This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Orthopaedics
A thirty one year old male with neprhrotic syndrome complains of pain in right hip joint of 2 months duration. The movements at the hip are free but painful terminally. The most likely diagnosis is - 
Select and explain. 
A. Tuberculosis of hip, B. Avascular necrosis of femoral head, C. Chondrolysis of hip, D. Pathological fracture of femoral neck
B: Avascular necrosis of femoral head
Answer: B: Avascular necrosis of femoral head 
Explanation: This patient has : - 


Nephrotic syndrome (must be taking steroids)
Pain in hip
Terminal restriction of movements (in AVN, initially movements are restricted terminally only).


The diagnosis is AVN of Hip.
In all other three options movements of hip are grossly restricted (not terminally).