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
[{'content': "What is Kienbock's disease? \nSelect and explain. \nA. Osteochondritis of lunate, B. Osteochondritis of neck of femur, C. Osteochondritis of navicular, D. Osteochondritis of tibial condyle", 'role': 'user'}, {'content': "Answer: A \nExplanation: Kienbock's disease is an isolated disorder of lunate resulting from vascular compromise to the lunate bone. Fractures of lunate are usually undiagnosed unless they progress to osteochondrosis and become symptomatic and diagnosed as Kienbock's disease. This diagnosis should be considered in any patients between 20 and 40 years presenting with wrist pain and stiffness of insidious onset usually following trauma. On examination there is tenderness dorsally over the lunate and the synol swelling is due to localized synovitis. The radiographic hallmark of Kienbock's disease is increased density of lunate. Ref: Textbook of Ohopaedics and Trauma 2nd edn, By GS Kulkarni page 2476.", 'role': 'assistant'}]