Highly cross-linked polyethylene liners are manufactured by irradiating conventional UHMWPE to create cross-links. Which measure addresses the principal drawback created by this irradiation while preserving the wear reduction?

• A Sterilising with ethylene oxide gas after cross-linking
• B Adding barium sulphate filler to improve radiographic visibility
• C Increasing the irradiation dose above 200 kilograys to consume all free radicals
• D Blending the polymer with vitamin E to quench residual free radicals instead of relying solely on post-irradiation melting ✓

Explanation

Gamma irradiation generates free radicals within polyethylene that cause long-term oxidative embrittlement. Post-irradiation melting removes radicals but sacrifices crystallinity and fatigue strength. Vitamin E acts as an antioxidant that stabilises residual radicals, allowing oxidative resistance with better retention of mechanical properties. Simply raising the radiation dose increases cross-linking but also radical burden, so it worsens rather than solves the oxidation problem.

Reference: Campbell's Operative Orthopaedics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.