According to the American Academy of Orthopaedic Surgeons, more than 1 million people visited emergency rooms due to an ankle injury in 2003. Ankle fracture describes a wide range of injuries; a child twists her ankle sustaining a fracture or a young man falls off a roof breaking his ankle into many pieces with bone sticking out of the skin. Each type of ankle fracture has a different treatment and outcome. There are many different ways of classifying ankle fractures. The most common way to categorize types of ankle fractures is by how the injury occurred. After most ankle fractures , an orthopedic surgeon can look at the X-rays and know how the ankle was broken.
Ankle Anatomy
The ankle joint is composed of three bones: the tibia, fibula and talus. Fractures of the distal tibia and fibula are considered ankle fractures. The tibia is the larger bone and it is on the inside of the leg. It forms the roof of the ankle joint. Two portions of the tibia extend down. On the inside of the ankle is the medial malleolus and in the back is the posterior malleolus. The fibula sits on the outside of the leg. Its lower portion is called the lateral malleolus. The syndesmotic ligament holds the tibia and fibula together. The top of the talus is curved, allowing it to rotate up and down. Although the talus s a key part of the ankle joint, talus fractures are considered foot fractures.
Twisting Injury
Most ankle fractures happen after a twisting fall. Surgeons describe them in terms of how the foot was placed during the fall. The pattern of the bone fractures indicate if the foot as in supination/pronation, eversion/inversion, and abduction/adduction. Depending of the force and type of the twisting injury, one, two, or all three malleolli can be broken off. These fractures are also called lateral malleolar fractures, medial malleolar fractures, bimalleolar fractures or trimalleolar fractures. Bimalleolar fractues typically refer to fractures of the medial and lateral malleoli. The ligaments can be injured. If a ligament pulls off a small piece of bone, it is referred to as an avulsion fracture.
In addition to X-rays telling what type of twisting injury caused the the bones to be broken, the type of twisting fracture indicates which ligaments are torn. Depending on how many bones are broken and the ligament injuries, the treatment ranges from a splint to surgery. After surgery, weight bearing may be limited.
Impact, Pilon Fracture
A X-ray showing the talus pushed into the tibia indicates a high energy injury. After a fall from a height or in a car accident, the talus can be forced up into the tibia producing a "pilon fracture." The large forces involved usually causes the fibula to break and the tibia is broken into several pieces. According to the AAOS, this fracture is most common in 35- to 40-year-old males.
The Wheeless' Textbook of Orthopaedics, produced by Duke University, explains that this fracture usually requires surgery. Plates and screws may be put into the ankle or pins may be put into the leg and connected to an external fixator. Because the joint surface is damaged, patients often develop arthritis.
Open Wounds
The AAOS reports that open wounds are common with pilon fractures. They may occur with other types of fracture too. When fractured bone is exposed, it is called an open fracture. The fractured bone can create a small hole in the skin to a large wound. If a large amount of skin is removed by force, as in a motorcycle injury, it is called a degloving injury. Gunshots also create open wounds.
Antibiotics are used to treat open fractures. For larger open wounds, multiple surgeries may be performed to clean out the wound. In some cases muscle and skin may need to be moved over the bone.
Pediatric
Children tend to sustain different types of ankle fractures, since their bones are still developing. The bones grow from cartilage areas within the bones called growth plates. Under stress, fractures can occur across the growth plates. From ages 10 to 16 years, the growth plates become solid bone. Tillaux and tri-plane are two fractures that occur only during the time tibia growth plates are closing.
Most children's fractures are casted. The treatment for children's fractures must take into account the remaining growth expected in the ankle.
References
- Duke University, Wheeless' Textbook of Orthopaedics: Ankle Fractures
- "American Academy of Orthopaedic Surgeons: Comprehensive Orthopaedic Review"; J. Lieberman, ed.; 2009
