What is the primary characteristic of a closed/simple fracture?

A closed/simple fracture is characterized by the skin remaining intact. This means that while the bone has been broken, there is no external wound or communication with the outside environment. This is significant in the context of healing and treatment, as it typically results in a lower risk of infection, and may allow for different management approaches compared to open fractures, where the bone breaks through the skin.

The other options do not correctly describe the primary characteristic of a closed/simple fracture. For instance, a completely broken bone could refer to either closed or open fractures, and the presence of bone protruding through the skin specifically describes an open fracture. Additionally, while severe bleeding can occur with fractures, it is not a defining characteristic of a closed/simple fracture, as the skin's integrity helps to minimize this risk. Hence, the central aspect of a closed/simple fracture is indeed the conservation of the skin's integrity.