?
These injuries usually occur through twisting of the ankle during sport, however they can also happen with day-to-day activities. The foot is typically pushed back and rotated outwards, putting excess pressure on the ligaments keeping the lower leg bones together. This force can cause the syndesmosis to tear resulting in a gapping of the two bones, which can lead to significant instability of the ankle.
HOW CAN YOU TELL THE DIFFERENCE BETWEEN A NORMAL ANKLE SPRAIN AND A HIGH ONE?
High ankle sprains are much rarer than lower ankle sprains, accounting for only 1-11% of all ankle injuries. It can be very difficult to tell the two injuries apart. To complicate things, a fracture of the ankle will also have similar symptoms. Your physiotherapist will have a set of physical tests they can perform if they suspect a high ankle sprain. Ultimately imaging may be required to confirm the diagnosis.
WHY IS THIS IMPORTANT?
High ankle sprains can take up to two times longer to heal than normal ankle sprains and require more immediate attention. Syndesmosis tears that are left untreated can result in chronic instability and pain, making them vulnerable to further injury in the future.
WHAT IS THE TREATMENT?
Severe and unstable tears may require surgery and most syndesmosis tears will need to be put into a supportive boot for 4-6 weeks. Following this period a rehabilitation program of strengthening, mobilization, balance, control and agility will need to be commenced before your ankle will be at its pre-injury function. Cortisone injections may be recommended in some cases and have been shown to have good results, when accompanied with proper rehabilitation program. Speak to your physiotherapist for more information.