椎间失稳致兔腰椎软骨终板退变的形态学研究

目的:研究兔腰椎软骨终板退变中的形态学变化.方法:将24只新西兰白兔随机均分为实验组和对照组,实验组通过切除兔腰椎棘上、棘间韧带,咬除部分关节突关节,分离椎旁肌造成腰椎软骨终板退变模型,分别于术后12、24、36周对腰椎摄X线片,行HE及甲苯胺蓝染色观察软骨终板形态学的变化;并行软骨终板蛋白多糖及胶原检测.结果:X线片示软骨终板随时间的延长而逐渐钙化,且实验组较对照组钙化明显;随软骨终板退变进程,HE染色示实验组软骨终板较对照组明显变薄,潮标明显前移,血管芽周嗣钙化;甲苯胺蓝染色示实验组软骨终板染色逐渐变淡,细胞层数明显变少;蛋白多糖含量及胶原释放量逐渐降低,不同时间段实验组明显较对照组低(P<0.01).结论:椎间失稳可导致软骨终板形态学及细胞外基质变化,造成软骨终板退变,为进一步研究其退变机理提供理论依据.

Morphologic study on lumbar cartilage eadplate degeneration of rabbit due to the intervertebral destabilization

Objective: To study morphological changes on cartilage endplate (CEP) degeneration due to intervertebral destabilization. Mothods: Experimental models of lumbar CEP degeneration in 24 rabbits were established by resecting all of the lumbar supraspinous and interspinous ligaments,the part of the zygapophysial joints,and detaching of the posterior paravertebral muscles from lumbar vertebrae. The lumbar spine was examined by X-ray at 12,24 and 36 weeks after operation,respectively. HE and toluidine blue stain was performed for exploring the morphologic features of CEP. Detection of proteoglycan and collagen were also carried out. Results: X-ray showed that the CEP calcified gradually as operation time went on,with the more serious calcification in experimental group comparing to that of control. HE stain indicated that the layer of CEP became thinner with the development of degeneration,the early tidemark of CEP appeared,and calcification around blood vessel bud proceeded. CEP toluidine blue stain in experimental group faded and cellular layers decreased markedly. The content of proteoglycan and collagen decreased gradually,and was significant lower in experimental group comparing to that in control group (P<0.01). Couclusions: Mechanical instability of the lumbar spine can lead to the changes of morphology and extracellular matrix,and result in the degeneration of CEP. The study provides further basis for the mechanism of degeneration.