Highly cross-linked polyethylene (HXLPE) used in modern total hip bearings reduces wear by:
- A Increasing the molecular weight of the polymer chains
- B Creating inter-chain covalent bonds via gamma or electron beam radiation reducing adhesive wear ✓
- C Adding vitamin E to enhance fatigue crack propagation resistance
- D Reducing the contact area between femoral head and acetabular liner
Explanation
High cross-linking of polyethylene is achieved by irradiation (gamma or electron beam at 50–100 kGy), which creates inter-chain covalent bonds (cross-links) that prevent polymer chain pull-out during sliding motion, dramatically reducing adhesive and abrasive wear by up to 90%. The trade-off is reduced fatigue crack resistance (oxidation from free radicals), which is mitigated by remelting or adding vitamin E antioxidant in second-generation HXLPE. Note: option C describes a separate second-generation refinement added after cross-linking, not the primary mechanism of wear reduction.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.