Ankle Fracture Classifications

Ankle fractures and dislocations are a common injury that are treated by orthopaedic surgeons, emergency room physicians, and family physicians. The three bones that make up the ankle joint include the fibula, tibia and talus. These bones can be broken in a wide variety of fracture patterns that help to dictate different levels of care. Treatment can range from a simple cast or walking boot to surgical fixation with a wide variety of orthopaedic hardware.

Isolated Malleolar Fracture

An isolated malleolar fracture typically occurs at the lateral malleolus. The lateral malleolus is the end portion of the fibula bone that can be felt on the outside of the ankle joint. According to the “AAOS Comprehensive Orthopaedic Review,” surgery is required for around 11 percent of these fractures. These fractures can often be treated with a cast. A manipulation or reduction maneuver may be done prior to casting to improve the alignment of the bones. The site of the fibula fracture helps guide the physician as to whether the patient will need surgery.

An isolated malleolar fracture can occur at either the medial malleolus or posterior malleolus. These are uncommon as isolated injuries. The medial malleolus is the end portion of the tibia that is felt on the inside part of the ankle. The posterior malleolus refers to the back portion of the tibia at the ankle joint.

Bimalleolar Fracture

A bimalleolar fracture involves both the medial and the lateral malleolus. The ankle is typically not stable with this type of fracture. There is usually significant ligament injury along with the fracture. There can often be a dislocation of the ankle as well. Treatment is typically surgical, although initial treatment may be with a splint until the swelling subsides prior to having the surgery.

Trimalleolar Fracture

A trimalleolar fracture refers to fractures of all three malleoli of the ankle: medial, lateral, and posterior. These fractures are also associated with significant ligamentous injuries. The trimalleolar fracture makes the ankle joint unstable and is often associated with a dislocation of the ankle joint. Surgery is usually indicated with placement of screws and plates to hold the fracture fragments back into place. Casting after a reduction maneuver may be performed prior to surgery as the surgeon waits for the swelling in the ankle to subside.

Tibial Plafond Fracture

The tibial plafond fracture is a fracture of the terminal tibia that extends into the ankle joint. According to the “AAOS Comprehensive Orthopaedic Review,” these fractures make up less than 10 percent of lower extremity injuries. There are a wide variety of fracture patterns. There may be impaction of the tibia bone into the talus resulting in a very unstable joint. Surgery is usually required to restore proper ankle alignment.

About this Author

Gregory Waryasz has been a writer since 2004. His work has appeared in “Dynamic Medicine,” “Athletic Therapy Today” and the “Journal of the American Academy of Nurse Practitioners.” He is currently an orthopaedic surgery resident at Brown University/Rhode Island Hospital. Waryasz is also certified as a strength and conditioning specialist. He has a Doctor of Medicine from Tufts University.