Objective To establish a reliable unstable pelvic fracture model with sacral plexus stretch injury in goats and to detect electrophysiological signals when pelvis is shifted in different orientations and distance.Methods Twenty-four goats were divided into three groups of 8 animals each:pelvic longitudinal displacement was induced in group A,pelvic lateral displacement in group B,and pelvic dorsal displacement in group C.Animal left L6 and S1 nerve root and initial segment of sciatic nerve were exposed to connect stimulating and receiving electrodes respectively.Left pelvis was shifted at the speed of 0.25 mm/s to produce the model of unstable pelvic fracture with sacral plexus stretch injury.Electrophysiological signals of L6 and S1 were recorded when the placement of pelvis was 0,0.5 and 1.0 cm respectively.Results With pelvic displacement,the threshold potential,maximum stimulus potential and incubation period were gradually increased,but the peak-to-peak value became smaller gradually.When the pelvis displaced 0.5 cm at different orientations,group A showed improved threshold potential and incubation period (P ＜0.05),decreased peak-to-peak value (P ＜0.05),and no significant change in maximum stimulus potential(P ＞0.05);group B only showed lowered peak-to-peak value with no significant variations in other electrophysiological signals (P ＜ 0.05);group C had no significant variations in all electrophysiological signals (P ＞ 0.05).When the pelvis displaced 1.0 cm at different orientations,groups A and B showed improved threshold potential,maximum stimulus potential and incubation period (P ＜ 0.05) and lowered peak to peak value (P ＜ 0.05);group C showed higher incubation period with no significant variations in other electrophysiological signals(P ＜0.05).Between groups,the amplitude of variation in electrophysiological signals was the most in group A and the least in group C.Conclusion After unstable pelvis fracture in goats,sacral plexus stretch injury is the most serious in longitudinal displacement of the pelvis.%目的 建立不稳定骨盆骨折致骶丛神经牵拉损伤动物模型,并利用神经电生理技术,判断骶丛神经在骨盆不同移位方向及距离时的损伤程度,探讨移位方向和距离与骶丛神经损伤的关系. 方法 选择山羊24只,按随机数字表法分为三组:A组(骨盆纵向移位)、B组(骨盆侧方移位)、C组(骨盆背侧移位),每组8只;另正常组为骨盆移位前的所有山羊数.暴露山羊左侧L6、S1神经根及坐骨神经起始段,分别与引导电极和刺激电极连接,以1圈/s(1圈=0.25 mm)速度牵拉骨盆,建立不稳定骨盆骨折致骶丛神经牵拉损伤模型.当骨盆移位距离分别为0,0.5,1.0 cm时,记录山羊L6、S1神经的阈电位、最大刺激电位、峰峰值和潜伏期. 结果 随着骨盆牵拉距离的增大,三组神经阈电位、最大刺激电位、潜伏期均呈逐渐增加趋势,而峰峰值均呈逐渐降低趋势.骨盆不同方向移位0.5 cm时,A组神经阈电位、潜伏期均明显高于正常组(P＜0.05),峰峰值明显低于正常组(P＜0.05),最大刺激电位较正常组差异无统计学意义;B组除峰峰值明显低于正常组(P＜0.05)外,其余电生理信号均发生改变,但与正常组比较差异无统计学意义;C组所有电生理信号变化均不明显.骨盆不同方向移位1.0 cm时,A、B组神经阈电位、最大刺激电位、潜伏期均明显高于正常组(P＜0.05),而峰峰值均明显低于正常组(P＜0.05);C组除潜伏期明显高于正常组(P＜0.05)外,其余电生理信号均不同程度发生改变,但较正常组差异均无统计学意义.三组电生理信号变化幅度比较,A组最明显,B组次之,C组最小. 结论山羊不稳定骨盆骨折致骶丛神经牵拉损伤后,骨盆纵向移位时,骶丛神经牵拉损伤程度最严重.
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