This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Orthopaedics
A 45-year-old was given steroids after renal transplant. After 2 years he had difficulty in walking and pain in both hips. Which one of the following is most likely cause? 
Select and explain. 
A. Primary Osteoarthritis, B. Avascular necrosis, C. Tuberculosis, D. Aluminum toxicity
B: Avascular necrosis
Answer: B: Avascular necrosis 
Explanation: Ans. B. Avascular necrosisMnemonic for causes of avascular necrosis other than fracture - SCLERAa. S-Steroidsb. C-Caisson's diseasec. LE - Lupus Erythematosusd. R-Radiatione. A-Alcohol