This type of ankle sprain is damage just above the ankle joint, unlike typical ankle sprains which affect the ligaments that attach the ankle bone into the foot. In the case of this type of sprain, there is damage to the ligaments (syndesmotic ligaments) that connects the two leg bones together, the tibia and fibula bones, that together form the top of the ankle joint. The specific ligament is called the anterior inferior tibio-fibula ligament.
The purpose of this ligaments is two fold. One is to keep the fibula bone attached to the lower leg in an effort to form the ankle joint. Additionally, this ligament has some "give" to it so that it expands when the foot is dorsiflexed (lifted upward) in an effort to allow the talus bone of the foot to go through its full range of motion (ankle joint motion). A high ankle sprain is generally a more serious injury then the typical ankle sprain and in most cases takes longer to heal.
HOW DOES THIS TYPE OF SPRAIN OCCUR
The mechanism that creates this injury is the twisting of the foot outward while the lower leg is twisting inward. This causes a torquing of the tibia and fibula bones putting tremendous stress on the syndesmotic ligament to the point where the ligament is damaged or even torn.
Any one may suffer this type of sprain but it is more often than not seen in athletes who have their foot planted in the ground and the impact of someone hitting them like in football or soccer causes the excessive twisting motion. Typically, there will be pain, swelling and eccymosis (black and blue) on the outside of the ankle as well as the front of ankle just above the foot. Rarely do we see pain on the front of the ankle in simple ankle sprains.
DIAGNOSING A HIGH ANKLE SPRAIN
X-rays are taken but it can be difficult to see any change in the position of the tibia and fibula bones.
Stress view x-ray- If a high ankle fracture is suspected a "stress view" may be taken where the mechanism of injury is re-created in an effort to see if there is any widening between the two bones.
MRI- In cases where it is still difficult to make a diagnosis, an MRI may be indicated to determine if there is damage to the syndesmotic ligament.
CT scan (computed tomography) is also helpful as it can demonstrate a widening between the tibia and fibula bones indicating damage to the syndesmotic ligament.
The Squeeze Test is a classic test for this type of sprain, whereby you squeeze the middle of the lower leg from side to side. If there is damage to the syndesmotic ligament then there will be pain.
Klieger's maneuver involves externally rotating the foot relative to the leg. In a high ankle sprain, this too should cause discomfort.
TREATMENT OF HIGH ANKLE SPRAIN
Conservative- Treatment of this type of sprain is along the same lines as treatment for a simple ankle sprain, however, it is not uncommon for this type of sprain to take much longer to heal. The standard treatment of R.I.C.E. (rest, ice, compression and elevation) is in order, but the compression component usually requires a walking boot or cast to better stabilize the tibia and fibula bones.
In more severe cases the patient may have to be non-weightbearing on the affected foot. One of the reasons healing may take longer is due to the chance of misdiagnosis where the diagnosis of lateral or medial ankle sprain is made while in actuality it is a high ankle sprain.
In severe injuries it may take upwards to 8-12 weeks for complete healing and a return to sports. Less time will be required to just return to normal walking activities.
Physical therapy is also very useful for two reasons:1. to facilitate healing and 2. to prevent muscle atrophy.
Surgery- In those cases where pain remains unresolved after a legitimate period of time, surgical intervention is considered where in some cases the ligament is surgically repaired and in other cases a screw may be placed between the tibia and fibula bone to stabilize the stress that it being created during gait.