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': 'Treatment of choice for old non-united fracture of shaft of femur - \nSelect and explain. \nA. Compression plating, B. Bone grafting, C. Nailing, D. Compression plating with bone grafting', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Treatment options for femoral shaft non-union are : -\n\n\nIntramedullar interlock nailing with bone grafting (preferred).\nK-nail with bone grafting.\nPlating with bone grafting.', 'role': 'assistant'}]