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': 'Metal on Metal articulation should be avoided in - \nSelect and explain. \nA. Osteonecrosis, B. Young female, C. Inflammatory arthritis, D. Revision surgery', 'role': 'user'}, {'content': "Answer: B \nExplanation: Based on the articulating surfaces of the prosthesis, THR may be of the following type:-\n\n\nMetal on poly: One surface is metallic (femoral side) and the other is of polyethene (on the acetabular side).\nMetal on metal: Both articulating surfaces are of metal.\nCeramic on ceramic: Both articulating surfaces are of ceramic.\n\nContraindications to Metal on Metal Bearing surfaces\n(Metal on Metal Total Hip Replacement or Metal on Metal Hip Resurfacing)\n\nPatients with Renal Insufficiency (Chronic Renal failure) (Kidney are chiefly responsible for eliminating metal ions from the blood)\nYoung females of childbearing age (Women who may potentially still have children) (Elevated levels of metal ions have harmful effects on the fetus)\nPatients with metal hypersensitivity\n\nContraindications to (Metal on Metal) Hip Resurfacing (Not contraindications to Metal on metal articulation)\n\nLoss of femoral head (severe bone loss: poor bone stock)\nLarge femoral neck cysts (poor bone stock: found at surgery)\nThe small or bone deficient acetabulum\n\nConditions that require caution: Associated with increased risk of failure\n\nTall thin patients\nFemale patients\nPatients with femoral head cysts > 1 cm (on preoperative radiographs)\nPatients with high body mass index > 35\nRheumatoid arthritis (Inflammatory arthritis) and Osteonecrosis (AVIV)\n\nRheumatoid arthritis (Inflammatory arthritis) and osteonecrosis of the hip/ perthe's disease were earlier considered contraindications/ semi- contraindications for Resurfacing. These have now shown to have successful results.", 'role': 'assistant'}]