Which type of fracture is suspected when a patient falls on an extended wrist?

A Colles' fracture is commonly suspected when a patient falls on an extended wrist. This type of fracture typically occurs in the distal radius bone of the forearm, near the wrist, and is characterized by a fracture that results in dorsal angulation and often dorsal displacement of the distal fragment. The mechanism of injury—landing on an outstretched hand—causes significant force transmission through the wrist, leading to this specific type of fracture.

In contrast, a scaphoid fracture, while also associated with wrist injuries, generally occurs when there is a direct impact to the wrist rather than extended wrist loading. A Boxer's fracture typically involves the fifth metacarpal and is commonly the result of punching an object, not from a fall on the wrist. A comminuted fracture involves the bone breaking into several pieces, which can occur from various traumatic forces but is not specifically linked to the mechanism of falling on an extended wrist. Thus, the characteristics and mechanisms of a Colles' fracture align most closely with the scenario described.