置入内固定装置轻度持续性牵张对兔脊髓的潜在损伤

Potential spinal cord injury induced by mild persistent stretch of internal fixation

背景:文献报道对脊髓进行不同程度的一过性牵张能造成脊髓不同程度的损伤,但牵张持续性存在时,对脊髓组织造成的影响尚不清楚。目的:安装内固定对兔脊髓进行轻度持续性牵张,观察其对兔脊髓过氧化物歧化酶活性和丙二醛改变的影响。方法:36只健康大白兔随机分为3组:假手术组:仅安装内固定不进行撑开;实验组:牵张动物L1/L2节段达本节段小关节突关节面横径的25%并安装内固定维持牵张;对照组:仅给予同等条件饲养;干预后3,7,14d评价运动功能,并对丙二醛、过氧化物歧化酶做定量分析、组织形态观察脊髓损伤情况。结果与结论:36只大耳白兔均进入结果分析。实验组及假手术组干预后运动功能有少许下降;在7d时运动功能可见恢复,14d时恢复至干预前水平,两组动物运动功能下降程度在同时段组间比较差异无显著性意义;干预后8d开始,各组动物运动功能与干预前无明显差异。脊髓组织中过氧化物歧化酶活力下降而丙二醛含量增加;实验组在3d时可见神经元间隙稍增大,尼氏小体减少,偶见神经元萎缩,无明显其他病理改变。其余两组病理切片未见异常。

BACKGROUND：Reports demonstrated that a transient stretch can cause different degree of spinal cord injury.The effect of persistent stretch on myeloid tissues remains unclear.OBJECTIVE：To observe the effect of mild persistent stretch on expression of superoxide dismutase （SOD） and malonaldehyde （MDA） of rabbits.METHODS：Totally 36 healthy,white,rabbits were randomly divided into 3 groups：rabbits in the sham-operated group only install internal fixation;those in the experimental group were stretched 25% of transverse diameter of L1/L2 articular surface and fixed by internal fixation;those in the control group were housed at the same conditions.At 3,7 and 14 days after intervention,function of spinal cord was assessed,levels of MDA and SOD in spinal cord tissues were determined.RESULTS AND CONCLUSION：A total of 36 rabbits were included in the final analysis.The motor functions of rabbits were slightly decreased in the experimental and sham-surgery groups after operation,which began recovery at 7 days and return to normal levels at 14 days after operation.There was no significance between two groups in decline of motion function at the same time period.From 8 days after operation,the motion function of animals had no significant difference compared with before operation.The SOD activity decreased but MDA contents increased in spinal cord tissues.The neuronal interspaces increased at 3 days,Nissl＇s body reduce,and some neuronatrophy,no other pathological changes could be found in the experimental group.No abnormality could be seen in the other groups.