BLOOD PERFUSION AND REMODELING ACTIVITY IN CANINE TIBIAL DIAPHYSIS AFTER FILLING WITH A NEW BONE-CEMENT COMPARED TO BONE WAX AND POLY(METHYL METHACRYLATE) CEMENT

Six dogs each had one tibia filled with standard poly(methyl methacryl ate) (PMMA) bone cement and the contralateral tibia filled with a new methyl methacrylate-n-decyl methacrylate-isobornyl methacrylate (MMA-D MA-IBMA) bone cement (Boneloc(R)) with lowered polymerization heat and monomer leakage, An additional six dogs each had one tibia filled wit h MMA-DMA-IBMA and the contralateral tibia filled with bone wax. There was a higher diaphyseal blood flow, measured with a microsphere techn ique, in the legs filled with MMA-DMA-IBMA than in those filled with P MMA. The wax-filled bones presented higher blood perfusion than those with MMA-DMA-IBMA. We found a tendency towards higher (99m)technetium- labelled methylene diphosphonate ((99m)TcMDp) uptake, and autoradiogra ms revealed a tendency towards larger subperiosteal apposition and mor e blackening, both at the subperiosteal apposition and the cortex, in the bones filled with new bone cement in the first series, but in wax- filled bone in the second series. it is concluded that the new bone ce ment, compared to standard acrylic bone cement, seems to inhibit the v ascular response and bone remodelling activity less, making earlier re modelling possible. However, the new bone cement still seems to inhibi t bone blood perfusion compared to bone wax.