In which of the following condition is tardy ulnar nerve palsy seen?
**Core Concept**
Tardy ulnar nerve palsy is a delayed onset ulnar nerve dysfunction, typically occurring years after an initial injury or trauma. It is characterized by weakness and atrophy of the intrinsic muscles of the hand, leading to a characteristic claw hand deformity.
**Why the Correct Answer is Right**
Tardy ulnar nerve palsy is often seen in cases of Cubitus Varus deformity, a condition resulting from a supracondylar fracture of the humerus in children. The deformity leads to a gradual stretching and elongation of the ulnar nerve, causing progressive damage to the nerve and resulting in tardy ulnar nerve palsy. The mechanism involves chronic traction on the ulnar nerve, leading to demyelination and axonal degeneration.
**Why Each Wrong Option is Incorrect**
* **Option A:** Tardy ulnar nerve palsy is not typically seen in cases of Cubitus Valgus deformity, which is a result of a different type of supracondylar fracture.
* **Option B:** Radial nerve palsy is a different condition that affects the radial nerve, not the ulnar nerve, and is characterized by wrist drop and loss of extension of the wrist and fingers.
* **Option D:** Median nerve palsy would affect the muscles of the thenar eminence and the lateral two digits, leading to a different set of symptoms and signs.
**Clinical Pearl / High-Yield Fact**
Tardy ulnar nerve palsy is a classic example of a delayed onset complication of a childhood injury, emphasizing the importance of long-term follow-up and monitoring of patients with a history of supracondylar fractures.
**Correct Answer: C. Cubitus Varus deformity.**