克氏针表面涂有辛伐他汀聚乳酸涂层对卵巢切除大鼠股骨骨折愈合的影响

背景：前期研究已经证实口服应用辛伐他汀可以显著提高骨折愈合质量,加快骨折愈合的速度。目的：进一步验证克氏针表面涂有辛伐他汀聚乳酸涂层后对卵巢切除大鼠股骨骨折愈合的影响。方法：3月龄雌性SD大鼠40只,随机分为单纯骨折组、去势骨折组、涂层对照组及涂层治疗组,后3组大鼠行双侧卵巢切除制作骨质疏松模型,4周后所有大鼠行闭合性股骨中段骨折克氏针内固定。涂层对照组所用克氏针表面涂以聚乳酸,涂层治疗组克氏针表面涂以混有辛伐他汀（50μg/支）的聚乳酸,其余两组克氏针表面未经特殊处理。结果与结论：与涂层对照组相比,涂层治疗组在骨折后6周,X射线表现骨折线模糊,骨痂填满骨缺损,骨膜反应较深,X射线评分显著增高（P〈0.05）。组织病理学显示涂层治疗组骨痂内新生骨小梁数量较多,排列致密均匀;免疫组织化学染色骨形态发生蛋白2阳性细胞表达强烈,积分吸光度值显著高于涂层对照组（P〈0.05）,但血管内皮生长因子表达水平在骨折后6周时显著低于涂层对照组和模型组（P〈0.05）。提示混有辛伐他汀的聚乳酸涂层可以促进大鼠骨质疏松性股骨骨折的愈合。

Effects of Kirschner wire with simvastatin polylactic acid coatings on femoral fracture healing in ovariectomized rats

BACKGROUND：Preliminary studies have proved that oral administration of simvastatin can improve the quality and speed of fracture healing.OBJECTIVE：To investigate the effects of Kirschner wire followed simvastatin polylactic acid coatings on femoral fracture healing in ovariectomized rats.METHODS：Forty 12-week-old health female Sprague-Dawley rats were randomly divided into four groups,fracture group,ovariectomized fracture group,polylactide group and simvastatin group.All the rats except those in the fracture group underwent bilateral ovariectomy to prepare the model of osteoporosis.The closed femur fractures of the rats were treated with Kirschner wire internal fixation 4 weeks later.The Kirschner wire in the polylactide group was coated with polylactide,and that in the simvastatin group was polylactide mixed with simvastatin（50 μg/implant）.The Kirschner wires in the other groups were without treatment.RESULTS AND CONCLUSION：Compared with the polylactide group,fracture line in the simvastatin group was less distincted,the periosteal reaction was fiercer,and the score of X-ray analysis was increased significantly（P 0.05）.Histopathological observation showed that new woven bone was more and arranged tightly and regularly in the simvastatin group.Immunohistochemical staining showed strong expression of bone morphogenetic protein-2 positive cells in the simvastatin group and the integrated optical density value was significantly higher than that of the polylactide group（P 0.05）,but the level of vascular endothelial growth factor in the simvastatin group was significantly lower than those of the polylactide group and model group（P 0.05）.The polylactide mixed with simvastatin coatings can promote the healing of osteoporotic hip fracture in ovariectomized rats.