Contamination of polyethylene cups with polymethyl methacrylate particles: An experimental study

The articulating surfaces of 6 ultra–high molecular weight polyethylene cups were exposed to curing polymethyl methacrylate (PMMA) bone–cement and examined with scanning electron microscopy and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Three of the cups were exposed to blood and bone–cement, and the rest were exposed to bone–cement only. After removal of the bone–cement bulk, PMMA particles were found and identified in all 6 cups. The particles were verified by identifying zirconium with energy-dispersive x-ray fluorescence spectroscopy in 5 cups and with LA-ICPMS in 1 cup. The degree of surface contamination was estimated with LA-ICPMS. The number of zirconium-containing particles detected was on average 10 to 20/mm². PMMA bone–cement left in polyethylene cups during polymerization can contaminate the articulating surface with adherent PMMA particles.