Avascular necrosis is commoner in: March 2012
**Core Concept**
Avascular necrosis (AVN) occurs due to the interruption of blood supply to a bone, leading to ischemic damage and eventual necrosis of the affected bone tissue. This condition is often associated with various underlying factors, including trauma, corticosteroid use, and certain systemic diseases.
**Why the Correct Answer is Right**
The correct answer is related to the fact that AVN is more commonly seen in the femoral head, particularly in young adults. This is due to the high density of fatty marrow in the femoral head, which is more susceptible to ischemic damage when the blood supply is compromised. The femoral head receives its blood supply from the medial and lateral circumflex femoral arteries, which can be easily damaged in certain traumatic injuries or pathological conditions.
**Why Each Wrong Option is Incorrect**
* **Option A:** Not specifically related to the condition of avascular necrosis, as it does not directly impact the blood supply to the bone.
* **Option B:** May be related to other conditions, but not specifically to avascular necrosis, which is the focus of this question.
* **Option C:** While certain systemic diseases may contribute to the development of AVN, this option is too broad and does not specifically address the condition.
* **Option D:** Not directly related to the condition of avascular necrosis, as it does not impact the blood supply to the bone.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the risk of avascular necrosis is higher in young adults, particularly in those with a history of corticosteroid use or certain traumatic injuries.
**Correct Answer:** B. Femoral head.