Which of the following fractures is characterized by an external wound?

A comminuted fracture involves the bone being broken into multiple pieces or fragments, typically as a result of high-impact trauma. While it can be severe, it does not necessarily involve an external wound, as the fracture can be closed and remain under the skin.

A complicated fracture refers to a fracture that is associated with additional injuries, such as damage to nearby nerves or blood vessels. It does not specifically denote the presence of an external wound, and thus, it may or may not be open or compound.

A greenstick fracture is an incomplete fracture commonly seen in children, where the bone bends and partially breaks. This type of fracture does not involve an external wound and is analogous to breaking a young twig. It remains within the skin and does not protrude.

An impacted fracture occurs when the ends of the broken bone are driven into each other, often due to compression forces. This type of fracture does not involve an external wound and is typically closed, making it distinct from a compound fracture.