FEMORAL BONE RESORPTION OBSERVED IN CANINE THA USING BIOACTIVE BONE CEMENT

Polymethylmethacrylate (PMMA) bone cement, which has been widely used in total hip arthroplasty (THA), has several problems. To improve these problems, the authors have developed new bioactive bone cement, which has a capability of bonding directly with bone, and has greater mechanical strength than PMMA bone cement. In this study, THAs were performed in dogs using bioactive bone cement (BABC) consisting of AW glass-ceramic powder and SiO₂ powder as the filler and bisphenol-a-glycidyl dimethacrylate (Bis-GMA) based resin as the organic matrix, and the outcomes were compared with the results of PMMA bone cement. Previously, we reported on a higher bonding strength and higher Affinity index of BABC to bone in dogs’ femora for up to 24 months. In the present study, femoral bone resorption was observed at 24 months after implantation in the BABC group, although it was not observed in the PMMA bone cement group. Resorption rate of the BABC group calculated by digitizer using SEM images of cross section of the femur was 4.4±4.4 % and 10.1 ± 4.1 % at 12 months and 24 months, respectively, whereas that of PMMA group was 1.3±1.9 % and 1.5±0.7 % at 12 months and 24 months, respectively. There was a significant difference between both groups at 24 months.