What type of fracture is characterized by posterior displacement of the distal radius and a fracture of the ulnar styloid process?

• A. Smith fracture
• B. Colles fracture
• C. Greenstick fracture
• D. Buckle fracture

Answer: (B)

A fracture characterized by posterior displacement of the distal radius, coupled with a fracture of the ulnar styloid process, is specifically known as a Colles fracture. This type of injury typically occurs as a result of a fall on an outstretched hand, where the wrist extends at the moment of impact. The force of the fall causes the distal radius to fracture and displace posteriorly, leading to the characteristic "dinner fork" or "bayonet" appearance of the wrist.

In the context of the other types of fractures listed: a Smith fracture involves fracture and anterior displacement of the distal radius; a Greenstick fracture primarily describes an incomplete fracture seen commonly in children, characterized by bending and an incomplete break; and a buckle fracture, also referred to as a torus fracture, involves a compression of the bone, often seen in pediatric patients, that results in a bulging or buckling of the bone rather than a clean break.

Understanding the specific characteristics and mechanics of the Colles fracture is fundamental for diagnosing and treating wrist injuries effectively in radiography and clinical practice.