自行设计轴向量化加压装置模拟正加速度致兔椎间盘退变模型的建立

Constructing rabbit model of lumbar intervertebral disc degeneration induced by new controlled axial pressure device to accurately simulate positive acceleration load

目的：用自行设计的可控轴向加压装置直接对兔椎间盘加压，建立椎间盘退变模型，模拟高性能战斗机飞行环境中正加速度负荷对腰椎间盘的影响。方法首先测量8只新西兰大白兔（体重2～2.5 kg，雌雄不限）的L4和L5椎标本的高度、中前后径和下前后径，根据测量结果选择穿刺进针点，用自行设计轴向定量可控加压装置直接加压，压力40 N，每次持续15 s，间隔5 min，每日重复10次。24只新西兰大白兔随机分为实验4周组、实验8周组和对照组，MRI观察兔椎间盘退变的情况。结果自行设计的加压装置，在实验中能够很好地准确加压，且压力可调、数值精确可读，动物实验操作简单，经皮穿针、创伤小、易存活；其间动物活动及生长发育并无明显受限，24只动物进入实验，达到要求的19只，成功率为79%。MRI检查初步结果显示，经椎间盘直接加压4周后即可导致兔椎间盘退变，8周后退变更显著。结论用可控加压装置建立动物模型成功率较高，对椎间盘发病节段进行轴向加压量化，可较好模拟飞行环境正加速度变化情景，实验动物模型的可重复性、稳定性、可靠性和经济实用性都较好，可为正加速度导致飞行员腰椎间盘退变进一步研究提供新的实验方法。

ObjectiveWe tried to make use of quantitative control with axial pressure device to establish animal model. We designed and investigated the axial pressure effects of rabbit lumbar intervertebral disc by using the new controlled device to simulate the intervertebral disc degeneration under acceleration load.MethodsFirst, we measured lumbar 4 and lumber 5 vertebral body （height, middle and below anteroposterior diameter） on New Zealand white rabbits’ the lumbar spine specimens, and according to the measurement we located the needle puncture point, designed pressure device which quantitatively repeated the operation. 24 New Zealand white rabbits （2~2.5 kg in weight, male and female randomly） were divided into experimental group lasting 4 weeks, experimental group lasting 8 weeks and control group respectively. The experimental groups were used with the self-designed controllable axial pressure device that punctured through the adjunctive vertebra of corresponding intervertebral discs.ResultsAmong 24 rabbits in the experiment, 19 met the requirements, whose success rate was 79%. After operation, rabbits spent 1 week or so which was called adaption stage, often survived for a long time. According to observation, they could survive up to 5 months, during which their activity and limited growth were not obvious.ConclusionsPressure device is stabile, small and light, can accurately increase pressure in the experiment. Animal experimental operation is simple with percutaneous needle with mini trauma, animals are more likely to survive; controllable pressurizing device experimental animal model can be used for accurate analysis of positive acceleration load of intervertebral disc degeneration in flight environment. The animal models provide a new field for further research of pilots’lumbar degeneration.