自体筋膜固定腰椎滑脱的生物力学实验研究

Biomechanical study of the lumbar spondylolisthesis fixed with auto-graft fascia

目的 :评价自体筋膜治疗腰椎滑脱术后及循环载荷下的生物力学特征。方法 :18具新鲜猪脊柱运动节段 (L4 ～L5)标本模型按正常组、滑脱组、筋膜固定组顺序进行试验。先对比观察各组在脊柱三维空间分析系统屈伸活动的水平位移。再用双轴液压伺服生物材料测试系统进行载荷下屈伸试验。获得首次载荷循环及每间隔 2 5 0次 ,共 15 0 0次循环运动范围及初始刚度值 ,进行统计学处理。结果 :滑脱组水平位移大于正常组和固定组 ,差异显著 (P <0 .0 5 )。首次循环载荷下 ,滑脱组活动范围大于正常组和固定组 ,差异非常显著 (P <0 .0 1)。首次循环载荷 ,滑脱组屈、伸初始刚度均小于正常组及固定组 ,差异非常显著 (P <0 .0 1) ,固定组也明显大于正常组 ,两者差异显著 (P <0 .0 1,P <0 .0 5 )。第 15 0 0次循环载荷下的初始刚度仍高于正常组。结论 :采用自体筋膜固定腰椎滑脱术后瞬时失稳和保持其稳定性是有效的 ,为临床应用提供了生物力学依据。

Objective:To evaluate the biomechanical characteristics of the lumbar spondylolisthesis fixed with auto graft fascia.Methods:18 fresh porcine lumbar spine(L 4～L 5) were divided into three groups:normal;spondylolisthesis and fixed with auto graft fascia.Firstly,the parallel movement of each group was observed and compared with the spine three dimensional analysis system.Secondly,they were underwent the experiment of loaded flexion extension with the 858.02 mini bionix test system.The measured results of inital stiffness,the initial loading cycle and the move range during 250 interval of 1500 cycles were statistically analyzed.Results:Parallel movement of spondylolisthesis group was significantly greater than that of normal group and auto graft fascia group ( P <0.05).During the first loading cycle,the initial stiffness of spondylolisthesis group was smaller than that of normal group and auto graft fascia group ( P <0.01).The measured data of auto graft fascia group was greater than that of spondylolisthesis group too (P <0.01 and P < 0.05 ).After 1500 loading cycles,the stiffness of auto graft fascia group was still greater than that of normal group.Conclusion: Effective to stabilize the lumbar spondylolisthesis and maintain its stable during cycle loading,the method of the lumbar spondylolisthesis fixed with auto graft fascia provided biomechanical basis for clinical application.