Highly crosslinked polyethylene liners used in modern total hip arthroplasty differ from conventional gamma-sterilised UHMWPE primarily because they undergo:
- A Higher irradiation dose followed by post-irradiation melting or annealing to quench free radicals ✓
- B Chemical crosslinking with formaldehyde instead of radiation
- C Ethylene oxide sterilisation at room temperature
- D Addition of carbon fibre reinforcement before moulding
Correct answer: A. Higher irradiation dose followed by post-irradiation melting or annealing to quench free radicals
Explanation
Highly crosslinked polyethylene is produced by irradiating UHMWPE to doses roughly 50 to 100 kGy, several times the 25 to 40 kGy used for terminal sterilisation of conventional polyethylene. Crosslinks dramatically reduce wear. Because irradiation leaves residual free radicals prone to oxidation, the material is subsequently melted or annealed above its melting point to quench them. Chemical crosslinking agents, ethylene oxide, and carbon fibre reinforcement are not part of standard first-generation XLPE manufacture.
Reference: Campbell's Operative Orthopaedics, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.