【摘要】 背景:目前的椎间盘退变动物模型主要通过改变椎间盘生物力学环境、损伤椎间盘自身结构以及应用基因技术改变动物的遗传性状等诱发退变,但这些方法均为外界人为因素直接作用于椎间盘,与椎间盘退变的自然病程差别较大。目的:评价经皮穿刺兔腰椎终板下椎体注射平阳霉素制作椎体终板下缺血模型的可行性。方法:选取新西兰大白兔46只,每兔设L5为实验组、L4为对照组。穿刺腰椎终板下椎体,L5注射平阳霉素(2g/L)1mL,,L4注射生理盐水1mL。其中4只兔子术前行腰动脉造影。术后第1,2,3,4,5周,2个月及3个月随机选取6只行MRI检查,并取病理送检。测量对比第4周实验组MRI与病理切片的缺血面积。结果与结论:对照组MRI和病理学检查均无特异性变化,实验组MRI第1,2周变化不明显,第3周出现FST1WI低信号,T2WI及FST2WI呈稍高信号,第4周信号变化更明显;实验组病理第1,2周无特异性变化;第3,4周骨小梁排列杂乱,骨细胞逐渐减少,椎体骨髓内血细胞减少,脂肪细胞增多融合,终板软骨细胞减少、结构紊乱,纤维环及髓核无明显变化;第5周出现椎间盘退变表现;第2,3个月终板下椎体缺血持续存在、椎间盘退变更加明显。实验组第4周MRI与病理切片缺血面积之间有显著正相关性(r=0.965,P<0.001)。结果证实,采用经皮穿刺终板下椎体注射平阳霉素的方法可成功制作兔腰椎终板下缺血动物模型,具有创伤小、操作简便、重复性好和成功率高的特点。该模型是研究腰椎及椎间盘退变较理想的一种动物模型。更多还原

【Abstract】 BACKGROUND:Currently,the widely used intervertebral disc degeneration models are induced by altering intervertebral disc biomechanics,damaging intervertebral disc structure or changing hereditary features with genetic technique. All these methods are varies from natural duration of intervertebral disc degeneration. OBJECTIVE:To evaluate the feasibility of the establishment of rabbit model of ischemic lumbar vertebrae adjacent to endplate by percutaneous puncture followed by pingyangmycin injection. METHODS:A total of 46 New Zealand white rabbits were selected and two vertebraes were divided as experimental group (L5) and control group (L4) in every rabbit. Vertebrae adjacent to endplate was punctured. Pingyangmycin (2 g/L) 1 mL was injected into rabbits in the experimental group. And 1 mL normal sodium was injected into the control group. Lumbar artery angiography was performed in 4 rabbits before operation. Six rabbits were randomly performed MRI and then were executed for vertebral histology at weeks 1,2,3,4,5 and months 2,3 after operation. Ischemic areas of L5 were measured by the MRI and histological section at week 4 after operation. RESULTS AND CONCLUSION:MRI and histology of control group had not specific changes. MRI had not significant signal intensity changes in the first 2 weeks in the experimental group. At week 3 after operation,it demonstrated slightly hyperintense signal on T2-weighted image (T2WI) and fat-suppression T2-weighted image (FS T2WI),while fat-suppression T1-weighted image (FS T1WI) was hypointense signal. The signal changed more obviously at week 4. Histology of experimental group had not specific changes in the first 2 weeks. From weeks 3-4,bone trabecula arranged confusedly and disorderly,with gradually decreased osteocyte and marrow haemocytes,while adipocytes increased and coalesced. Cartilage corpuscle of endplate decreased and architecture became disorder. But the anulus fibrosus and nucleus pulposus had no obviously changes. The intervertebral disk of the experimental group degenerated at week 5,and the ischemia of lumbar vertebrae still existed and intervertebral disk degenerated more obviously at months 2-3 after operation. There was significant positive correlation of ischemic areas of experimental group between MRI and histology at week 4 (r=0.965,P < 0.001). The rabbit model of ischemic lumbar vertebrae adjacent to endplate can be established successfully by percutaneous puncture vertebrae adjacent to endplate followed by pingyangmycin injection. The operation is minimally invasive,simple and reproducible,with high success rate. This is a fairly ideal animal model to study the degeneration of the lumbar spine and intervertebral disc.更多还原