经伤椎单节段与跨伤椎短节段固定治疗Denis B型胸腰椎爆裂骨折的生物力学实验研究

发布时间：2019-04-18 06:21

【摘要】：目的：胸腰椎爆裂骨折在临床工作中较为常见。临床上多采取手术治疗，但对于术式的选择争议较大。本研究通过进行体外胸腰椎爆裂骨折动物模型生物力学实验，测量经伤椎单节段固定（简称单节段固定）组与短节段固定组（简称短节段固定）在自动控制电子万能试验机上模拟前屈、后伸垂直应力下手术及邻近节段载荷-应变变化，对比两种固定方式的生物力学特性。用生物电测方法评价两种固定方式对胸腰椎生物力学特性的影响，为临床应用提供理论依据和实验指导。材料与方法：8具小牛的新鲜T11-L3脊柱标本，排除骨病与畸形。将标本包埋、固定后在自动控制电子万能试验机上，分别以0.1in/min的载荷增加速度对标本施加150N的前屈、后伸载荷，通过电阻应变仪测出相关测点的应变值。随后将标本采用预损伤后压缩或撞击的方法制作L1椎体爆裂骨折模型，破坏上终板，保留下终板完整。将8具标本随机分为经伤椎单节段固定组，跨伤椎短节段固定组。并采用同样方法测量各测点应变值。分析手术节段及邻近节段的载荷-应变变化。数据的分析使用的是SPSS16.0软件包（SPSS，Chicago，IL，，USA），各组间数据的比较采用单因素方差分析法和scheffe法，配对t检验，P0.05为差异有显著意义。结果：1.两种固定方式均可以获得满意的固定强度，足够维持椎体的稳定性。 2.与短节段固定相比单节段固定同等撑开高度的钉棒承受的应力更小，能更好的恢复椎体的高度，且钉棒疲劳断裂的发生率更低。 3.单节段组与短节段组均存在一定的应力遮挡，但本次未能比较出哪种固定方式应力遮挡效应更明显。结论：经伤椎单节段固定与跨伤椎短节段固定均能获得满意的固定强度，足够维持椎体的稳定性。针对特定的Denis B型爆裂骨折，单节段固定是一种良好的选择。
[Abstract]:Objective: thoracolumbar burst fracture is more common in clinical work. Surgical treatment is more common in clinical practice, but the choice of surgical procedure is controversial. In this study, the biomechanical experiment of the animal model of thoracolumbar burst fracture in vitro was carried out. The changes of the load-strain of the adjacent segments of the injured vertebrae under vertical stress were measured by simulating flexion and postextension in the single segment fixation (single segment fixation) group and the short segment fixation group (short segment fixation) in the automatic control electronic universal tester, and the changes of the load-strain of the adjacent segments were measured under the vertical stress of the injured vertebrae. The biomechanical properties of the two fixation methods were compared. The effects of two fixation methods on biomechanical properties of thoracolumbar spine were evaluated by bioelectric measurement, which provided theoretical basis and experimental guidance for clinical application. Materials and methods: 8 fresh T11-L3 spine specimens of calf were used to exclude bone disease and deformity. The specimens were embedded and fixed on the automatic control electronic universal testing machine. The specimens were subjected to 150 N forward flexion and extension loads at the increasing speed of 0.1in/min load respectively. The strain values of the relevant measurement points were measured by the resistance strain gauge. The fracture model of L1 vertebral body was made by compression or impact after pre-injury. The upper endplate was destroyed and the lower endplate was intact. Eight specimens were randomly divided into single segment fixation group and transtraumatic short segment fixation group. The strain values of each measuring point are measured by the same method. The load-strain variation of the operative segment and adjacent segment was analyzed. SPSS16.0 software package (SPSS,Chicago,IL,USA) was used to analyze the data. One-way ANOVA method and scheffe method were used to compare the data among each group. Pairing t-test showed that there was significant difference between the two groups (P0.05). Results: 1. Both fixation methods can obtain satisfactory fixation strength, enough to maintain the stability of the vertebral body. 2. Compared with the short segment fixation, the stress of the screw rod with the same opening height as that of the single segment fixation is lower, the height of the vertebral body can be recovered better, and the incidence of fatigue fracture of the screw rod is lower than that of the short segment fixation. 3. The single segment group and the short segment group both have certain stress shielding, but this time it is unable to compare which fixed mode stress shielding effect is more obvious. Conclusion: both single segment fixation and short segment fixation of injured vertebrae can obtain satisfactory fixation intensity and maintain the stability of vertebral body. Single segment fixation is a good choice for specific Denis B type burst fractures.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R687.3

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