Which of the following is a defining characteristic of a comminuted fracture?

• A. Bone fragments that become exposed to the outside environment.
• B. The bones are broken into 3 or more pieces because of a traumatic event.
• C. A bone fragment is broken off from the rest of the bone at a tendon. 
• D. The bone is broken straight across at an acute angle to the length of the bone.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the term 'comminuted fracture' by breaking down the word: 'comminuted' means 'broken into small pieces.' This indicates that the bone is shattered or broken into multiple fragments.
2. Step 2: Review the options given and identify which description matches the idea of a bone being broken into several pieces rather than just one or two.
3. Step 3: Recognize that a fracture where the bone is broken into three or more pieces is characteristic of a comminuted fracture, often caused by a high-impact traumatic event.
4. Step 4: Differentiate this from other types of fractures: for example, an open fracture involves bone fragments exposed to the outside environment, a chip fracture involves a fragment broken off at a tendon, and a transverse fracture is a straight break across the bone.
5. Step 5: Conclude that the defining characteristic of a comminuted fracture is the bone being broken into three or more pieces due to trauma.