In total hip arthroplasty, which bearing combination has the lowest in-vivo wear rate, is associated with 'squeaking' as an adverse event, and is contraindicated in patients with renal failure?
- A Metal-on-crosslinked polyethylene
- B Metal-on-metal (MoM)
- C Ceramic-on-ceramic (CoC) ✓
- D Ceramic-on-polyethylene
Explanation
Ceramic-on-ceramic (alumina or zirconia-toughened alumina) bearings have the lowest in-vivo volumetric wear rate of all bearing combinations and do not release metal ions; hence they are preferred in young, active patients. Their characteristic adverse effect is 'squeaking' (occurring in up to 10%), which may require revision if symptomatic. Although ceramic is inert, it is not specifically contraindicated in renal failure — metal-on-metal bearings are contraindicated in renal failure because cobalt-chromium ions accumulate when renal clearance is impaired. Ceramic-on-ceramic does not cause systemic ion toxicity but note that this question tests the combination of lowest wear and squeaking, which uniquely fits CoC.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
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Written and medically reviewed by the StethoPrep medical team.