General Principles of Talus Fractures

The talus is divided into three parts, the head, neck, and body, and two processes, lateral and posterior. It has five articular surfaces, all of which have a weight-bearing function. Two-thirds of the talus is covered with articular cartilage, and no muscles insert or originate on it. The talar neck is the weakest portion of the talus because of its porosity for vascular ingrowth and its small cross-sectional area. The talus has a rich blood supply that arises from branches of the posterior tibial, dorsalis pedis, and peroneal arteries. Talar neck fractures are high-energy injuries that result from a dorsally directed force applied to the plantar surface of the foot distal to the talus. Talar body fractures involve both the subtalar and tibiotalar joints and are usually caused by in-line axial compression. Finally, talar head fractures are lower-energy talus injuries caused by shear or compression of the navicular against the talar head. Radiographic evaluation of suspected talus injuries begins with AP, lateral, and oblique views of the foot and ankle. Additional imaging includes Canale and Broden views as well as a thin-cut CT scan for both surgical planning and identification of subtle injuries.