A 4 year boy is complaining of pain around elbow with the hand held in pronation with extension. X ray of the elbow joint is normal. What is the most probable diagnosis?
**Core Concept**
The most probable diagnosis in this scenario involves a condition affecting the elbow joint, specifically related to the growth plate. The patient's symptoms of pain around the elbow, with the hand held in pronation with extension, suggest an injury to the radial head or a related growth plate issue.
**Why the Correct Answer is Right**
The correct diagnosis is likely a radial head subluxation, also known as a "nursemaid's elbow." This condition occurs when the annular ligament surrounding the radial head becomes displaced, causing pain and limited mobility in the elbow. The mechanism of injury often involves a sudden pull on the extended arm, leading to the subluxation. The patient's symptoms and the normal X-ray result support this diagnosis.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because a medial epicondylitis, also known as golfer's elbow, typically presents with pain on the medial aspect of the elbow, not the radial head.
* **Option B:** This option is incorrect because a lateral epicondylitis, also known as tennis elbow, typically presents with pain on the lateral aspect of the elbow, not the radial head.
* **Option C:** This option is incorrect because a fracture of the radial head would likely be visible on an X-ray, which is not the case in this scenario.
**Clinical Pearl / High-Yield Fact**
Radial head subluxations are common in young children, especially those under the age of 5, and can often be reduced with a simple maneuver called the "supination-reduction maneuver."
**Correct Answer: C.**