Ankle Fracture, Causes and Symptoms
An ankle fracture is a broken ankle. It occurs when one or several bones that make up the ankle joint – and possibly its ligaments – are broken at or near the joint. Three bones function together in order to make the ankle joint: the shinbone (known as the tibia), the calf bone (known as the fibula) and the talus (the bone at the top of the foot). 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.
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 activeness of older people that has accompanied the aging of the “baby boomers.” Our emergency rooms saw 1.2 million visits in 2003 alone because of ankle fractures. 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.
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 human locomotion and balance. The ankle and surrounding area is composed of:
- The tibia (the shinbone, which carries 90% of the weight load the lower leg takes on)
- The fibula (the calf bone, which carries 10% 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)
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.
Causes of Ankle Fractures
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, it can cause an ankle fracture.
Ankle roll – If your foot rolls up onto its side while you are putting substantial weight on it, it can cause an ankle fracture.
A trip or a fall – If you unexpectedly lose your balance and awkwardly try to catch yourself with your feet, it can cause an ankle fracture.
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, you risk ankle fracture.
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, your ankle can be broken.
Symptoms of Ankle Fractures
While different types of ankle fracture have different symptoms, the symptoms of the condition are generalizable: You will feel extreme pain in the ankle, and this pain may “radiate” out to the knee and foot. Your ankle will swell; your leg may swell as well. You will likely not be able to walk, though you can walk with some not-so-severe breaks. Don’t use walking as a test for whether you have a broken ankle or not. 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. This type of ankle fracture can lead to serious infection.
The following are common ankle fracture symptoms:
- Inability to walk without aid
The symptoms of ankle fracture may be mistaken for the symptoms of other medical conditions (talus fracture, sprained ankle, etc.). Make sure you consult a doctor in order to determine if you have an ankle fracture and get the appropriate treatment.
The multidisciplinary team of orthopaedic experts at North Shore-LIJ Orthopaedic Institute's Trauma Services in New York treats Ankle Fractures as well as a broad range of conditions that affect the bones within the body.