This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lower limb 1, Subject name: Anatomy
A 75-year-old man is transpoed to the emergency depament with severe pain of his right hip and thigh. A radiographic examination reveals avascular necrosis of the femoral head. Which of the following conditions most likely occurred to produce avascular necrosis in this patient?, 
Select and explain. 
A. Thrombosis of the obturator aery, B. Interochanteric fracture of the femur, C. Intracapsular femoral neck fracture, D. Comminuted fracture of the extracapsular femoral neck
C: Intracapsular femoral neck fracture
Answer: C: Intracapsular femoral neck fracture 
Explanation: An Intracapsular femoral neck fracture causes Avascular Necrosis of the Femoral Head because the fracture damages the radicular branches of the Medial and Lateral Circumflex Aeries that pass beneath the Ischiofemoral ligament and pierce the femoral neck. Comminuted fracture of the Extracapsular Femoral Neck would not ordinarily imperil the vascular supply.