This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Synovial Chondromatosis, Subject name: Orthopaedics
[{'content': 'Snowstorm appearance of knee joint with multiple loose bodies is seen in? \nSelect and explain. \nA. chondromalacia patellae, B. Ewings sarcoma of knee joint, C. Fracture involving articular surface, D. Synovial chondromatosis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: ANSWER: (D) Synovial chondromatosisREF: The Journal of bone and joint surgery: British volume: Volume 71, Pages 549-912, http:// www.springerlink.com/content/17m54n357304205m/Snowstorm knee:Seen in Synovial chondromatosisTraumatic etiologyJoint effusionNumerous brilliant white rice-grain size free bodies in arthroscopy (not radiographically)', 'role': 'assistant'}]