纤维环穿刺法诱导兔椎间盘退变模型的组织学和影像学分析

目的探讨纤维环穿刺法诱导椎间盘退变模型的可行性和科学性。方法新西兰大白兔18只,经右侧腹膜外入路用弯血管钳夹持16G穿刺针准确刺入L3-4、L4-5、L5-6椎间盘的纤维环,深度控制在5 mm。于术前及术后4、8、12周对造模后的椎间盘及对照组的椎间盘（以L1-2、L2-3、L6-7为对照）行计算机X线摄影（computed radiography,CR）、MRI检查,并进行组织学观察。结果从手术后第4～12周,造模后的椎间盘高度指数（disc height index,DHI）呈递减趋势,MRI T2WI信号呈现持续减弱趋势（P〈0.01）;组织学观察发现4、8周造模组髓核细胞逐渐减少,12周组髓核细胞几乎被纤维软骨组织替代,纤维环排列不整齐,与髓核界限不清。结论纤维环穿刺法可以诱导兔椎间盘的缓慢退变,为临床深入研究椎间盘的退行性变提供了切实可行的动物模型。

The histological and imaging analyses of rabbit model of degenerative intervertebral disc induced by annulus needle puncture

Objective To investigate the feasibility and scientificalness of establishing an animal model of intervertebral disc degeneration induced by needle puncture in the anulus fibrosus.Methods 18 New Zealand white rabbits under anesthesia underwent puncture of the L3-4,L4-5 and L5-6 lumbar intervertebral discs by 16-gauge needle at a depth of about 5 mm in the right anterolateral anulus fibrosus.Computed radiography（CR）,magnetic resonance imaging scans（MRI）,and histological observations of the discs in both the experimental groups and control groups（L1-2,L2-3,L6-7） were conducted preoperatively and at postoperative 4th,8th,12th weeks,respectively.Result From the postoperative 4th week to 12th week,disc height index（DHI） of CR and T2WI of MRI exhibited a progressive decrease of signal intensity（P0.01）.Histological analyses revealed progressive decrease of nucleus pulposus cells（P0.01）.In the postoperative 12th week group,nucleus pulposus cells were nearly replaced by fibrous cartilage tissue.Annular arrangement became irregular with ill-defined margin from the nucleus pulposus.Conclusion The anulus needle puncture can induce the progressive degeneration of the intervertebral disc in rabbits.This model is available for the clinical study of degenerative diseases of the intervertebral discs.