The most common site of fracture neck of the femur that causes avascular necrosis is –
**Question:** The most common site of fracture neck of the femur that causes avascular necrosis is -
A. Proximal
B. Distal
C. Intertrochanteric
D. Subtrochanteric
**Core Concept:** Avascular necrosis, also known as osteonecrosis, is a condition characterized by the death of bone tissue due to reduced or no blood supply. Fractures in the neck of the femur can lead to avascular necrosis if not properly managed.
**Why the Correct Answer is Right:** Fractures in the neck of the femur can lead to avascular necrosis due to the close proximity of the fracture site to the femoral head, which contains a high concentration of blood vessels. When a fracture occurs in this area, it disrupts the blood supply to the femoral head, causing ischemia and eventually leading to avascular necrosis.
**Why Each Wrong Option is Incorrect:**
A. Proximal: Fractures in the proximal part of the femur (e.g., femur shaft) are less likely to cause avascular necrosis due to the larger diameter of the femur shaft and the presence of collateral blood vessels that maintain blood flow to the femoral head in case of injury.
B. Distal: Similar to option A, fractures in the distal part of the femur (e.g., femur shaft) are less likely to cause avascular necrosis due to the larger diameter and collateral blood vessels.
C. Intertrochanteric: Intertrochanteric fractures are also less likely to cause avascular necrosis because they involve the wider, more stable trochanteric region of the femur. The fracture site is less susceptible to disrupting the blood supply to the femoral head.
D. Subtrochanteric: Similar to options A, B, and C, fractures in the subtrochanteric region are less likely to cause avascular necrosis due to the larger diameter of the subtrochanteric bone and collateral blood vessels.
**Clinical Pearl:**
Proper management of fractures in the neck of the femur is crucial to prevent avascular necrosis. This includes immediate and proper reduction, fixation, and immobilization to maintain blood flow to the femoral head and prevent complications.