American Board of Surgical Assistants (ABSA) Orthopedic Practice Test

In an unreduced Colle's fracture, which bone is displaced posteriorly?

1. Femur

2. Tibia

3. Radius

4. Ulna

The correct answer is: Radius

In the context of a Colle's fracture, the primary bone involved is the radius. This type of fracture typically occurs in the distal radius, often due to a fall onto an outstretched hand. In an unreduced Colle's fracture, the distal fragment of the radius is displaced posteriorly, which is why this scenario is significant for understanding the injury. The mechanism of injury and the position of the fragment can lead to complications if not addressed properly. Therefore, recognizing the proper alignment and displacement of the radius is critical in the diagnosis and treatment of this particular fracture type. The other bones listed—femur, tibia, and ulna—are not typically associated with the characteristic displacement seen in a Colle's fracture.