Which of the following displacement is not seen in Colic’s fracture?
**Core Concept**
Colles' fracture is a type of fracture that occurs at the distal end of the radius bone in the forearm. It typically results from a fall onto an outstretched hand, leading to a displacement of the bone fragments. The displacement is characterized by a dorsal angulation of the distal fragment, which is often associated with a shortening of the radius.
**Why the Correct Answer is Right**
The correct displacement seen in Colles' fracture is a dorsal angulation of the distal fragment, which is usually around 10-20 degrees. This occurs due to the pull of the extensor muscles of the wrist, such as the extensor carpi radialis brevis, which causes the distal fragment to displace dorsally. The radius also exhibits a shortening of 2-3 mm due to the displacement.
**Why Each Wrong Option is Incorrect**
**Option A:** Volar angulation is actually seen in Smith's fracture, not Colles' fracture. Smith's fracture is a type of fracture where the distal fragment is displaced volarly, opposite to the dorsal angulation seen in Colles' fracture.
**Option B:** Varus displacement of the distal fragment is not typically seen in Colles' fracture. While some degree of varus displacement may occur, it is not a characteristic feature of this type of fracture.
**Option C:** Shortening of the radius is indeed seen in Colles' fracture, but the correct displacement is dorsal angulation, not shortening. Shortening is a secondary consequence of the dorsal angulation.
**Option D:** Dorsal angulation of the distal fragment is the correct displacement seen in Colles' fracture, making this option incorrect.
**Clinical Pearl / High-Yield Fact**
To remember the displacement in Colles' fracture, use the mnemonic "DAD" - Dorsal Angulation and Displacement. This will help you associate the correct displacement with the fracture.
**Correct Answer: D. Dorsal angulation of the distal fragment.**