磷酸三钙填充骨缺损后骨形态发生蛋白2和血管内皮生长因子的变化

背景：目前治疗骨缺损以植骨为主，其中磷酸三钙是目前广泛使用的人工骨材料，但对于磷酸三钙的植骨效果仍有争议，其治疗骨缺损的机制尚无详细报道。 目的：观察磷酸三钙植骨填充于骨缺损区后，局部骨形态发生蛋白2和血管内皮生长因子的浓度变化及骨愈合情况。 方法：取C57小鼠48只，随机均分为实验组与对照组，切除右侧股骨干中部2 mm长的骨干和骨膜制作单侧股骨缺损模型，实验组于骨缺损处植入磷酸三钙，对照组不植入任何物质。术后1-4周拍摄X射线片观察骨愈合情况，随后处死动物，植骨区取材，通过Elisa法测定样本中骨形态发生蛋白2、血管内皮生长因子的水平。 结果与结论：X射线显示，实验组术后2周时骨折大部分愈合，小部分骨皮质未完全愈合，3周时骨折基本愈合，仍有少量磷酸三钙残留，4周时骨折完全愈合，周围骨痂生长明显，磷酸三钙基本吸收；对照组术后一二周时仍可见骨折线，第3周时可见骨折线模糊，第4周时骨折部分愈合，部分骨皮质未愈合。实验组不同时间点骨形态发生蛋白2、血管内皮生长因子水平均高于对照组（P＜0.05）。结果表明磷酸三钙植骨治疗可通过上调骨形态发生蛋白2和血管内皮生长因子的表达，促进骨愈合。

Variation of bone morphogenetic protein-2 and vascular endothelial growth factor after bone defect filled with tricalcium phosphate

BACKGROUND：Currently, bone graft is mainly used for repair of bone defects, and tricalcium phosphate is the most used artificial bone material. But the effectiveness of the tricalcium phosphate bone graft is stil controversial, and there is also no detailed report about its function during the healing of bone defect. OBJECTIVE：To observe the concentration changes of bone morphogenetic protein-2 and vascular endothelial growth factor as wel as bone healing after tricalcium phosphate graft in bone defects. METHODS：Forty-eight C57 mice were randomly divided to experimental group and control group. A 2-mm-long diaphyseal segment and periosteum from the middle of the right femur was cut to prepare unilateral bone defect models. Tricalcium phosphate bone graft was used in the experimental group, and no bone graft in the control group. During the fol owing 4 weeks, X-ray examination was done once a week to observe the bone healing, and then the animals were executed for col ecting samples in the graft area. The concentrations of bone morphogenetic protein-2 and vascular endothelial growth factor in samples which were taken from the bone graft area were determined by using ELISA assay. RESULTS AND CONCLUSION：X-ray films showed that 2 weeks later, bone fracture healed mostly in the＆amp;nbsp;experimental group except a smal part of cortical bone;3 weeks later, bone fracture was basical y healed, and only a smal amount of tricalcium phosphate remained;4 weeks later, bone fracture was completely healed, and the cal us grew obviously, and the tricalcium phosphate was nearly absorbed. In the control group, the fracture line was stil visible at 1-2 weeks, but it became vague at 3 weeks;then, the fracture was healed at 4 weeks except some of the cortical bone. The levels of bone morphogenetic protein-2 and vascular endothelial growth factor were significantly higher in the experimental group than in the control group at different time points （P〈0.05）. These results suggest that tricalcium phosphate bone graft