摘要目的 观察激素性股骨头坏死微血管变化及高压氧治疗激素性股骨头坏死的作用机制.方法 健康成年日本大耳白兔48只,按数字表法随机分为模型组(36只)及生理盐水组(12只).模型组每周2次肌肉注射醋酸泼尼松龙10 mg/kg,生理盐水组每周2次肌肉注射生理盐水2 ml/kg,共6周.2组各处死2只行病理检查后,随后按数字表法将模型组随机分高压氧治疗组(17只)及对照组(17只).高压氧治疗组在常规治疗基础上行高压氧治疗,共持续6周,对照组呼吸常压新鲜空气.检测实验后2、4、6、8、10、12周兔血液流变学参数、血管内皮生长因子(VEGF),并观察其组织病理学变化及影像学变化.结果 模型组实验2、4、6周血流变学特性恶化;模型组股骨头微血管内膜断裂、血栓形成,股骨头骨质疏松,光镜下空骨陷窝数增多,脂肪细胞数增多,部分骨小梁断裂,透射电镜股骨头骨细胞体积缩小,核固缩,较多骨细胞已坏死溶解成碎片.高压氧治疗组血流变学特性趋向好转,股骨头软骨下区骨小梁表面的成骨细胞和血管出现大量的VEGF阳性表达细胞,阳性部位主要位于血管内膜;光镜下可发现坏死的骨细胞有修复现象,透射电镜可见新生骨细胞.结论 大剂量激素可造成兔股骨头微血管内膜损伤,可能是兔股骨头坏死的重要原因,高压氧通过促进VEGF等细胞因子的分泌,加速股骨头的再血管化和再骨化进程,促进骨修复,可能是高压氧治疗激素性股骨头坏死的重要理论依据.

abstractsObjective To observe microvascular changes in hormone-induced bone necrosis and also to study the mechanism of hyperbaric oxygen (HBO) in the treatment of femoral head bone necrosis.Methods Forty-eight adult Japanese white rabbits were randomly divided into 2 groups:the experiment group (n =36) and the control group (n =12).The animals in the model group (or the experimental group) were injected with 10mg/kg of prednisone acetate,twice a week for a duration of 6 weeks,while the animals in the control group were injected with 2 ml of normal saline,also twice a week for a duration of 6 weeks.Then,the rabbits in the experimental group were randomly divided into the HBO group (n =17) and the control group (n =17).The HBO group received HBO treatment,for 6 successive weeks,while the control group breathed normal fresh air.At the end of 2,4,6,8,10 and 12 weeks after experiment,blood rheology,vascular endothelial growth factor (VEGF),pathological changes in the tissue involved and radiological imaging changes were observed closely.Results At the end of the 2nd week,4th week and 6th week after experiment,features of hemorheology in the model group deteriorated.The animals of the model group developed endangium,thrombosis,osteoporosis of the femoral head,increased numbers of empty bone lacunae and fat cells,rupture of certain bone trabecula,volume reduction of bone cells of the femoral head and quite a few bone cells were seen to be dead and dissolved into fragments under the electron microscope.In the HBO treatment group,hemorheologic features tended to be better,positive expressions of VEGF could be seen in the osteoblasts on the bone trabecula surface and blood vessels as well,and positive expressions were mainly detected in endangium.Repair of necrostic bone cells to some extent could be seen under the light microscope,and neogenetic bone cells could also be seen under the transmission electron microscope.Conclusions Large dosage of hormone could induce damage to endangium,which might be the main cause of avascular necrosis of the femoral head.HBO could accelerate the processes of vascular regeneration and bone ossification through the expressions of VEGF and other cytokines and promote bone repair,which might provide an important theoretical evidence for the treatment of hormone-induced bone necrosis of femoral head.