Types of Fibula Fractures

What You Should Know About a Broken Fibula

broken fibula fracture
A fracture of the tibia (larger bone) and fibula (smaller bone). Photo © Jonathan Cluett, M.D.

A fibula fracture occurs when there is an injury to one of the two bones of the leg. The leg (the segment between the knee and ankle) is made up of two bones. The larger bone, the tibia, carries most of the body weight. The smaller bone, the fibula, is located on the outside of the leg.

The fibular bones starts just below the knee joint on the outside of the leg, and extends all the way down to the ankle joint.

The bone is a long, thin bone, hollow in its center. While the bone does little to support the weight of the body, the bone is a critical site of attachment for ligaments at both the knee and the ankle joint, and is also connected to the tibia bone by a thick ligament called the syndesmosis. While the fibula is an important bone, it is possible to excise much of the bone for surgical procedures where bone is needed elsewhere in the body. When these grafting procedures are performed, people are able to function very normally, despite missing a large part of the fibula bone.

Types of Fibula Fractures

There are a number of different types of injury to the fibula bone. For the purpose of this discussion, I will divide them into more manageable topics:

  1. Fibula fractures that occur as a result of injury to the ankle joint
  2. Fibula fractures that occur in conjunction with tibia fractures
  3. Stress fractures of the fibula

    There are not the only types of injury that can occur to the fibula, but account for the vast majority of injury to the fibula bone. By far the most common are injuries that occur when the ankle joint is damaged. Typically, the ankle buckles or is twisted, and as part of the injury, the fibula is damaged.

    Other types of fibula fractures are much less common.

    Ankle Injuries

    Fibula fractures typically occur as part of an ankle injury. Whenever a fibula fracture is found, the ankle should also be examined for possible injury. The most common type of fracture to occur to the fibula bone is an isolated injury to the end of the fibula bone at the level of the ankle joint. These injuries often occur in a similar manner to a badly sprained ankle, and often the injury can be treated similar to a badly sprained ankle.

    Fracture of the Fibula Without Other Injury to the Ankle
    Isolated fibular fractures, when the ankle joint is unaffected, often can be treated with simple protection. Known as a "lateral malleolus fracture," these injuries occur when the ankle twists or bends awkwardly, and the inner (medial) side of the ankle is unaffected. In these situations, a brace is sufficient to support the ankle. Crutches are often used for a few days or weeks to allow swelling and pain to subside. Once pain has lessened, patients begin rehabilitation to resume mobility exercises, strengthening and walking.

    Fibula Fracture With Associated Ankle Injury
    Fibula fractures that are associated with injury to inner side of the ankle, the medial malleolus or deltoid ligament, often require more aggressive treatment.

    In these situations, called "bimalleolar ankle fractures," surgery is usually necessary to stabilize the ankle joint. Without surgery, the ankle joint often heals in abnormal alignment, leading to the development of ankle arthritis.

    Another type of injury that can occur with a fibular fracture is damage to the syndesmosis of the ankle. The syndesmosis is the group of ligaments that hold the two bones of the leg together, just above the ankle joint. When the syndesmosis is damaged at the ankle, an injury that can occur along with a fibula fracture, surgery is often required to restore the alignment of the bones.

    Fibula Fractures with Tibial Shaft Fractures

    Severe injuries resulting from car crashes, sports injuries, or falls may lead to an injury of both the tibia and the fibula above the ankle joint. These injuries, often referred to as "tib-fib" fractures, typically require surgery to support the alignment of the leg. When the tibia is surgically repaired, the fibula does not normally require a separate surgery to align this bone. In some tib-fib fractures, a long-leg cast (thigh to foot) will provide necessary support without requiring the surgery.

    Stress Fractures of the Fibula

    In some people, particularly long-distance runners or hikers, the fibula may be injured as a result of repetitive stress. This type of injury is known as a stress fracture. The pain of a stress fracture may begin gradually. Usually the pain worsens with increasing levels of activity and is relieved by rest.

    What to Do When a Fibula Fracture Occurs

    As described, the treatment of fibula fractures depends on a number of different factors including where the fracture is located and what other injuries have occurred in association with the fracture. While isolated fibula fractures usually heal quickly, more complex injuries may require further treatment. Therefore, it is of critical importance that a medical professional familiar with the treatment of fibula fractures evaluate your injury, and ensure that appropriate treatment is recommended.

    Because only a small amount of body weight is transmitted through the fibula (most weight is transmitted through the larger tibia bone) many types of fibula fractures can be treated nonsurgically.  However, as described, fibula fractures that occur in association with other fractures or ligament injuries, often do require more invasive treatment.

    Sources:

    Fields KB, et al. "Fibular Fractures" UpToDate. January 2011.

    Continue Reading