What characterizes a closed fracture?

A closed fracture is characterized by the skin remaining intact over the site of the fracture. This definition highlights the key difference between closed fractures and open (or compound) fractures, where the bone breaks through the skin. In closed fractures, although the bone is broken, the surrounding soft tissues and skin are not compromised, allowing for a different healing process and reducing the risk of infection associated with open fractures.

The other options describe characteristics of different types of fractures or specific fracture patterns. For example, shattering into multiple fragments typically describes a comminuted fracture rather than a closed fracture. Piercing the skin indicates an open fracture, and a fracture along the bone's long axis suggests a specific type of orientation that could occur in various fracture types but does not define a closed fracture specifically. Understanding how a closed fracture is defined helps reinforce the importance of skin integrity in classifying fractures.