生长期脊柱结核外科治疗策略及基础研究

发布时间：2018-01-13 06:23

本文关键词：生长期脊柱结核外科治疗策略及基础研究　出处：《武汉大学》2016年博士论文　论文类型：学位论文

【摘要】：目的：生长期脊柱结核无论是在结核活跃期还是在愈合期,都会出现脊柱畸形角进行性改变。脊柱结核病人在其生长过程中因为椎体生长加速或抑制可能出现后凸畸形加重,减轻,不变。脊柱椎体在椎体压力的影响下生长。有限元方法已经成为研究脊柱生物力学的一种有效方法,能分析终板,椎间盘,关节突关节的应力值及非常详细的动态数据。在有限元软件的帮助下可以形成各种各样的模型,经过分析参数,知道虚拟有限元模型和具体的病例相似的生物力学参数。内固定力学负荷并非完全阻滞脊柱的生长潜能,而是延缓了其生长速度,当发现力学负荷矫枉过正时,解除相应力学负荷,患者仍可保留生长潜能。采用经CT三维重建椎弓根来测量生长期儿童胸、腰段椎弓根的宽值、高度值、内倾角以及椎弓根长度值。随后以前期形态学研究结果为指导,采用后路椎弓根钉棒系统固定联合腔镜辅助下微创前路病灶减压、植骨融合手术治疗生长期脊柱结核,内固定装置被安排在不同时间取出,目的为了知道手术及内固定与生长期脊柱结核后突畸形和生长率的关系,同时探讨微创技术在生长期儿童脊柱疾患治疗中的价值应用价值。基于生长期脊柱结核有限元模型研究椎体生长板局部应力及生物学内固定对脊柱生长调控的影响规律。方法：本项目是由两部分组成。基于生长期脊柱结核有限元模型研究椎体生长随应力变化的关联规律。(1).病例研究样本的收集分组根据已经获取的生长期脊柱结核病例年龄在0-16岁间,选择的病例包括胸椎结核和腰椎结核,一些病例是单个椎间隙,而另外一些病例是多节段。入选病例要求具有生长期结核活跃期及愈合期1年,2年以及最终随访的畸形角度以及塌陷椎体高度(椎体前缘、后缘高度)变化的完整资料。(2).建立三维CT图像资料库每一个入组的脊柱结核病例,病变及邻近椎体都进行了螺旋CT机器的扫描。重建后层薄0.625mm,该部位的断层层厚小于1mm,因为层厚厚度决定了根据其建立的三维图像的精细度,数据活动的越多,能够使有限元分析形成更为准确的原始数据。扫描条件：病人标准的平躺,CT的电压120千伏,电流320毫安,螺距0.75毫米。扫描后获得的断面图像,它的DICOM数据大小为515 kb千字节。(3).图像处理采用三维重建软件Materialise Mimics,将DICOM格式保存在软件中,将图像进行筛选处理,获得图像。调节图像的对比度,删除软组织阴影,判定目标的阈值。Mimics将根据不同的阈值自动提取不同组织的轮廓边界,然后再利用反向填充功能对椎体修补,避免了生成实体后其中有空穴,对以后的网格划分造成影响。由三维重建软件重建几何3D模型,然后将其导入Mimics软件中,根据其Magic 9.9网格划分工具,对获得的三维图像进行网格划分,经过初步光滑、提高网格的质量及自动检测网格质量等步骤,获得满意的预区分网格的三维图像数据,用LIS格式文件将其产生,等等进一步的处理。(4).三维有限元模型的建立将Mimics中生成胸、腰脊柱几何模型的LIS格式文件输入到前处理软件ANYSY10.0,采用网络质量检查、光滑处理等操作再次处理网格,根据参考文献给模型给予材料属性。完成了几何建模和单元格材料属性的设置后,选用自由网格划分法,运行ANYSY程序的实体生成功能(Volume Meshing基于表面网格生成实体)自动划分生成基于有限元网格实体模型,并采用自动网格化分来生成节点和单元,建立生长期脊柱结核的有限元模型。(5).应力分析采用Pro/Ansys 6.0有限元软件,对模型进行处理和数据的计算。得出不同负荷条件下模型的Von mises应力云图分布。(6).研究椎体生长随应力变化的关联规律根据生长期脊柱结核活跃期及愈合期后凸畸形变化及塌陷椎体高度(椎体前缘、后缘高度),及有限元分析其椎体生长板的应力关系,阐述椎体生长随应力变化的关系。基于生长期脊柱结核病例经腔镜辅助下微创治疗及生物内固定后的有限元模型探讨外科治疗及脊柱内固定后的应力变化及脊柱内固定对生长期脊柱畸形变化的影响规律(1).生长期椎弓根参数测量及其随年龄变化规律将生长期各个年龄段的胸、腰脊柱椎弓根进行CT检查,通过三维重建技术分别在横断面,矢状面及冠状面分析各个年龄段椎弓根的角度、宽度、椎弓根轴心、与棘突轴心线及与椎体水平线的夹角以及长度变化。将所获的的参数数据记录入电脑,并进行统计分析,确立不同年龄段胸段和腰段椎弓根各种参数的变化范围。分析参数随年龄的变化趋势。(2).建立三维CT图像资料库根据已经获取的经后路椎弓根钉棒系统固定联合腔镜辅助下微创前路病灶减压、植骨融合手术治疗生长期脊柱结核病例,经治病例分为三组,对不同组别病例分别在1年,1.5年和2年时间拆除后路内固定器械(为累及单节段的生长期脊柱结核病例)。对所有病例分别记录手术前后,术后0.5年,1年,2年以及最终随访的畸形角度以及塌陷椎体前缘高度变化。每一个入组的脊柱结核病例,病变及邻近椎体都进行了螺旋CT机器的扫描。重建后层薄0.625mm,该部位的断层层厚小于1 mm。建立三维CT图形资料库。(3).基于有限元椎体生长板应力分析对模型进行计算及数据的处理采用Pro/Ansys 6.0有限元软件。不同时期拆除病人内固定后获得的生长期脊柱结核模型,分析其Von mises应力云图分布。(4).统计分析对比分析不同组别结果变化,以确定应用后路椎弓根钉棒系统固定联合腔镜辅助下微创前路病灶减压、植骨融合外科治疗生长期脊柱结核,及该方法对生长期畸形和生长率变化的影响规律,并探讨外科治疗及内固定对椎体生长板压力及椎体生长的影响规律。结果：(1)根据已经获取的生长期脊柱结核病例,建立三维CT图像资料库(包括活跃期及愈合期)(2)前期获得CT图像,将其放入三维重建软件也就是Materialise Mimics中,进行CT图像处理(3)建立生长期脊柱结核的有限元模型,得出加载条件下模型的Von mises应力云图分布(4)临床观察：四种脊柱结核模型的建立,临床观察与四种脊柱结核模型类型和具体的脊柱生长变化的关系。A型：它对应于一组脊柱结核病变位局限于一个椎间盘,伴随整个椎间盘的破坏和临近节段椎间盘和椎体松质骨的破坏,再稳定发生于整个椎体骨面的完全接触并且后柱融合。B型：伴随椎间盘的浸润,更多的椎体骨质被破坏,相应关节突关节发生脱位,前方塌陷后通过点接触发生再稳定。C型：一个椎体的完全破坏和邻近椎体的部分破坏,两个阶段的关节突关节发生脱位,前方再稳定伴随着上位椎体的旋转,导致融合块的完全抑制生长和未涉及节段椎体松质骨的广泛破坏。D型：多节段椎体破坏和关节突关节脱位,再稳定完全发生于上位椎体完全倾倒,上位椎体90度的旋转导致椎体前面和下位椎体的上面接触。(5)脊柱塌陷和在稳定的类型决定了脊柱生长模式的变化和脊柱畸形的进展。A型和D型脊柱发生了过度生长,而B型和C型生长发生了抑制。在A类型中,加速生长局限于椎体生长的前半部分,后半部分很少发生变化。加速生长(前半部分生长速度/后半部分生长速度*100)变化范围从15到高达120。相比之下,类型D加速生长的情况更小,前半部分和后半部分均等,在代偿曲线下脊柱序列产生高或者长的椎体。在B类型中,当后凸畸形超过40度时,生长迟缓发生于融合骨块的前半部分,也发生于后凸范围内的正常椎体。这导致融合椎在生长过程中前后比率的减小,也产生邻近椎体的楔形变。一旦后凸畸形超过40°,位于关节突关节的关节囊压力和椎体终板压力具有重要意义的增加,它会产生前后生长比率的减小和后方关节突关节不同程度的半脱位。在C型中,随着畸形程度的迅速增加,椎体生长受到完全抑制。生长模式的改变不仅发生于融合椎体,也在扩展到原发弯和代偿弯产生镜像反应。(6)有限元模型的印证：通过创建严重畸形及加载负荷,在临床上观察到的这四种类型可以在有限元中准确的复制。这样,我们据此就可以测算前柱的压应力和后柱的张应力。(7)在类型A中,关节囊压力少量增加(2Mpa),因为前方有大量的接触面。在其他类型的脊柱结核模型中,关节囊压力和棘上韧带压力惊人的增加。最开始发生于相应节段的关节,接下来发生于邻近上下节段,意味着序列失代偿。这个情况下我们就可以发现到发生了关节突关节脱位。(8)即使后凸畸形的微小变化,也会增加椎间盘前半部分和椎体终板的压应力,而在点接触中,压应力会突然增加。在这四种类型中,接触压应力的变化范围非常大,可以从类型A的1MPa迅速增加的到类型B的16.6MPa和类型B的40MPa,在椎体终板前半部分压应力增加和后凸的增加存在相关性。但是在类型D中,存在矛盾性压应力翻转,椎体终板的压应力减小到1 MPa。在这种情况下,后凸畸形几乎达到180度,椎体终板变成了垂直,这样压应力可以忽略不计。在这些类型中,后柱发生失代偿,椎体松质骨的压应力增加到40 MPa,就会达到松质骨坏死的阈值。结论：生物力学因素在脊柱的生长发育过程中起重要作用,张应力和压应力分别都是其影响因素,影响椎体终板的生长变化,由此而产生的生长不平衡,因此获得的规律在临床工作具备指导意义。而生长期脊柱结核因为比较特殊脊柱畸形改变情况,在临床工作中,其治疗是一个难点,因为其病变的特殊性往往也给许多患者产生经济和心理方面的巨大影响。由此形成我国生长期儿童胸、腰椎弓根各个年龄段参数的变化规律。应用后路椎弓根钉系统固定,联合腔镜辅助下微创前路病灶减压、植骨融合手术治疗生长期脊柱结核是一种有效的方法。通过构建生长期脊柱结核有限元模型,获得椎体终板局部应力和脊柱内固定对脊柱生长调控的影响,负荷的规律是软骨生长应力曲线,而Hueter-Volkmann定律不能解释一下现象,即张应力会生长加速,而压应力在一定的范围内促进生长,超过一定的范围则抑制生长。
[Abstract]:Objective: the growth period of spinal tuberculosis both in active TB or in the healing period, there will be a spinal deformity angle change. Patients with spinal tuberculosis in the growth process because of the vertebral growth may be accelerated or inhibited the increase of kyphosis, reduce spinal vertebral body unchanged. In the influence of pressure under finite element growth. The method has become an effective method of study on spinal biomechanics, analysis of endplate, intervertebral disc, facet joint stress value and dynamic data in great detail. In the finite element software can help form a variety of models, through the analysis of parameters, know the biomechanical parameters of virtual finite element model and the specific cases of similar the growth potential of internal fixation. Mechanical load is not completely block the spine, but delayed the growth rate, when the mechanical load overkill, lift the corresponding mechanical load, Patients can still maintain growth potential. The three-dimensional reconstruction of CT pedicle to measure the growth of breast in childhood, lumbar pedicle width, height value, inner angle and pedicle length. Then in the early morphological study results, using posterior pedicle screw fixation combined with minimally invasive video-assisted anterior decompression, bone graft fusion surgical treatment of spinal tuberculosis in the growth period, the fixed device is arranged out at a different time, in order to know the operation and internal fixation and growth of the relationship between spinal tuberculosis kyphosis and the growth rate, while creating value and application value to explore the micro technology in growing children of spinal disorders in the treatment of spinal tuberculosis. During the growth period of research on finite element model the vertebral growth plate local stress and biological fixation on spinal growth based on the control. Methods: this project is composed of two parts. Based on the growth of The finite element model of spinal tuberculosis of the vertebral growth with the associated rules of stress change. (1). Case study samples were collected according to the packet has been acquired during the growth period of spinal tuberculosis cases aged between 0-16 years old, including selected cases of thoracic tuberculosis and lumbar tuberculosis, some cases are single intervertebral space, and some cases are multi section. Cases with growth period of active TB and healing period of 1 years, 2 years and the final follow-up deformity angle and vertebral height (vertebral collapse, posterior height) complete data change. (2). The establishment of three dimensional CT image database of each group of spinal tuberculosis cases, lesions and all the adjacent vertebral spiral CT machine scanning. After reconstruction of thin layer of 0.625mm, the fault of the parts of the layer thickness is less than 1mm, because the thick layer thickness determines the three-dimensional image according to the granularity of data, the more active, To make finite element analysis of the formation of more accurate data. Scanning conditions: flat patient standard, CT 120 thousand volts, current 320 Ma, pitch 0.75 mm. The section scanned images of DICOM data, its size is 515 KB Kbytes. (3). Image processing using 3D reconstruction software Materialise Mimics, DICOM format will be stored in the software, the image filter processing, image adjustment. The contrast of the image, remove the soft tissue shadow threshold.Mimics determine the target will be based on different threshold automatic extraction of contour boundary in different tissues, and then use the reverse filling function of vertebral body repair, avoid generation of entity after the hole, the impact on the future grid. By three-dimensional reconstruction software, the geometry model of 3D, and then imported into Mimics software, according to the Magic 9.9 grid row out of the three division. Dimensional image grid, after a preliminary smooth, improve the quality of mesh and mesh quality automatic detection procedures, three-dimensional image data obtained satisfactory pre distinguish grid, using the LIS format file, and further processing. (4). Three dimensional finite element model will generate Mimics in the chest, lumbar spine the geometric model of LIS format input to the pretreatment software ANYSY10.0, the network quality inspection, smooth handling of re processing grid, according to the reference model to give material properties. The geometrical modeling and cell setting material property, using the free mesh method, generating function entity to run the ANYSY program (based on Volume Meshing generate entity surface mesh) automatic division of finite element mesh generation model based on entity, and the automatic mesh generation of nodes and elements, the establishment of spinal growth The finite element model of tuberculosis. (5). Stress analysis using Pro/Ansys 6 finite element software, calculation processing and data to the model. The model under different load conditions Von Mises stress distribution. (6). Study on the vertebral growth with the associated rules of stress change according to the growth stage of spinal tuberculosis in active period and the healing period of kyphosis change and collapse of vertebral height (anterior vertebral body, posterior height), and finite element analysis of the vertebral growth plate stress relationship, this relationship with the growth of the vertebral stress changes. The growth period of spinal tuberculosis cases based on endoscopic assisted minimally invasive treatment and biological in finite element model after fixed to explore the surgical treatment and after spinal fixation stress changes and spinal fixation effect rule of the growth period of spinal deformity (1). The variation of growth period and its changes with age pedicle parameter measurement Law of growth period in different age groups The chest, lumbar spinal pedicle were examined by CT, respectively in cross section by three-dimensional reconstruction technique, sagittal and coronal analysis of each age segment pedicle angle, width of pedicle axis angle with the axis line of spinous process and vertebral horizontal line and length change. The obtained parameters of the data into the computer. And carries on the statistical analysis, changes in the scope of the establishment of various parameters of different ages of pedicle of thoracic and lumbar spine. Analysis of parameters change with age. (2). Three dimensional CT image database based on posterior pedicle screw rod system fixation combined with minimally invasive video-assisted anterior decompression has been obtained, bone graft fusion surgery the growth of spinal tuberculosis patients after treatment were divided into three groups of different groups were respectively in 1 years, 1.5 years and 2 years of posterior internal fixation devices for demolition (involving the single segment growth period of spinal tuberculosis In all cases). Cases were recorded before and after surgery, 0.5 years after 1 years, 2 years and the final follow-up deformity angle and anterior height of vertebral body collapse changes. Each group of spinal tuberculosis cases, lesions and adjacent vertebral bodies were spiral CT machine scanning. After reconstruction of thin layer 0.625mm fault the parts of the layer thickness is less than 1 mm. to build 3D CT graphics database. (3). The finite element stress analysis of vertebral growth plate model calculation and data processing using Pro/Ansys 6 finite element software. Based on the different period to remove growth period model of spinal tuberculosis patients after internal fixation is obtained, analysis of the Von Mises stress nephogram distribution. (4). Statistical analysis results of different groups, to determine the application of posterior pedicle screw fixation combined with minimally invasive video-assisted anterior decompression, bone graft fusion and surgical treatment of spinal tuberculosis and the growth period. Methods on the growth effect of deformity and the growth rate of change, and to explore the influence of fixation on vertebral growth plate pressure and vertebral growth and surgical treatment. Results: (1) according to the growth stage of spinal tuberculosis cases, the establishment of three-dimensional CT image database (including the active period and early healing) (2) to obtain CT image into three-dimensional reconstruction software, namely Materialise Mimics, CT image processing (3) to establish the finite element model of spinal tuberculosis in growth period, the loading model of the Von Mises stress distribution (4) clinical observation: establish four spinal tuberculosis model, the relationship between type.A clinical observation with four kinds of spinal tuberculosis model and specific types of spinal growth changes: it corresponds to a set of spinal tuberculosis displacement confined to a disc, with the disc damage and adjacent intervertebral disc and vertebral body Cancellous bone destruction and stability occur in the whole vertebral bone surface contact and posterior column fusion type.B: with the infiltration of the intervertebral disc, more vertebral bone destruction, dislocation of the corresponding facet joint, and stable.C type point contact through the front after the collapse: the destruction of a complete destruction of vertebral body and adjacent part of the vertebra, dislocation of the two stages of the facet joint, the front again with the stable upper vertebral body rotation, resulting in complete inhibition of growth and not involved vertebral cancellous bone destruction type.D fusion block: vertebral destruction and facet joint dislocation, then stability occurred in the upper vertebral body the toppling of the upper vertebra rotation of 90 degrees in front of the vertebral body above contact. (5) and the collapse of the spine in a stable type determines the spinal growth pattern changes and spinal deformity of.A type D and the occurrence of spinal overgrowth, B type and C type growth were suppressed. In type A, accelerate the growth of limited first half to the vertebral growth, the second part rarely change. Accelerated growth (first half growth rate / second half growth rate of *100) range from 15 to as high as 120. in contrast, type D accelerated growth of the smaller front part and the second part is equal, in the compensation under the curve of spinal column sequence produce high or long. In the B type of vertebral kyphosis, when more than 40 degrees, growth retardation occurred in the first half of the normal vertebral bone fusion, convex range also occurred after. This leads to the decrease of vertebral fusion rate before and after in the growth process, also produce adjacent vertebral wedging. Once the kyphosis exceeds 40 degrees, the increase has important significance in the facet joint capsule pressure and pressure of the vertebral endplate, It will have reduced and the growth ratio before and after the rear facet of different degree of subluxation. In type C, with the rapid increase in the degree of deformity, vertebral growth was completely inhibited. The growth pattern of change not only occurred in the fusion of vertebral body, also extended to primary bending and compensatory bending generating mirror reaction. (6) Co. the meta model confirmed by creating severe deformity and load, the four types observed in the clinical setting can be replicated accurately in finite element. In this way, we can calculate the anterior column after column compressive stress and tensile stress. (7) in type A, a small amount of intraarticular pressure increase (2Mpa), because the front of a large contact surface. In the model of spinal tuberculosis of other types, increase the pressure of the joint capsule ligament striking pressure and spine. First occurred in the corresponding segments of the joint, then occurred in the adjacent segment, mean A sequence of decompensation. In this case we can find the facet joint dislocation (8). Even small changes in kyphosis, will also increase the intervertebral disc half and vertebral endplate stress, and in point contact, the compressive stress will increase suddenly in the four. The type, range of contact stress is very large, can rapidly increase from type A to type B 1MPa and type B 16.6MPa 40MPa, in the first half part of the vertebral endplate stress increase and kyphosis increase correlation. But in type D, contradictory stress reversal, vertebral endplate stress decreases to 1 MPa. in this case, the kyphosis reached almost 180 degrees, the vertebral endplates became vertical, so the compressive stress can be neglected. In these types, the posterior column of decompensation, vertebral cancellous bone compressive stress increased to 40 MPa, can be achieved loose Bone necrosis threshold. Conclusion: biomechanical factors play an important role in the process of spinal growth, tensile stress and compressive stress are the influencing factors affecting the growth of vertebral endplate changes, the resulting growth is not balanced, so the law have guiding significance in clinical work. The growth period of spine tuberculosis is rather special because spinal deformity changes, in clinical work, the treatment is very difficult, because of the huge influence of its special lesions tend to many patients with economic and psychological aspects. The formation of China's growth of thoracic lumbar pedicle in children, of all ages

【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R687.3

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