Repair of segmental bone defects using bioactive bone cement: Comparison with PMMA bone cement

We developed a bioactive bone cement (BABC) that consists of apatite and wo llastonite containing glass ceramic (AW-GC) powder and bisphenol-A-glycidyl dimethacrylate (Bis-GMA) based resin. In the present study, the effectiven ess of the BABC for repair of segmental bone defects under load-bearing con ditions was examined using a rabbit tibia model. Polymethylmethacrylate (PM MA) bone cement was used as a control. A 15-mm length of bone was resected from the middle of the shaft of the tibia, and the tibia was fixed by two K irschner wires. The defects were replaced by cement. Each cement was used i n 12 rabbits; six rabbits were sacrificed at 12 and 25 weeks after surgery, and the tibia containing the bone cement was excised and tension tested. A t both the intervals studied, the failure loads of the BABC were significan tly higher than those of the PMMA cement. The BABC was in direct contact wi th bone, whereas soft tissue was observed between the cement and bone in al l PMMA cement specimens. Results indicated that the BABC was useful as a bo ne substitute under load-bearing conditions. (C) 1999 John Wiley & Sons, In c.