Smith’s fracture involves which bone-
**Core Concept**
Smith's fracture is a type of fracture characterized by a volar (palmar) angulation of the distal radius, typically occurring when a fall onto an outstretched hand results in a displaced fracture. This fracture type is often confused with a Colles' fracture, which has a dorsal (posterior) angulation.
**Why the Correct Answer is Right**
The correct answer is linked to the mechanism of injury and anatomical location of the fracture. In Smith's fracture, the distal fragment is displaced volarly, indicating a disruption of the normal anatomical alignment of the distal radius. This is often due to a fall onto a flexed wrist, causing an axial load on the distal radius.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Smith's fracture specifically involves the distal radius, not the ulna. The ulna is a separate bone in the forearm that can be involved in other types of fractures.
**Option B:** This option is incorrect because Colles' fracture is a distinct type of fracture with dorsal angulation, whereas Smith's fracture has volar angulation. While both fractures occur at the distal radius, they have different characteristic features.
**Clinical Pearl / High-Yield Fact**
A key clinical feature of Smith's fracture is the presence of a "dinner fork" deformity, where the wrist takes on a characteristic angular appearance due to the volar displacement of the distal fragment.
**Correct Answer: C. Distal radius.**