| Objective: Through the Study of microstructure,physical and chemical properties,And the effect of osteogenic capability, degradation and other biological activity used injectable Osteoset-DBM/PMMA and porogen composite bone cement in vertebroplasty. Explore the feasibility of vertebroplasty,and to provide the theoretical basis in further study and clinical applicationMethods: Sodium bicarbonate, BMP-2 containing demineralized bone matrix powder and PMMA bone cement at different mass ratio (1:40:60,0:40:60,1:0 : 100,) mixed form A / B / C three kinds of composite materials, to B, C as control group. 6 healthy adult dogs were randomly divided into three groups in order to1,3,6months,every groups have two dogs. Each selection three lumbars, Preparation lumbar vertebrae defect models by the side back operation. The composite materials A, B, C were inject into the bone defect, The material B,C as control. After operation 1,3,6 month take the specimens for histopathological and scanning electron microscopy, observed Materials of each group at each time of degradation and the new bone growth.Results:1. The Cohesion time of A, B, C three bone cements was 6.19±0.03 min,6.10±0.04 min,4.50±1.03 min; Initial setting time was 14.50±0.20 min,14.46±0.20 min,8.30±0.03 min;Final setting time was 24.03±0.08 min,22.83±0.05 min,15.81±0.03 min. The maximum polymerization temperature of three materials was 51.60±0.25℃,51.60±0.25℃,65.56±0.41℃. The compressive strength of molding materials was 80.6±1.15 MPa,89.7±0.85 MPa,278.4±1.2 MPa. The results of each group resPectively(P<0.05)。2. Three materials are well anti-scattered, The ultrastructural of scanning electron microscopy showed : The group of materials A structure is more loose, more pores, larger pore size, Material B is compact structure, lower porosity and smaller pore size, Material C is more compact structure, porosity is minimal.3.Six dogs of 18 vertebral defect model successfully 17, three kinds of filling materials distributed in the vertebral body, a total of 2 vertebrae in a leak.4. General observation: the procedure compared with the preoperative vertebral body showed no significant deformation, The materials are combined with the bone tissue close, over time, the boundary of materials A,B gradually blurred , the junction seems to be new bone growth, degradation was evident. the boundary of Material C is clear, fibrous tissue wrapped around the material, no new bone growth in boundary.5. Postoperative X-ray: after operation 1 month the ring radiolucent line were seen in the edge of materials A and B, disappeared after 3 month,Over time, materials A,B gradually become smaller, the edge blur. But the ring radiolucent line were seen in the edge of materials C after operation 3 months ,after 6 months the line is more clearly ,the boundary of material has always been clear, no significant change in size.6.Histological and scanning electron microscopy showed: the structure of mateiral A is loosen, more porous, which is degraded and absorbed, in which bone tissue is embedded, find more cellular components,and have a good osteogenic ability; Material B have a certain biodegradable and osteoinductive capacit, However, the degradation rate is slow, and weak osteogenic; the structure of material C is compact, degradation very weak, almost no osteoinductive capacity.Conclusion: The composite material has good physical and chemical properties, as the PVP technique can meet the basic conditions of filling materials, and have good pore structure, Animal tests confirmed that the composite materials have better biocompatibility, biodegradability, bone conduction and bone-induced and other biological properties, The material can be used as filling material used in clinical...
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