In total knee replacement, which bearing surface combination offers the lowest volumetric wear rate but carries the highest risk of catastrophic fracture?
- A Metal-on-highly cross-linked polyethylene (HXPE)
- B Ceramic-on-ceramic (CoC) ✓
- C Metal-on-conventional polyethylene
- D Ceramic-on-HXPE
Correct answer: B. Ceramic-on-ceramic (CoC)
Explanation
Ceramic-on-ceramic bearings generate the least volumetric wear and are biologically inert, making them ideal for young patients. However, the inherent brittleness of ceramic creates a risk of component fracture, especially with squeaking and edge loading. Metal-on-HXPE has significantly reduced wear over conventional polyethylene but still generates some metal ions. Ceramic-on-HXPE avoids ceramic fracture risk while maintaining low wear.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.