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': "Perthe's disease is treated by - \nSelect and explain. \nA. High dose of calcium with steroids, B. Total hip replacement, C. Supervised containment of femoral head in acetabulum, D. Relieving weight bearing", 'role': 'user'}, {'content': 'Answer: C \nExplanation: The head is required to be kept inside the acetabulum while the revascularisation takes place (head containment).\nThis may be achieved by conservative methods (plaster, splint etc) or by operation (containment osteotomy).', 'role': 'assistant'}]