强迫体位下谐振对腰部椎间盘组织形态学影响的实验研究

Experimental study:influence of resonance at constrained body posture on histomorphology of intervertebral discs

目的 观察强迫体位下谐振对兔腰椎间盘组织形态学影响,探讨振动引起腰椎间盘病理学改变的机制。方法 取90只成年健康的日本大耳白兔,随机分为正常对照组、造模对照组、4 Hz振动组、5 Hz振动组、6 Hz振动组5组,每组18只。分别于实验第2、4、6周每组随机抽取6只实验动物,取其腰5~6椎间盘组织,观察其组织形态学变化,并进行病理学评分。结果 振动组整体髓核组织形态改变相对较造模对照组出现早,振动6 Hz组椎间盘组织病理学评分明显高于其他组别（P〈0.05）,且随时间延长逐渐升高;振动4 Hz组与造模对照组相比无明显变化。结论 振动产生动态应力易导致髓核组织病变,产生谐振效应时可使椎间盘组织产生的病变程度最大。

Objective To analyze the effect of resonance at constrained body posture on histomorphology of rabbit intervertebral discs,and investigate the mechanism of vibration with different frequencies effecting on the rabbit intervertebral discs. Methods Ninety healthy rabbits were randomly divided into 5 groups （n=18）. Group A as normal group ;Group B as control group; Group C as 4 Hz vibration group ;Group D as 5 Hz vibration group; Group E as 6Hz vibration group. L5/6 intervertebral discs of six rabbits were extractioned at 2,4,8 week in each group randomly. Changes of intervertebral discs in histomorphology were observed in different time points,and pathological grades were recorded. Results Pathological changes of nucleus pulposus in vibration groups were earlier than that in normal and control group,and pathological grade in 6 Hz vibration group was obviously higher than that in other groups, which advanced with time.There were no significant difference between 4 Hz vibration group and control group in pathology of nucleus pulposus. Conclusion Dynamic stress caused by vibration can easily induce the harmful pathological changes of nucleus pulposus,and appearance of resonance effect will lead to a grave destroy.