Late complication of elbow dislocation –
**Core Concept**
Elbow dislocation is a complex injury that can lead to various late complications due to the involvement of multiple ligaments, bones, and nerves. The most common late complication of elbow dislocation is cubitus varus, also known as gunstock deformity, which is a valgus deformity of the elbow.
**Why the Correct Answer is Right**
Cubitus varus occurs due to the malunion of the medial epicondyle fracture, leading to an imbalance in the medial and lateral columns of the elbow. This results in a valgus deformity, where the distal humerus is displaced laterally, causing the forearm to be positioned away from the midline of the body. The medial collateral ligament is stretched or torn, leading to instability of the elbow joint.
**Why Each Wrong Option is Incorrect**
* **Option A:** Radial head fracture is a common complication of elbow dislocation, but it is not the most common late complication.
* **Option B:** Ulnar nerve palsy can occur due to the compression or stretching of the nerve during the injury, but it is not a direct late complication of elbow dislocation.
* **Option D:** Osteoarthritis can develop as a late complication of elbow dislocation, but it is not as common as cubitus varus.
**Clinical Pearl / High-Yield Fact**
It's essential to note that the position of the forearm at the time of injury can influence the development of cubitus varus. A pronated forearm is more likely to result in cubitus varus, while a supinated forearm is less likely.
**Correct Answer:** C.