退变性腰椎侧凸发病机制中腰椎小关节生物力学的作用研究

发布时间：2018-04-02 22:12

本文选题：退变性腰椎侧凸　切入点：关节突关节　出处：《第二军医大学》2015年硕士论文

【摘要】：目的：通过影像学资料研究退变性腰椎侧凸中关节突角度、关节突不对称、脊柱-骨盆序列与椎体旋转之间的关系。然后,基于正常并且得到验证的腰椎三维有限元模型建立个体化的退变性腰椎侧凸有限元模型,对其进行力学分析并探讨腰椎关节突关节在退变性腰椎侧凸发病过程中相关的生物力学机制研究。通过研究退变性腰椎侧凸有限元模型中腰椎关节突关节的生物力学特性,为探讨退变性腰椎侧凸形成的相关生物力学机制及其演变过程提供思路,从而指导临床工作。方法：选取60名具有站立位的全脊柱正侧位片以及CT图像的退变性腰椎侧凸患者为研究对象。在正侧位片上测量患者的Cobb角,骨盆入射角(pelvic incidence, PI)和腰椎前凸角(lumbar lordosis, LL)。通过CT横断面测量L3/4,L4/5和L5/S1双侧关节突角度。关节突不对称定义为左、右侧关节突角度相差大于10°。然后,为了建立个体化的退变性腰椎侧凸三维有限元模型并研究其关节突关节的生物力学作用,我们首先将腰椎连续薄层CT平扫获取得DICOM格式的数据导入建模软件,建立腰椎正常三维有限元模型。我们基于临床病人影像学资料将经过验证的正常腰椎模型演变成三种不同弯曲程度的退变性腰椎侧凸有限元模型(Cobb角10°-20°、20-30°、大于30°)。利用专业有限元软件分析L1-L5双侧各个关节突关节相应的受力情况。于L1椎体上施加400N的轴向载荷或是400N载荷结合5 N.m、10N.m以及15N.m的力矩。计算各个椎体双侧小关节受力特点。比较分析三个模型相应关节突关节的应力分布以及接触应力。观察在退变性腰椎侧凸演变过程中关节突关节的作用机制。结果：在Ⅰ型组和Ⅱ型组中,关节突不对称发生率在L3/4(P=0.011), L4/5(P=0.043)以及L5/S1(P=0.004)存在明显差异性。Ⅱ型退变性腰椎侧凸LL值明显小于Ⅰ型退变性腰椎侧凸LL值(P=0.049)。而关节突角度、PI、LL在两组中没有统计学差异性。在两组中,PI与LL均与相关性。通过有限元模型研究发现在退变性腰椎侧凸中,关节突关节受力的改变除了与腰椎的运动情况相关外,还与弯曲的严重程度密切相关。退变性腰椎侧凸发生以后,关节突关节存在压缩、变性以及内聚等改变,导致椎体更易发现旋转脱位以及侧方移位。当侧弯的腰椎进行侧弯运动时,轻度弯曲的侧凸腰椎中,凸侧关节突应力值均大于凹侧关节突；而在中、重度弯曲的侧凸腰椎中,凹侧关节突关节受力明显大于凸侧。当进行旋转运动时,凸侧关节突关节受到的张力明显增大,而凹侧关节突关节受到的压缩力明显减小。结论：在退变性腰椎侧凸中,关节突不对称是引起椎体旋转的重要因素。并且,退变性腰椎侧凸随着LL的减小或消失出现相应的神经症状。退变性腰椎侧凸使得关节突关节承载负荷不均匀。轻度弯曲时,凸侧关节突关节所受负荷较大；中度和重度弯曲时,凹侧关节突关节所受负荷较大。在退变性腰椎侧凸中,腰椎应力线偏向凸侧,凹侧椎体通过压缩变形调节腰椎的平衡,凸侧关节突关节间隙增大导致腰椎不稳,关节突关节失去了维持椎体旋转和侧移的限制作用,椎体在腰椎承受负荷以后更容易向凸侧旋转半脱位且侧向移位。关节突关节不平衡的受力引起腰椎出现力学失衡,最终导致退变性腰椎侧凸发生、发展。
[Abstract]:Objective: To study the degree of joint angle of lumbar degenerative scoliosis by radiographs, facet asymmetry, spine pelvis sequence and vertebral rotation relation between. Then, the normal and degenerative lumbar lateral convex finite element model of individual three-dimensional finite element model of lumbar verification based on mechanical analysis on the biomechanical mechanism and research relevant in the pathogenesis of degenerative lumbar scoliosis of lumbar facet joints. The biomechanical properties of the finite element model of degenerative lumbar scoliosis of lumbar facet joint, to provide ideas for the study and evolution of biomechanical mechanism of lumbar degenerative scoliosis, so as to guide the clinical work. Methods: We selected 60 patients with standing full spine position radiographs and CT images of lumbar degenerative scoliosis patients as the research object. In the radiograph measurement The amount of patients with Cobb angle and pelvic incidence (pelvic incidence, PI) and lumbar lordosis (lumbar lordosis, LL). The CT L4/5 and L5/S1 L3/4 cross section measurement, bilateral facet angle. The facet asymmetry is defined as the left and right side facet angle difference greater than 10 degrees. Then, in order to three-dimensional finite element biomechanical effect the model of degenerative lumbar scoliosis and to study the establishment of individualized facet, we will first continuous lumbar CT scan to obtain software modeling data into DICOM format, the establishment of a three-dimensional finite element model of normal lumbar. Based on clinical and imaging data of our patients after normal lumbar model validation into three different bending degree the finite element model of degenerative lumbar scoliosis (Cobb angle 10 degrees -20 degrees, 20-30 degrees, more than 30 degrees). The force analysis of L1-L5 bilateral zygapophysial joints each corresponding using the professional finite element software The axial load conditions. 400N is applied to the L1 vertebral body or 400N load combined with 5 N.m 10N.m and 15N.m, the torque force characteristics calculation of each vertebral body. Bilateral facet. Comparative analysis of stress distribution and contact the three corresponding model of facet joint stress. To observe the mechanism of evolution in degenerative facet joints lumbar scoliosis. Results: in the group of type I and type II group, facet asymmetry in the incidence of L3/4 (P=0.011), L4/5 (P=0.043) and L5/S1 (P=0.004) had significant difference. Type II degenerative lumbar scoliosis LL value is significantly less than the type of degenerative lumbar scoliosis LL value (P=0.049) and joint. Angle, PI, LL had no significant difference in the two groups. In two groups, PI and LL were found in association with degenerative lumbar scoliosis. Through the study of the finite element model of facet joint stress change except the movement and lumbar spine related, It is closely related with the severity of bending. After the occurrence of degenerative lumbar scoliosis, facet joint degeneration and compression, cohesion and other changes, leading to more easily find vertebral rotatory dislocation and lateral displacement of lumbar scoliosis. When the lateral bending, slightly curved lumbar scoliosis, convex side facet stress value more than the concave side facet; and in severe bending of lumbar scoliosis, concave facet joint stress is significantly greater than the convex side. When the rotary motion, the convex side of the facet joint tension increases obviously, and the concave side facet was significantly reduced by the compression force closed section. Conclusion: in degenerative lumbar scoliosis, facet joint asymmetry is an important factor causing vertebral rotation. And degenerative lumbar scoliosis with LL decreased or disappeared and corresponding neurological symptoms. The facet joints of lumbar degenerative scoliosis bearing negative The Netherlands is not uniform. Slightly curved, convex side facet joints by large load; moderate and severe bending, concave side facet joints by load. In degenerative lumbar scoliosis, lumbar stress line bias the convex side, the concave side of the vertebral body through regulating the balance of lumbar compression deformation increases, the convex side facet joint space cause lumbar instability, limit the role of facet joint lost maintain vertebral rotation and lateral movement of the vertebral body more easily after lumbar load to the convex side of the lateral displacement and rotation subluxation. The facet joint unbalanced force is caused by lumbar mechanical imbalance, eventually leading to occurrence of degenerative lumbar scoliosis.

【学位授予单位】：第二军医大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R687.3;R318.01

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