Motorcyclist’s fracture is ?
**Core Concept**
A motorcyclist's fracture refers to a specific type of fracture that occurs when a person falls from a motorcycle, typically landing on their outstretched hand. This type of fracture involves the distal radius and ulna, often resulting from a fall onto an outstretched hand.
**Why the Correct Answer is Right**
When a motorcyclist falls and lands on their outstretched hand, the force of the impact is transmitted up the forearm, leading to a fracture of the distal radius and ulna. This type of fracture is often associated with a "dinner fork" deformity, where the forearm is bent and the wrist is displaced. The distal radius and ulna are commonly fractured due to the direct force applied to the wrist during the fall.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the type of fracture that occurs in a motorcyclist's fall. The mechanism of injury is specific to a fall onto an outstretched hand.
**Option B:** This option is incorrect because it is a type of fracture that occurs due to a different mechanism of injury, such as a direct blow to the elbow.
**Option C:** This option is incorrect because it is a type of fracture that occurs due to a different mechanism of injury, such as a fall onto an outstretched arm.
**Option D:** This option is incorrect because it is a type of fracture that occurs due to a different mechanism of injury, such as a direct blow to the wrist.
**Clinical Pearl / High-Yield Fact**
A motorcyclist's fracture is often associated with a "dinner fork" deformity, which is a characteristic sign of this type of fracture. This deformity occurs due to the displacement of the distal radius and ulna.
**Correct Answer:** B. Colles' fracture.