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: Surgery
Snowstorm appearance of knee joint with multiple loose bodies are seen in? 
Select and explain. 
A. Chondromalacia patellae, B. Ewing's sarcoma of knee joint, C. Fracture involving aicular surface, D. Synol chondromatosis
D: Synol chondromatosis
Answer: D: Synol chondromatosis 
Explanation: Most common cause of snowstorm appearence of knee joint with multiple loose bodies is synol chondromatosis. Most common cause of loose bodies in adolescents is Osteochondritis dessicans. Most common cause of loose bodies in elderly is Osteoahritis.