An elderly woman was admitted with a fracture of the neck of right femur which failed to unite. On examination an avascular necrosis of the head of femur was noted. The condition would have resulted most probably from the damage to
**Core Concept**
The question is testing the understanding of the blood supply to the femoral head and the consequences of its disruption. The femoral head receives its blood supply primarily from the medial and lateral circumflex femoral arteries, which form an anastomotic network around the femoral neck. This network is critical for maintaining the viability of the femoral head.
**Why the Correct Answer is Right**
Avascular necrosis of the femoral head occurs when the blood supply to the bone is disrupted, leading to tissue death and collapse. In this case, the fracture of the neck of the femur likely damaged the blood vessels supplying the femoral head, resulting in avascular necrosis. The medial circumflex femoral artery is particularly vulnerable to injury due to its location and course, making it a likely culprit in this scenario.
**Why Each Wrong Option is Incorrect**
**Option A:** The lateral circumflex femoral artery is also a potential source of blood supply to the femoral head, but it is less commonly implicated in cases of avascular necrosis.
**Option B:** The deep artery of the thigh is not directly involved in supplying the femoral head.
**Option C:** The superior and inferior gluteal arteries primarily supply the gluteal muscles and do not contribute significantly to the blood supply of the femoral head.
**Clinical Pearl / High-Yield Fact**
In cases of femoral neck fractures, it is essential to preserve the blood supply to the femoral head to prevent avascular necrosis. This can be achieved by minimizing the dissection of the soft tissues and avoiding excessive retraction of the femoral vessels.
**Correct Answer:** C.