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': 'An 8 year old boy with a history of fall from 10 feet height complains of pain in the right ankle. X-ray taken at that time are normal without any fracture line. But after 2 years, he developed a calcaneovalgus deformity. The diagnosis is - \nSelect and explain. \nA. Undiagnosed malunited fracture, B. Avascular nercrosis talus, C. Tibial epiphyseal injury, D. Ligamentous injury of ankle joint', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Child is presenting with pain after the injury with :-\n\n\nNormal X-ray → X-rays are normal in physeal injury.\nCalcaneo-valgus deformity → Angular deformity due to physeal arrest.\n\n\nSo, this child had developed physeal injury at the time of trauma.\n\nAbout other options\n\nAny fracture will be seen on x-ray (x-ray is normal in question).\nAvascular necrosis of talus develops after fracture of neck of the talus. X-ray shows the fracture (x-ray is not normal).\nAnkle ligament injury has normal X-ray, but it will not develop angular deformity.', 'role': 'assistant'}]