METHYL-METHACRYLATE LEVELS IN UNWASHED SALVAGE BLOOD FOLLOWING UNILATERAL TOTAL KNEE ARTHROPLASTY

To evaluate the safety of autologous reinfusion of drain blood in tota l knee arthroplasty (TKA), eight patients were prospectively evaluated to quantify levels of methyl methacrylate (MMA) monomer in systemic b lood, and in their drain blood after unilateral cemented TKA. The syst emic blood was analyzed before and after reinfusion of the drain blood . The drain blood was analyzed before reinfusion, and both before and after filtration through a 40-mu m filter. A separate study was perfor med on 10 patients to assess the effect of blood, time, and filtration on MMR levels. Levels of MMA monomer in salvage blood were low enough to allow safe reinfusion. Systemic blood showed no evidence of MMA mo nomer either before reinfusion of salvage blood or at 5 minutes after reinfusion. Elimination of MMA is dependent on the time that MMA is ex posed to blood and is independent of filtration.