Which of the following describes a compound fracture?

A compound fracture, also known as an open fracture, is characterized by the bone breaking in a way that it pierces through the skin. This type of fracture is significant because it poses a higher risk of infection due to the exposure of the bone and surrounding tissue to the external environment. In contrast, the other descriptions focus on different aspects of fractures that do not imply exposure of the bone to the outside world. A closed fracture (where the skin remains intact) would not be considered a compound fracture; likewise, a clean fracture or one fractured into multiple pieces does not inherently define a compound fracture unless the bone is also exposed. Therefore, the definition of a compound fracture aligns precisely with the presence of the bone protruding through the skin, underlining its critical distinction from other fracture types.