激素联合脂多糖诱导股骨头缺血坏死模型兔的骨质变化

摘要

BACKGROUND:The rabbit model of osteonecrosis of the femoral head (ONFH) has been successfully established by glucocorticoid combined with lipopolysaccharide.OBJECTIVE:To observe the dynamic changes of bone mass in the early steroid-induced ON FH.METHODS:Twenty-four adult New Zealand white rabbits were randomly divided into experimental and control groups (n=12 per group).Rabbits in the experimental group were injected with lipopolysaccharide and glucocorticoid to establish the model of ONFH,while those in the control group given the same volume of normal saline.The changes in the femoral head structure,morphology and distribution of the trabecular bone at 5,1 0,15 and 20 days after modeling were observed through multi-slice spiral CT,micro-CT and hematoxylin-eosin staining;the bone mineral density and rate of empty lacunae were detected.RESULTS AND CONCLUSION:The imaging examinations showed that the rabbit femoral head was intact and smooth in both groups;on days 15 and 20,in the experimental group,the cortical bone became thinner,the trabecular bone became sparse and discontinuous,and the bone mineral density,tissue mineral density and bone volume/total volume were significantly lower than those in the control group (P ＜ 0.01).The histological observation indicated that there were more empty lacunae and adipocytes,as well as less osteocytes and hematopoietic cells in the experimental group;the rate of empty lacunae in the experimental group was significantly higher than that in the control group on days 15 and 20 (P ＜ 0.01).These findings suggest that in the early stage of ONFH,necrotic osteocytes increase in number,accompanied by trabecular micro-fractures,which leads to a decrease in bone mineral density,eventually resulting in bone remodeling disturbance.%背景:前期研究采用激素联合脂多糖己成功构建股骨头缺血坏死兔模型.目的:进一步观察激素性股骨头坏死早期骨质的动态变化.方法:成年新西兰大白兔24只,随机分为实验组(n=12)和对照组(n=1 2).实验组采用激素联合脂多糖改良技术建立激素性股骨头缺血坏死兔模型,对照组相同部位注射等体积生理盐水,饲养条件不变.建模完成后,分别于第5,10,15,20天进行股骨头多层螺旋CT、显微CT及苏木精-伊红染色检测,观察股骨头结构,骨小梁形态、分布,测定骨质密度及空骨陷窝率.结果与结论:①影像学结果显示,实验组与对照组兔股骨头形态完整,关节面光滑,第15,20天实验组股骨头骨皮质变薄,骨小梁分布稀疏,间距增宽,不连续,骨矿物质密度、组织矿物质密度、骨体积分数值均显著低于对照组(P＜0.01);②病理学结果显示,实验组空骨陷窝和脂肪细胞不断增多,骨细胞和造血细胞逐渐减少,第15,20天空骨陷窝百分率显著高于对照组(P＜ 0.01);⑨结果说明,激素性股骨头坏死早期股骨头内骨细胞坏死增多,伴骨小梁微细骨折发生,导致骨质密度减低,最终可造成骨重塑障碍.