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': 'Triple deformity of knee is classically seen in -a) Fracture patellab) Tuberculosisc) Rheumatic arthritisd) Rheumatoid arthritis \nSelect and explain. \nA. c, B. d, C. ab, D. bd', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Triple deformity of knee refers to : -\n\n\nFlexion of knee\nExternal rotation of tibia\nPosterior subluxation of tibia\n\n\nTriple deformity is seen in RA, TB of knee and Polio.', 'role': 'assistant'}]