A broken ankle is a fracture to one or more of the bones that make up the ankle joint.
Four bones connect in different ways to form what is called the ankle joint, although there are actually three joints within the ankle structure. The inferior tibiofibular joint is the connection between the lower parts of the tibia (shinbone) and fibula (the outer bone of the shin). The talocrural joint, often called the true ankle joint, is formed where the distal ends of the tibia and the fibula enclose the upper surface of the talus (one of the bones in the hind part of the foot). Under the true ankle joint is the third joint, known as the subtalar joint, where the talus rests on top of the calcaneus (heel bone).
The bones and joints are held in position and supported by ligaments that are strong ropes of connective tissue attaching bone to bone, tendons that run from the leg muscles down to the bones of the ankle and foot, and a band of connective tissue between the tibia and fibula called the interosseous membrane.
A broken ankle results in instability of any these joints, making weight bearing difficult or impossible until the fracture or fractures have healed.
An ankle can be fractured in many ways. Simply rolling the foot over or twisting it beyond its normal range of motion by tripping or falling can be enough to dislocate the joint or break a bone. During a dislocation a ligament can be torn away from the bone, pulling off a piece of bone with it. Blunt force or other trauma, such as motor vehicle accidents, can result in crush injuries to the ankle.
- Severe pain immediately upon injury
- Swelling, tenderness to the touch, and bruising
- Inability to bear weight on the foot
- Possible deformity of the ankle
A severely sprained or dislocated ankle can produce similar symptoms to a fractured ankle, so proper diagnosis is important.
Your doctor will ask for your medical history, including any previous ankle injuries. The circumstances of your current injury will be discussed, and the type and severity of your symptoms. Your ankle will be physically examined and possibly manipulated to help the doctor determine the type and extent of your injury.
X-rays are typically taken, as these will clearly show any fractures. Often X-rays will be taken of your leg and foot as well, in order to rule out other injuries. A stress test involves taking a special X-ray while the doctor puts pressure on a certain area of the ankle. This test can help determine whether surgery is needed. CT (computerized tomography) or MRI (magnetic resonance imaging) scans may be taken to provide more detailed images of the ankle bones and soft tissues.
Initial treatment for a broken ankle is to place the ankle in a splint. This will provide support while allowing the swelling to subside.
Further treatment will depend on the type and severity of the fracture. Ankle fractures often involve more than one bone and can also damage ligaments and tendons.
Lateral Malleolus Fracture
The distal (lower) end of the fibula has a bump that forms the outer anklebone, called the lateral malleolus. This can be fractured at various levels. Surgery to realign displaced bone fragments and hold them in place with orthopedic fixing devices may be required if the ankle is unstable. Otherwise, the ankle may be supported with a short leg cast. Regular X-rays would be taken to ensure the bones remained in position. Your doctor may allow you to place weight on the ankle immediately, or you may have to use crutches for up to six weeks.
Medial Malleolus Fracture
On the inner side of the ankle, the distal end of the tibia forms the medial malleolus, the inner anklebone. Fractures to this area often happen in conjunction with injury to other parts of the ankle. A non-displaced fracture will usually be treated with a short leg cast or brace, regular X-rays, and no weight bearing for about six weeks. Occasionally a non-displaced fracture will need surgery to allow earlier movement of the ankle and to reduce the risk of the bone pieces failing to unite.
Posterior Malleolus Fracture
Usually injured in conjunction with another bone or soft tissue structure, the posterior malleolus is at the back of the tibia. The joint may be unstable if the piece of broken bone is large, in which case surgery would be necessary. A stable fracture can be treated with a brace or short leg cast and the use of crutches for six weeks.
This injury usually results in an unstable ankle with two bones, normally the lateral and medial malleoli, broken. A bimalleolar equivalent fracture involves one broken malleolus together with an injury to the medial ligaments on the inside of the ankle. Surgery is nearly always needed to repair these fractures.
With this type of fracture all three malleoli are broken. As with bimalleolar fractures, these injuries make the ankle unstable and surgery is nearly always necessary.
Syndesmotic Injury (High Ankle Sprain)
An injury to the syndesmotic ligaments or interosseous membrane of the ankle is often treated in the same manner as a fracture, as the ankle is often unstable. High ankle sprains take longer to heal than the more common lateral ankle sprain. If there are associated fractures with the syndesmotic injury, prognosis is very poor without surgical repair.
Ankle injuries take a long time to heal fully; at least six weeks for the bones to heal and longer for the ligaments and tendons. Some people find that it may be two years before they are able to walk without limping. Your doctor will tell you when you are able to start moving your ankle again, and at that point you can begin rehabilitation. Range of motion exercises will increase flexibility. When you can put weight on your foot, strengthening exercises will help you get back to your normal activities. It is extremely important to follow medical advice about when to start exercising, and then to do the exercises. Beginning too soon can lead to displacement of the bone fragments and the need to begin treatment again. Not doing the exercises may result in permanent stiffness and weakness of the ankle.
There are different types of brace and support that you can wear to help you during the initial stages of rehabilitation, and when you resume sporting activities. Your doctor or physical therapist will advise you on the best for your particular ankle fracture.