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
[{'content': "A 60-year-old man with diabetes mellitus presents with painless, swollen right ankle joint. Radiographs of the ankle show destroyed joint with a large number of loose bodies. The most probable diagnosis is - \nSelect and explain. \nA. Charcot's joint, B. Clutton's joint, C. Osteoarthritis, D. Rheumatoid arthritis", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Painless swollen ankle, destroyed joint and multiple loose bodies in a diabetic patient suggest the diagnosis of Charcot’s joint (neuropathic joint).\nJoint destruction without pain is characteristic of Charcot’s joint.', 'role': 'assistant'}]