激素性股骨头坏死发病机制的实验研究

目的 :探讨激素所致股骨头坏死的发病机理。方法 :健康成年中国白兔 36只 ,随机分成两组 ,实验组 2 4只 ,每周 2次肌注地塞米松磷酸钠 7.5mg·kg-1诱发股骨头坏死模型。检测血清总胆固醇、甘油三酯 ,研究病程中脂肪代谢变化规律。对股骨头标本行HE及脂肪染色 ,光镜观察 ,研究股骨头坏死情况。结果 :从第 2周始实验组血清总胆固醇及甘油三酯就显著高于对照组 (P <0 .0 1)。HE染色 :髓腔内脂肪细胞增生 ,骨小梁变细 ,骨细胞核固缩、靠边、深染 ,骨陷窝空虚增多。脂肪染色 :骨细胞内可见脂滴 ,髓腔血管内可见脂肪栓子。且骨陷窝空虚率随用药时间的延长而增加。结论 :激素性股骨头坏死的发病主要与脂肪代谢紊乱有关。

Experimental Study on Pathogenesis of Steroid-induced Osteonecrosis of the Femoral Head

Objective: To study the pathogenesis of steroid-induced osteonecrosis of the femoral head. Methods: Thirty-six adult rabbits were divided into two groups; 24 in experimental group. The animal model of ANFH was established by intramuscular injection of sodium phosphate dexamethasone at a dose of 7.5mg/kg in rabbits two times a week.The law of the lipometabolism was studied by measuring the serum cholesterol and triglyceride during ANFH. The specimens of femoral heads stained with hematoxylin and eosin(HE)and fat-stained with Sudan observing necrosis of the femoral head was studied by light microscopy. Results: The serum cholesterol and triglyceride levels had increased obviously in experimenal group as compared with control group since 2 weeks( P <0.01). Light microscopy showed that the trabecular bone became thin and the nucleus of osteocytes was compressed to one side of the lacuna along with nucleus pyknosis and deep-staining. The empty lacuna and the fatty cells increased in the medullary cavity of the femoral head all at once. Simultaneously fat embous and lipid droplets appeared individually in the vessels and the oseocytes.The rate of the empty lacuna increased with the time of experiment. Conclusion: The disturbed lipid metabolism might be main reason for the mechanism of the steroid-induced ANFH.