What is an ankle fracture?
An ankle fracture occurs when one or more than one bone that makes up the ankle joint—and possibly its ligaments—breaks at or near the joint.
Every year, 184 people out of every 100,000 sustain ankle fractures. This number has been going up (and the broken ankles have been getting more serious) in the last 30 years due to the increased activity of older people that has accompanied the aging of the “baby boomers.” Emergency rooms saw 1.2 million visits in 2003 because of ankle fractures alone.
Anatomy of the ankle
The ankle joint (also known as the talocrural joint) is the first weight-bearing joint in the body. Its health is key for the body's movements and balance. The ankle and surrounding area is composed of:
- The tibia (the shinbone, which carries 90 percent of the weight load the lower leg takes on)
- The fibula (the calf bone, which carries 10 percent of the weight load the lower leg takes on)
- The talus (the anklebone, which articulates with the tibia and the fibula at the ankle joint)
- The lateral collateral ligaments (ankle ligaments that connect to the fibula)
- The medial collateral ligaments (ankle ligaments that connect to the tibia)
The fibula articulates with the talus (that is, forms a joint with it) at one place, called the lateral malleolus; the tibia articulates with the talus at two places: the medial malleolus and the posterior malleolus. It is these malleoli that form the bony protrusions on either side of your ankle. The tibia and the fibula form a syndesmosis (that is, a ligament-bone connection) above the talus. The ankle joint and the tibia-fibula syndesmosis are both involved in the fracturing of an ankle.
Types of ankle fractures
Ankle fractures can be divided into five main types:
- Lateral malleolus fracture—The lateral malleolus is the point located on the outside of the leg where the fibula articulates with the talus. A lateral malleolus fracture is, strictly speaking, a broken distal fibula.
- Medial malleolus fracture—A medial malleolus fracture is a tibia fracture analogous to the fibula’s lateral malleolus fracture. It is a fracture of the distal tibia.
- Posterior malleolus fracture—It is very rare that only the posterior malleolus—the actual bony protrusion of the tibia—is broken.
- Bimalleolar fractures—If two anklebones are fractured, it is called a bimalleolar fracture. This is most often a combination of a lateral malleolus and a medial malleolus fracture. This type of fracture will lead to an unstable ankle.
- Trimalleolar fractures—If all three of the malleoli (the lateral, medial and posterior) have been broken, it is a trimalleolar fracture. This type of fracture will lead to an extremely unstable ankle.
The multidisciplinary team of trauma and fracture experts at Northwell Health Orthopaedic Institute treats ankle fractures as well as a broad range of conditions that affect the bones.
While different types of ankle fractures have different symptoms, there are several common symptoms across all types:
- Extreme pain in the ankle that may “radiate” out to the knee and foot
- Swelling in the ankle and, occasionally, leg
- Difficulty walking or complete inability to walk (do not use this as a test, as it can worsen the injury)
The symptoms of an ankle fracture may be mistaken for the symptoms of other medical conditions (talus fracture, sprained ankle, etc.). Make sure you consult a doctor to determine if you have an ankle fracture and get the appropriate treatment.
An ankle fracture is the result of too much stress being put on any or all of the bones of the ankle joint. The following are the causes of ankle fractures:
- Ankle twist—If your foot twists far to the side, pivoting around your ankle
- Ankle roll—If your foot rolls up onto its side while you are putting substantial weight on it
- A trip or a fall—If you unexpectedly lose your balance and awkwardly try to catch yourself with your feet
- Overextension of the ankle joint—If you try to swing your foot down too far in a parallel arc with your leg, as a ballerina might
- Extreme impact—If the joint sustains a severe blow, as it may if you come down on your feet from a height or are in an automobile accident
Without appropriate medical intervention and care, an ankle fracture can lead to arthritis. You have an especially high risk of eventually getting arthritis if, after the injury, your ankle looks misshapen. If the break is very severe, you might see a bone poking out of your skin. If this is the case, you must seek immediate medical care, as this type of ankle fracture can lead to serious infection.