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

A comminuted fracture involves the bone being shattered into several pieces, but it does not necessarily create an external wound. The primary characteristic of a comminuted fracture is the fragmentation of the bone, which can occur without any skin breach.

A complicated fracture refers to any fracture that is associated with additional injuries or complications, such as damage to surrounding tissues or organs. While it may involve severe injuries, it does not specifically denote an external wound like a compound fracture does.

A greenstick fracture is an incomplete fracture that occurs primarily in children, where the bone bends and partially breaks, similar to how a green twig breaks. This type of fracture does not involve the skin and thus lacks the external wound characteristic of compound fractures.

An impacted fracture occurs when one bone fragment is driven into another, which may lead to significant injury but does not involve an external wound. The defining feature of an impacted fracture is the compression of the bone rather than a breach of the skin.