Patent Education

STRUCTURE

One mile of walking can generate more than 60 tons of stress on each foot. It is not surprising then that more than 20% of musculoskeletal problems seen affect the lower extremity. More than 25,000 people sprain an ankle each day in the United States, not all of which are simple injuries. Sometimes up to 40% of these patients can have residual symptoms. Of course, not every "ankle sprain" really is an ankle sprain. There are other injuries that can occur and the following material will review this briefly.

The ankle is a connection between the leg and foot. It is the junction of three bones, the tibia, the talus and the fibula. The main articular portion really is between the talus and tibia. It is stabilized by multiple ligaments. On the outside, or lateral, part of the ankle the three prominent stabilizing ligaments are the anterior talofibular ligament, the calcaneofibular ligament, and the posterior talofibular ligament. On the medial, or inner, part of the ankle the deltoid ligament is the primary stabilizer. This is a broad, complicated and very strong ligament. Between the two leg bones, the fibula and tibia, the thick tissue holding those together is called the syndesmosis.

INJURIES

COMMON ANKLE SPRAIN
By far, most injuries occur to the ankle with an "inversion" or rolling in of the foot and ankle in a weightbearing position. It is common in soccer, basketball and football. Often times this is associated with a pop over the outer side of the ankle. There may be immediate swelling and an inability to walk. By far, most of these types of injuries will involve the anterior talofibular ligament ("ATFL") and possibly the calcaneofibular ligament. The pain is usually over the outside, or lateral, part of the ankle. Typically, the other structures are intact. The type and treatment for these types of injuries depends on the extent of the ligament tear and amount of instability. Often with mild ankle sprains they will respond well to icing, compression and elevation. Sometimes a brace, air stirrupor taping can be used to protect the ankle from repeated inversion injuries. For those with a more severe strain, they are sometimes immobilized in a cast or walking boot. In more severe chronic situations, when a patient has recurrent ankle sprains, they can undergo a small surgical procedure to repair their ligaments. By far, most people will get better with nonsurgical treatment. Physical therapy for instruction on strengthening one’s ankle is also helpful at times

ANKLE SPRAIN / SYNDESMOSIS
Approximately 5% of all ankle "sprains" will involve the syndesmosis. This is the very thick tissue that attaches the end of the tibia to the fibula. A scenario for this injury is having one’s foot planted into the ground and having the body rotate the other way. For example, the left foot will be fixed on the ground and the body will rotate to the right causing an external rotation injury. Often these are extremely painful and typically hurt much worse than a typical ATFL strain. With a severe strain it is sometimes associated with a fracture to the upper fibula bone. The examination for a syndesmosis injury typically shows a different pain pattern than an ATFL sprain. External rotation of the ankle may cause a significant amount of pain on an exam. Inversion of the ankle may not be quite as tender as one would find with an ATFL tear.

ANKLE SPRAIN / DELTOID LIGAMENT
The deltoid ligament is a wide complex ligament over the inner part of the ankle. A sprain here can sometimes be associated with an ATFL sprain. Typically these indicate more severity to the injury than the usual ATFL sprain. An ankle deltoid ligament sprain coupled with an ATFL sprain takes longer to heal

ANKLE FRACTURE
Occasionally with an inversion injury that would normally cause an ankle sprain, a piece of bone can be pulled off. We refer to this as an avulsion fracture. Sometimes the ligament actually is stronger than the bony insertion point and an avulsion fracture will ensue. Often these can be treated conservatively either in a walking boot or an Air Cast. A more significant fracture may be treated with a cast or surgery. The bone usually fractured here is the end of the fibula which we call the "lateral malleolus.

LATERAL FOOT FRACTURE
The same mechanism that causes an ankle sprain can sometimes cause a fifth metatarsal fracture in the foot. This is a fracture that occurs in the outer part of the foot along the long metatarsal bone. These sometimes can be confused with a routine ankle sprain. Typically, however, the pain will be more along the side of the foot than in the ankle area.

OTHER INJURIES
Other ankle injuries that can occur include calcaneus or talus fractures, an osteochondral fracture (a bony cartilage injury in the weightbearing portion of the talus), peroneal tendon tears or subluxations, and subtalar injuries.

DIAGNOSIS

The diagnosis of ankle injuries is made primarily with examination. Depending on the amount of swelling, the location of pain, and the stability of the ankle on examination most diagnoses can clearly be made. When there is an area of bony tenderness aside from the usual ankle sprain pain or an indication of instability, x-rays are often helpful.

TREATMENT

The treatment of an ankle injury depends on the diagnosis of the exact problem. Typically, elevation, ice, and anti-inflammatory medications are helpful in all these situations. Avoid the application of heat for at least two weeks. Sometimes taping or an air stirrup are helpful. For more severe strains a cast or walking boot can be used. Physical therapy for ankle strengthening and motion is often used for more severe injuries. For those ankles that are unstable on x-ray or have an unstable fracture, surgery is indicated. In those instances where someone has recurrent ankle instability despite rehabilitation and conservative treatment, surgical repair of their ligaments can be performed.