25% of all musculoskeletal injuries are ankle sprains! What does spraining the ankle actually mean? The ankle joint is made up of three bones: the tibia, fibula and talus. These bones are held into proper position by a number of ligaments.
The soft tissues surrounding the joint help stabilize the bones so they do not move too much in the wrong directions. Sprains usually occur during athletic activities but sometimes we step down or trip on a rug and put abnormal pressures on our ankle. Most often, a sprain occurs when the foot gets tilted inward or inverted. These abnormal forces causes stretching or tears to the ligaments that stabilize the joint. The injured ligaments will lead to swelling, inflammation, and pain. If the injury is severe, there may be a fracture present. It is standard for doctors to order x-rays and do multiple different maneuvers to the foot and ankle to asses which ligaments are damaged and if any of the bones are broken. When no bones are involved, rest, ice, compression, elevation, and anti-inflammatory medication usually does the trick.
When a fracture occurs there may be need for surgical intervention. Many people recover from ankle sprains with no problems, but about 10% of ankle sprains do not improve with traditional therapy. In these patients, the ankle sprain was only part of the problem. Below the ankle is another joint between the talus and the calcaneus called the subtalar joint. Thus the talus bone is connected to both the ankle and the subtalar joint. You can imagine that if abnormal forces are put on the talus there will sometimes be damage to the ankle joint and the subtalar joint. Just as ligaments are torn or damaged at the ankle joint, ligaments can be damaged at the subtalar joint.
Unfortunately, it is nearly impossible to tell the difference between ankle instability and subtalar joint instability by physical evaluation. To evaluate the damage, radiographs have to be carefully evaluated and some non-traditional evaluations should be utilized. Placing the foot in specific forced positions is necessary to open up the joint spaces to assess the damage. These can be very painful and a local anesthetic may be necessary in order to complete the exam. Ultrasound has shown to be a great way to evaluate injuries, but not all medical care centers have this modality available. If this injury is caught early , the treatment is mostly non-surgical. Different immobilization devices and physical therapy can usually strengthen the ligaments. Occasionally the injury will become a chronic problem that requires surgery. Since this injury is hard to assess and difficult to differentiate from ankle joint injuries, your doctor may have a difficult time recognizing the issue. It is important to communicate your symptoms and pain as thorough as possible. Knowing how the injury occurred and the position your foot was in when the injury occurred can be very useful information for your doctor to determine what ligaments were injured. If you had an ankle sprain that doesn’t seem to be getting better, it may be an unstable subtalar joint that is the root of your problems.