A fractured calcaneus refers to an injury to which body part?

A fractured calcaneus specifically refers to an injury of the heel bone, which is known as the calcaneus. The calcaneus is the largest bone in the foot and forms the foundation of the rear part of the foot structure, playing a critical role in walking and standing. Fractures can occur in this area due to falls, high-impact events, or trauma, often resulting in significant pain and mobility issues.

While the foot bones are a broader category that includes the calcaneus, the specific identification of the calcaneus makes "heel bone" the most accurate response. The outer ankle bone refers to fibular structures, and the brachial artery is unrelated as it pertains to the arm, not the foot. Hence, recognizing the calcaneus as the heel bone clarifies the precise anatomical focus of the question.