低剂量激素诱导股骨头缺血性坏死模型的建立

背景：激素性股骨头缺血性坏死的发病机制尚未明确。 目的：单纯应用低剂量激素作用于新西兰大白兔，建立激素性股骨头缺血性坏死模型并观察造模效果。 方法：将30只新西兰大白兔随机分为2组。实验组每周经臀肌注射4 mg/kg甲泼尼龙琥珀酸钠，对照组于相同时间点注射等量生理盐水。同时迫使动物直立进食、饮水，以增加股骨头的负重。 结果与结论：肌注甲泼尼龙琥珀酸钠后，白兔出现不同程度的精神萎靡、活动减少、体质量减轻等。给药4周后，兔血清总三酰甘油及低密度脂蛋白增高、高密度脂蛋白降低(P < 0.05)；血清碱性磷酸酶及总胆固醇分别在给药6，8周后明显增高 (P < 0.05)。苏木精-伊红染色显示；给药4周后，兔股骨头骨髓腔内脂肪细胞体积增大，数量增多；给药6周后，空骨陷窝率增大；给药8周后，骨小梁稀疏变细、结构紊乱，软骨区可见死骨形成及部分性坏死和软骨面塌陷。说明单纯注射低剂量激素可以复制出典型的激素性股骨头缺血性坏死模型。

Establishment of a femoral head model of low dose steroid-induced osteonecrosis

BACKGROUND: With the widespread use of steroid hormone, the incidence of steroid-induced osteonecrosis remained high, but the pathological mechanism of human femoral head avascular necrosis is unclear. OBJECTIVE: To establish a model of steroid-induced osteonecrosis of femoral head and to discuss the effects of low dose of steroid in New Zealand white rabbits. METHODS: Thirty rabbits were randomly divided into two groups. The experimental group rabbits received intramuscular injection of 4 mg/kg methylprednisolone sodium succinate; the control group rabbits were injected with the same amount of physiological saline at the same time. The venous blood reticulocytes were extracted for serological testing before and at 4, 6 and 8 weeks after exsangquinations. At 4, 6 and 8 weeks after steroid administration, histopathology of femoral head was performed and these rabbits were euthanized in batch. RESULTS AND CONCLUSION: During the experimental process, one rabbit in the experimental group died. A total of 29 rabbits were involved in the analysis of results. During experimental course, the experimental group rabbits exhibited depressed consciousness and reduced activities and decreased weight loss (P < 0.05) after steroid administration. During the 4th week after administration, cells in the marrow cavity expanded and multiplied in number, which could be observed through the use of light microscope, and the percentage of fat cell size was higher compared with the control group (P < 0.05). At the 6th week, bone empty lacunae percentage was increased compared with the control group (P < 0.05). At the 8th week, the bone trabeculae of the experimental group were reduced and disordered, and disconnected, bone trabecular area percentage was decreased compared with the control group (P < 0.05), and there were parts of sequestrum and collapse in the area of cartilage. At the 8th week, total cholesterol level in the experimental group was significantly higher than that in the control group (P < 0.05). At the 4th week, total triglycerides and low density lipoprotein level in the experimental group was significantly higher than that in the control group (P < 0.05); high density lipoprotein level was significantly higher than that in the control group (P < 0 .05). At the 6th week, serum level of alkaline phosphate was significantly increased compared with the control group (P < 0.05). Osteobecrosis of femoral head can be induced by low dose of steroid in rabbits.