激素性股骨头缺血性坏死兔模型的构建

Establishment of steriod-induced osteonecrosis models of the femoral head in rabbits

背景:成人股骨头缺血性坏死可导致股骨头塌陷和髋关节破坏,但其真正的病因和发病机制尚未完全明了。因此建立实验性动物模型是目前研究激素性股骨头缺血性坏死的重要手段之一。目的:建立兔激素性股骨头缺血性坏死模型,探讨其可能的发病机制。方法:将健康成年新西兰白兔以抽签法随机分成4组。对照组,注射生理盐水;激素组,注射甲基泼尼松龙3次;单次内毒素组,静脉注射大肠杆菌内毒素24h后,立即注射甲基泼尼松龙3次;双次内毒素组,大肠杆菌内毒素注射24h后重复给药1次,随后注射甲基泼尼松龙3次。造模前及造模后行X射线片、MRI检查及组织学检查、透射电镜观察,并计算空骨陷窝率。结果与结论:造模第8周时激素组、单次内毒素组、双次内毒素组空骨陷窝率较对照组明显增高(P<0.01),并且双次内毒素组空骨陷窝率明显高于激素组和单次内毒素组(P<0.01)。双次内毒素组较激素组及单次内毒素组股骨头出现坏死的时间更早、坏死的效果更显著,并且随着时间的推移股骨头坏死的效果越来越明显。说明在相同的实验条件下,实施双次内毒素与激素联合诱发股骨头坏死出现最早、坏死效果最明显,且骨陷窝空虚率随时间的延长而增加。

BACKGROUND： Avascular necrosis of femoral head can lead to femoral head collapse or hip impairment, but the precise etiological factor and pathogenesis remain poorly understood. Therefore, it is an important mean to study glucocorticoid-induced avascular necrosis of femoral head by establishing animal models. OBJECTIVE： To establish a stable animal model for glucocorticoid-induced avascular necrosis of femoral head in rabbits, and to explore the mechanism of osteonecrosis femoral head. METHODS： Healthy adult New Zealand white rabbits were randomly divided into 4 groups. Control group： intramuscular injection of normal saline. Hormone group： hip muscular injection of methyllprednisolone three times. Single endotoxin group： injection of endotoxin followed by three times injections of methyllprednisolone after 24 hours. Double endotoxin group： twice injection of endotoxin and three times injections of methyllprednisolone. X-ray, MRI imaging, histopathological examination, as well as transmission electron microscope were performed prior to and after operation. The rate of empty lacunae was calculated. RESULTS AND CONCLUSION： The rate of empty lacunae in the hormone, single endotoxin and double endotoxin groups were obviously increased than that of the control group at 8 weeks after model preparation （P0.01）, especially highest in the double endotoxin group （P0.01）. Compared with the hormone and single endotoxin groups, the femoral head osteonecrosis in the double endotoxin group presented earlier and seriously, and the osteonecrosis increased with time prolonged. The findings demonstrated that twice endotoxin injection combined with three times hormone injection induced osteonecrosis of femoral head early and obviously. The rate of the empty lacunae increased with time prolonged.