**Question:** Motorcyclist's fracture

**Core Concept:** Motorcyclist's fracture is a type of high-energy forearm fracture that occurs due to a twisting injury. The fracture is characterized by a spiral fracture pattern along the long axis of the radius and involves both cortices.

**Why the Correct Answer is Right:**
The correct answer, **D**, describes the correct fracture pattern associated with a motorcyclist's fracture: a spiral fracture along the long axis of the radius, involving both cortices. This type of injury typically occurs in a motorcycle accident, hence the term "motorcyclist's fracture." The force applied during a high-energy injury causes the fracture to occur along the long axis of the radius, resulting in a spiral pattern involving both the inner and outer cortices of the bone.

**Why Each Wrong Option is Incorrect:**
A. This option does not describe the fracture pattern typical of a motorcyclist's fracture. A spiral fracture along the long axis of the radius, involving both cortices, is essential for this type of injury.
B. Although fractures can occur in other locations, this option does not accurately represent the motorcyclist's fracture. The fracture pattern mentioned is not specific to this type of injury.
C. This option does not describe the typical fracture pattern associated with a motorcyclist's fracture, which involves both cortices along the long axis of the radius in a spiral pattern.

**Clinical Pearl / High-Yield Fact:**
High-energy fractures, like the motorcyclist's fracture, should raise suspicion for a mechanism of injury in the given scenario (e.g., motorcycle accident). A thorough history and physical examination, including assessment of the mechanism of injury, can help guide clinical decision-making and prevent misdiagnosis.

**Correct Answer:** D: The correct answer highlights the key fracture pattern of a motorcyclist's fracture: a spiral fracture along the long axis of the radius, involving both cortices. This description accurately represents the typical injury sustained in a motorcycle accident, which is the context provided in the question.