Which of the following best describes a comminuted fracture?

A comminuted fracture is characterized by the bone breaking into multiple pieces, which aligns perfectly with the correct answer provided. This type of fracture typically occurs due to high-impact trauma, such as in vehicle accidents or severe falls. The bone is shattered, resulting in several fragments, making the treatment and healing process more complex compared to simple fractures.

In contrast, a clean break refers to a fracture that is straightforward and typically involves two main pieces of bone. A fracture occurring in a twisting motion pertains more to spiral fractures, which are distinct from comminuted fractures. Lastly, a fracture that affects only the cartilage does not involve the bone breaking and is not categorized as a comminuted fracture; this would relate more to conditions involving joint injuries rather than bony fractures. Thus, the defining feature of the comminuted fracture is its fragmentation into multiple pieces, making the correct answer accurate.