A high ankle sprain injures the large ligament above the ankle that joins together the two bones of the lower leg. These two bones, the tibia (shin bone) and fibula, run from the knee down to the ankle. They are joined together by this ligament called the "syndesmosis" or "sydesmotic ligament." Patients who sustain a high ankle sprain injure this syndesmotic ligament.
What are the symptoms of a high ankle sprain? A high ankle sprain causes pain similar to other ankle sprains, but patients often complain of pain when the ankle is turned to the outsid,e or when the calf is squeezed. This later finding, the so-called "squeeze test," is the classic test for syndesmotic injuries, but it is not very reliable for diagnosis.
How is a high ankle sprain diagnosed? When a syndesmotic injury is suspected, we will obtain x-ray studies of the ankle, and possible a special view called a "stress view". The ankle can look normal on routine x-rays even with a syndesmotic injury, but when stressed, there is abnormal motion between the bones (the tibia and fibula) where the syndesmotic ligament attaches.
What is the treatment for a high ankle sprain?
Syndesmotic injuries tend not to heal as well as lateral ankle sprains. This is why we are especially concerned about "high ankle sprains." In our office, will first determine if the injury is stable or unstable. If the injury is stable, then the high ankle sprain can be treated in a cast, usually for a period of 6 weeks.
If the injury is unstable, then a "syndesmotic screw" or a specialÂ type of suture called a "tight rope" can be placed between the tibia and fibula to hold the bones in proper position while the syndesmotic ligament heals.
Patients will have the screw in place for about 2-3 months while the syndesmotic ligament heals. Patients should understand that the screw can break. The reason for this is that there is normally some motion between these bones when people walk. Therefore, some doctors prefer a second operation to remove the sydensmotic screw before allowing the patient to walk, or to use the tight rope which doesn't have to be removed.