As the largest tarsal bone and the most inferior bone in the body, the calcaneus is responsible for supporting the axial load from the weight of the body. It is most commonly fractured after a fall from a height in which axial loads exceed its support capacity. Calcaneal fractures account for 60% of all tarsal fractures. Conventional radiography is commonly used for initial evaluation of calcaneal injury but has the typical disadvantages of two-dimensional imaging. Modern assessment of calcaneal fractures relies heavily on multidetector computed tomography (CT), which allows better visualization and characterization of fracture lines and fragment displacement. Calcaneal fractures observed at CT have been divided into intra- and extraarticular fractures on the basis of subtalar joint involvement. The Sanders classification system for intraarticular fractures is the most commonly used system because it correlates with clinical outcomes and involves less interobserver variability. The classification of extraarticular fractures has been less controversial and makes use of anatomic landmarks on the calcaneus to divide the bone into anterior, middle, and posterior areas. Soft-tissue involvement is an important aspect of calcaneal fracture assessment because it has been linked with poor functional outcomes. Familiarity with the normal anatomy of the calcaneus, the classification of calcaneal fractures, and the various complications of these fractures is essential for treatment assessment, especially if surgical intervention is required.
RSNA, 2011