Question:medium
Metal on metal articulation should be avoided in:
Metal on metal articulation should be avoided in:
Show Hint
Think about cobalt and chromium ions crossing the placenta and decades of exposure.
Updated On: Jun 24, 2026
- Osteonecrosis
- Young female
- Inflammatory arthritis
- Revision surgery
Show Solution
The Correct Option is B
Solution and Explanation
The whole worry with a metal on metal hip is the metal it sheds. As the two metal surfaces rub, they liberate cobalt and chromium ions that build up locally and circulate in the blood.
Now ask which patient is hurt most by that. A young woman who may become pregnant is the answer. The ions can reach the placenta and potentially the fetus, and because she is young the implant must last decades, so her lifetime ion load would be high. On top of that, soft tissue reactions to the debris, the pseudotumours and metallosis, are reported more often in women. All of this points to keeping metal on metal away from the young female.
The remaining options do not carry this particular flag. Osteonecrosis is about dead bone and choosing a construct that bypasses it, inflammatory arthritis is about bone quality and fixation, and revision surgery is about bone stock and component compatibility. None of them is driven by the ion and pregnancy concern that defines the answer.
\[\boxed{\text{Young female}}\]
Now ask which patient is hurt most by that. A young woman who may become pregnant is the answer. The ions can reach the placenta and potentially the fetus, and because she is young the implant must last decades, so her lifetime ion load would be high. On top of that, soft tissue reactions to the debris, the pseudotumours and metallosis, are reported more often in women. All of this points to keeping metal on metal away from the young female.
The remaining options do not carry this particular flag. Osteonecrosis is about dead bone and choosing a construct that bypasses it, inflammatory arthritis is about bone quality and fixation, and revision surgery is about bone stock and component compatibility. None of them is driven by the ion and pregnancy concern that defines the answer.
\[\boxed{\text{Young female}}\]
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