腰椎椎间高度的动态变化特点与腰椎小关节假体的研制

发布时间：2018-06-12 23:34

本文选题：腰椎小关节 + 动力学　；参考：《南方医科大学》2017年博士论文

【摘要】：背景当今社会,腰椎退变性疾病带给人们的困扰越来越大;因而相关的研究及治疗方案也在不断革新。在手术治疗方面,减压融合固定手术被看作当前治疗腰椎椎管狭窄、椎间盘退变性疾病等疾病时应用最为广泛的手术方式。但是,根据近期长期随访观察结果显示,融合手术会出现加速邻近腰椎节段退变等不足。针对这些临床问题,相关学者提出了保留腰椎活动的手术方式,即非融合手术的观点。此类手术的目的是保留病人腰椎的活动度,减少融合手术带来的邻近节段病的发生。在相对应的手术中,腰椎人工小关节置换术能够处理较多的临床问题,受到学者们的关注。但是,现有的小关节假体并未普及;究其原因主要是现在的小关节假体型号单一,不适合我国人群;或者结构不理想,会出现器械破损等临床问题。因此需要根据国人正常腰椎解剖参数,设计一种适合国人的新型腰椎小关节假体。方法1.利用自制生物力学实验装置模拟腰椎在6Nm力偶矩作用下的运动并行CT扫描,同时验证该实验方法的精确性与可重复性。2.应用三维重建技术获得腰椎不同位置的3D模型;测量腰椎不同节段椎间高度在屈伸、侧弯过程中的变化特点。3.设计腰椎小关节假体模型,利用有限元分析法对小关节假体进行相关生物力学分析,并根据分析结果进一步优化假体结构,同时申请专利保护。4.生产出小关节假体,并利用人腰椎尸体标本对假体进行生物力学体外实验。结果1.成功制作出了可用于CT扫描的腰椎力学加载装置,并且具有较高的精确性与可重复性。2.在腰椎中立位-前屈位活动时,所有节段椎间盘的前高变化幅度均随着节段增加而增加(L3/4:1.56 ± 0.30mm,L4/5:2.06 ± 0.62mm,L5/S1:2.50 ± 0.93mm);在中立位-后伸位时,L4/5节段椎间盘前后高的变化幅度相近,但是在L3/4、L5/S1节段,此过程中其前高的变化要比后高的变化大;而在侧弯时,侧弯方向的椎间盘侧方高度变化值明显比对侧的椎间盘侧方高度大,而人字嵴间距呈现与之相反的趋势。3.建立了正常人腰椎(L2-L5)有限元分析模型。椎间ROM比较显示:腰椎小关节假体组的活动范围比钉棒固定组大,但接近于正常腰椎组;假体组应力主要集中关节假体的上半部分与椎弓根螺钉连接处。4.体外实验显示小关节假体组的腰椎刚度与正常组的接近,而小于钉棒组的腰椎刚度。结论1.腰椎的椎间盘高度和人字嵴间距在屈伸、侧弯运动时呈现节段特异性的变化。2.有限元分析显示:腰椎小关节假体可以为腰椎提供一定的生物力学稳定性。3.离体标本实验显示腰椎小关节假体作为一种新型的非融合内固定技术,融合后整体结构稳定性接近于正常腰椎。
[Abstract]:Background in today's society, lumbar degenerative disease brings more and more problems to people; therefore, related research and treatment programs are constantly innovating. In the aspect of surgical treatment decompression fusion fixation is regarded as the most widely used surgical method in the treatment of lumbar spinal stenosis disc degeneration and other diseases. However, according to the recent long-term follow-up results, fusion surgery may lead to accelerated adjacent lumbar segment degeneration and other deficiencies. In order to solve these clinical problems, some scholars put forward the idea of non-fusion surgery, which is the method of preserving lumbar vertebrae activity. The aim of these operations is to preserve the patient's lumbar mobility and to reduce the incidence of adjacent segmental diseases associated with fusion surgery. In the corresponding surgery, lumbar artificial facet arthroplasty can deal with more clinical problems, which has attracted the attention of scholars. However, the existing facet joint prosthesis is not popularized; the main reason is that the current small joint prosthesis model is single, which is not suitable for the Chinese population; or the structure is not ideal, there will be clinical problems such as device breakage and so on. Therefore, it is necessary to design a new lumbar facet joint prosthesis based on normal lumbar vertebrae anatomical parameters. Method 1. The self-made biomechanical experimental device was used to simulate the motion of lumbar vertebrae under the action of 6Nm force couple moment and CT scan. The accuracy and repeatability of the experimental method were also verified. Three-dimensional reconstruction technique was used to obtain 3D models of lumbar vertebrae in different positions and to measure the changes of lumbar intervertebral height during flexion extension and lateral bending. The model of lumbar facet joint prosthesis was designed, and the biomechanical analysis of facet joint prosthesis was carried out by using finite element analysis, and the structure of the prosthesis was further optimized according to the analysis results, and the patent protection was applied for. Facet joint prostheses were produced and biomechanical experiments were carried out on human lumbar vertebrae cadavers in vitro. Result 1. A mechanical loading device for lumbar vertebrae which can be used for CT scanning is successfully fabricated, and it has high accuracy and repeatability. In neutral position and anterior flexion of lumbar vertebrae, the changes of anterior height of all segments of intervertebral disc increased with the increase of segments, and the changes of L 3 / 4: 4: 4: 56 卤0.30 mm and L / 4: 5: 0. 62 mm / L 5 / S 1: 1: 1: 2. 50 卤0. 93 mm of lumbar intervertebral disc were similar in neutral position and extension position, and the height of L4 / 5 segment of intervertebral disc was similar in neutral position and extension position, and the change of L4 / 5 segment height was similar to that of L4 / 5 segment in neutral position and extension position. But in the L3 / 4 / L5 / S1 segment, the change in the front height is greater than that in the posterior segment, and in the lateral bend, the lateral height of the disc in the lateral bending direction is significantly larger than the lateral height of the contralateral intervertebral disc. The spacing of herringbone cristae showed the opposite trend. 3. A finite element model of L 2-L 5) for normal lumbar vertebrae was established. The results showed that the range of motion in the lumbar facet joint prosthesis group was larger than that in the pedicle fixation group, but close to that in the normal lumbar vertebrae group, and the stress in the prosthesis group mainly concentrated on the upper half of the joint prosthesis and the pedicle screw junction. 4. In vitro experiments showed that the lumbar stiffness of the facet joint prosthesis group was similar to that of the normal group, but less than that of the screw rod group. Conclusion 1. Lumbar disc height and herringbone crest spacing showed segmental specific changes during flexion and lateral bending. Finite element analysis shows that the lumbar facet joint prosthesis can provide certain biomechanical stability. As a new non-fusion internal fixation technique, the whole structure stability of lumbar facet joint prosthesis is similar to that of normal lumbar vertebra.
【学位授予单位】：南方医科大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R687.3

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