Tardy ulnar nerve palsy is commonly seen in:September 2008
**Core Concept**
Tardy ulnar nerve palsy is a type of ulnar nerve palsy that occurs secondary to a pre-existing deformity or injury, leading to a delayed onset of symptoms. This condition typically affects the hand and fingers, resulting in weakness, numbness, and clawing of the ring and little fingers.
**Why the Correct Answer is Right**
Tardy ulnar nerve palsy is often associated with cubitus varus deformity, a condition where the elbow is bent at an angle greater than 5 degrees. This deformity can lead to stretching and compression of the ulnar nerve over time, resulting in the characteristic symptoms of ulnar nerve palsy. The ulnar nerve is particularly susceptible to injury in this region due to its anatomical course, which involves a long, winding path through the cubital tunnel and a narrow groove on the medial epicondyle.
**Why Each Wrong Option is Incorrect**
* **Option A:** While other types of ulnar nerve palsy, such as cubital tunnel syndrome, can be caused by compression of the ulnar nerve at the elbow, tardy ulnar nerve palsy is specifically associated with a pre-existing deformity or injury.
* **Option B:** Radial nerve palsy is a separate condition that affects the radial nerve, which is responsible for wrist and finger extension. While both nerves can be affected in the same region, they have distinct functions and are not interchangeable.
* **Option C:** Ulnar nerve palsy can be caused by a variety of factors, including direct trauma, compression, or entrapment. However, tardy ulnar nerve palsy is specifically characterized by a delayed onset of symptoms following a pre-existing deformity or injury.
**Clinical Pearl / High-Yield Fact**
It's essential to differentiate between tardy ulnar nerve palsy and other types of ulnar nerve palsy, as the underlying cause and treatment approach may differ. A thorough medical history and physical examination are crucial in diagnosing this condition.
**Correct Answer: C. Ulnar nerve palsy is commonly seen in patients with a pre-existing deformity or injury, particularly cubitus varus deformity.