High Ankle Sprains

In the lower leg, the two bones, the tibia and fibula, meet twice: once near the knee and once just above the ankle joint. The distal tibiofibular joint (the one just above the ankle joint) has ligaments that connect the two bones in the front and back of the joint. These ligaments blend together with the connective tissue that runs between the two bones throughout the lower leg (called the syndesmosis or the syndesmotic ligament). Injuries to the distal tibiofibular ligaments are referred to as “high” ankle sprains due to their location in relationship to the rest of the ankle joint. Syndesmosis sprains often occur with high ankle sprains either at the same time that the high ankle sprain occurs or shortly afterward due to the syndesmosis having to absorb higher forces than usual after the tibiofibular ligaments are sprained.

Causes

High ankle sprains are caused when the foot is excessively and/or forcibly externally rotated on the leg, when the foot is forced into full dorsiflexion (the motion of pulling the toes up toward the rest of the body), or a combination of these two movements. One of the most common causes of high ankle sprains is someone or something falling on the back of the lower leg.

In external rotation and in dorsiflexion, the talus moves upward into the ankle joint, putting pressure on the tibia and especially the fibula. When these motions happen at high speeds or beyond the range of motion normally allowed by the joint, this upward motion of the talus ends up displacing the fibula laterally. In order for this lateral movement of the fibula to occur, the tibiofibular ligaments and the syndesmosis must structurally fail (become sprained) OR one of the involved bones has to fracture (fibula) or dislocate (talus).

Once the tibiofibular ligaments are damaged, continued weightbearing or foot rotation can contribute to damage to the syndesmosis. This occurs because the syndesmosis is not designed to resist spreading forces between the tibia and fibula as well as the tibiofibular ligaments are. The syndesmosis essentially rips apart, going up from the ankle, every time a spreading force occurs, like a seam being pulled apart.

Signs and Symptoms

The two main symptoms associated with high ankle sprains are severe pain and loss of function in the ankle. Pain from high ankle sprains is typically:

• Located on the anterior (front) of the lower shin and ankle
• Increased with forced dorsiflexion and passive external rotation of the foot
• Over the tibiofibular ligaments, which are also tender to touch

People who suffer high ankle sprains will demonstrate an inability or unwillingness to put weight on that leg, especially right after the injury occurs. Weightbearing wedges the talus into the ankle joint, forcing the fibula laterally and stretching the sprained ligaments and syndesmosis, causing intense pain.

What to do

You should go see a doctor shortly after your injury if you suspect that you have a high ankle sprain, for a couple of reasons: (1) to make sure you don’t have a fracture in the area, (2) to check for a cartilage injury to the dome of the talus inside the ankle joint, and (3) to get a walking boot and/or crutches to facilitate healing and minimize the spreading effects caused by weight-bearing.

High ankle sprains are very slow to respond to conservative care and take significantly longer to heal properly than lateral ankle sprains, but they can still benefit from some basic initial treatment.

Initial Treatment

Right after your injury (and while you’re waiting to see the doctor) there are a few things you can do to reduce your symptoms and facilitate the healing process.

These initial treatments are the same as for most other non-catastrophic acute injuries. The critical components to initial treatment for high ankle sprains are being non-weightbearing and RICE (rest, ice, compression, elevation). However, until an x-ray rules out fractures, you need to use caution when applying compression to your foot, ankle, and lower leg. If compression causes pain, ice and elevation can still be performed regularly to minimize swelling. Anti-inflammatories (ibuprofen, Aleve, Advil – NOT Tylenol/acetaminophen) can also be used, but always follow dosing instructions on the label and be certain you don’t mix medications with the same active ingredients/drugs.

Prognosis

High ankle sprains require a significantly longer amount of time for full recovery when compared with lateral ankle sprains. High ankle sprains require an extended period of non-weightbearing (usually in a walking boot and/or on crutches). It often takes several months to return to full activity. Female ballet dancers who have had a previous high ankle sprain may notice a feeling of instability when en pointe, since the loosened anterior tibiofibular ligament will not restrict the anterior displacement of the talus that naturally occurs when the foot is in this position like it normally does.