基于胫骨止点纤维软骨空间构型的前交叉韧带功能束划分及力学分析研究

发布时间：2018-04-29 02:40

本文选题：前交叉韧带 + 胫骨止点　；参考：《第三军医大学》2015年博士论文

【摘要】：研究背景之前对前交叉韧带(anterior cruciate ligament,ACL)的力学和运动学研究大多是基于ACL功能束划分基础上的,其被划分为前内(anteromedial,AM)和后外(posterolateral,PL)束被广泛接受。划分的依据是膝关节运动过程中AM和PL表现出的不同的张力状态,以及斜矢状位及斜冠状位的磁共振成像(magnetic resonance imaging,MRI)表现。临床上,ACL双束重建的理论基础即是此前内和后外分束。但是,这种划分仍然存在争议。一些学者在尸体膝关节研究中证实ACL存在三束,另外一些学者并没有找到ACL功能束划分的组织学依据。同时,并不是所有的ACL都能被划分为这两束。并且大量的文献研究证实ACL的解剖双束重建的临床疗效并不强于单束重建。ACL经过一个多种组织形成的界面结构插入软骨下骨,这种界面结构促使软组织和硬组织更好的连接,并且在关节运动中使生理负荷更有效地传递。ACL胫骨止点由四种明显不同的组织组成,分别是韧带,非钙化纤维软骨,钙化纤维软骨和骨组织。这种存在局部差异性的分为非钙化组织和钙化组织的界面使止点的力学特性逐渐变化,减小了应力水平,使从韧带到骨的力学负荷传递更有效。非钙化纤维软骨越厚,提示更大的剪切或压缩力。钙化纤维软骨的厚度及和骨的接触程度则和局部拉伸力密切正相关。对ACL胫骨止点纤维软骨分布差异及空间构型的深入理解有助于我们进一步探讨ACL的力学性质。为明确由ACL传递到骨的力学负荷分布,我们分析ACL胫骨止点纤维软骨分布的区域性差异。通过局部非钙化纤维软骨的空间构型,我们以其做为组织学依据间接的将ACL分为不同的功能束。划分的ACL各功能束需要进行解剖位置的定位,本文拟通过数学计算软件计算ACL各功能束的几何中心,根据几何中心的位置来进行定位及命名功能束。ACL做为膝关节最重要的韧带之一,许多实验通过体内、体外及数字模拟的方法来研究它在维持关节稳定性及负荷传递方面的功能。因为ACL复杂的解剖结构和实验的局限性,有限元(finite element,FE)模型能够提供ACL许多有用的信息,而这些是很难从实体研究中获得的。在以前的研究中,加载了简单的负荷条件来分析acl在关节活动中的应力分布。但acl内部纤维束在负荷条件下精确的应力分布仍然存在争议。因此,本研究拟着眼于acl胫骨止点各种组织不同的力学特性来分析其内部纤维束的应力分布。每种止点组织在外力从acl传递到骨的过程中都发挥不同的作用,同时将显著影响acl内部纤维束的应力分布。本研究拟建立一个真实反映acl胫骨止点几何结构的数字模型,并在其中填充网格建立止点fe模型以进行力学分析和数字模拟测试。同时,赋予止点四层结构不同的材料属性,设置边界条件,加载负荷以进行有限元分析,显示acl内部纤维束的应力分布。研究方法1.从本院骨组织库中获取膝关节标本并识别和截取acl胫骨止点。标本经过组织学处理后,间隔50微米(micrometer,μm)进行连续横切片,并行番红o/固绿染色。在光镜下观察切片并摄片。每一张横切片获得数张电子图片,用photoshop软件进行自动拼接获得横切片的完整图像。根据组织学形态和染色来区分止点四层组织包括纤维束、非钙化纤维软骨、钙化纤维软骨和软骨下骨。用photoshop软件手动勾描四种组织的外轮廓,并填充不同的灰度值。把经过photoshop软件处理的完整的灰度值图像输入amira软件,用软件进行三维重建获得模型,不同的组织使用不同的颜色代表。通过amira软件,止点的空间几何构型能够清晰显示。根据其空间构型,将止点非钙化纤维软骨层分为不同的结构单元,并以此划分acl功能束。用amira软件对每个结构单元进行厚度测量。根据非钙化纤维软骨的分区同时测量钙化纤维软骨的厚度。对非钙化纤维软骨层及钙化纤维软骨层的各结构单元厚度进行统计学检验,采用单因素方差分析(one-wayanalysisofvariance),p值设定为0.05。2.通过photoshop软件制作acl胫骨止点各功能束的轮廓线图像,利用matlab软件计算几何中心,依靠acl各功能束几何中心与acl几何中心的相对位置进行功能束的定位,计算其置信度为0.95的置信区间,并进行功能束的命名。3.将输入amira软件的灰度值图像保存为后缀名为“.hmascii”的文件,将此文件输入hypermesh软件,并且在hypermesh软件中这个文件呈现出止点四个部分的原始包络网格模型的形态。在生成匹配原始包络网格的高阶曲面后,删除原始包络网格。各个部分填充四面体元素,之间以节点相连接,最终获得实体网格模型。将hypermes软件生成的实体网格模型输入abaqus软件,各个部分赋予不同的材料属性,骨端的底部固定。将拉伸负荷平均施加于止点近端,沿acl长轴方向。在四个方向上平均的施加剪切负荷,包括从前向后,从后向前,从内向外,从外向内。研究结果1.重建的模型展示了ACL胫骨止点纤维软骨独特的空间构型。根据其空间构型,将非钙化纤维软骨层分为三个结构单元:外侧、内侧和后侧结构单元。相对于内侧单元,外侧单元出现的位置最浅,止点从韧带到非钙化纤维软骨的过渡最早出现在外侧,外侧和内侧单元几乎没有交集,它们通过一个平台将其分开。相对于外侧和内侧单元,后侧单元展示出不同的空间构型,呈现出中空的斜坡状结构。每个单元的非钙化纤维软骨和钙化纤维软骨的厚度有显著性差异,外侧单元最厚,后侧单元最薄,内侧单元介于两者之间。暂时将外侧、内侧及后侧单元分别命名为L、M及P结构单元,与各结构单元相连的纤维束暂时命名为L束、M束及P束。2.L束、M束及P束的几何中心分别位于ACL的外侧、前内侧及后内侧,因此将L束、M束及P束分别命名为外侧束、前内束及后内束。3.用HyperMesh和Abaqus软件构建和模拟止点四层结构包括韧带、非钙化纤维软骨、钙化纤维软骨和软骨下骨的三维FE模型。应力云图显示ACL内部纤维束的拉伸和剪切应力分布不均匀。ACL外侧束应力最低,应力向四周呈放射状的逐渐升高,前内束应力高于外侧束,应力最高的部分位于后内束。研究结论1.基于胫骨止点非钙化纤维软骨空间构型划分ACL功能束为外侧束、前内束、后内束,外侧束的承载能力最大,能够承担更大的拉伸和剪切力,在膝关节活动中起最重要的功能,前内束作用次之,后内束功能作用最弱。临床上,ACL损伤后应重建外侧束。2.通过有限元力学分析证实非钙化纤维软骨厚度与剪切负荷大小呈正相关,钙化纤维软骨厚度与拉伸负荷呈正相关。
[Abstract]:The mechanical and kinematic studies of the anterior cruciate ligament (ACL) before the study are mostly based on the ACL functional bundle division, which are divided into the anterior (anteromedial, AM) and the posterior (posterolateral, PL) bundles widely accepted. The division is based on the different tension of AM and PL during the knee joint movement. Force state, and magnetic resonance imaging (MRI) manifestations of oblique sagittal and oblique coronal position. Clinically, the theoretical basis of ACL double beam reconstruction is the previous internal and posterior fasciculus. However, this division is still controversial. Some scholars have confirmed that there are three bundles of ACL in the cadaver knee research, and some other scholars have not. To find the histological basis of the ACL functional bundle division. At the same time, not all ACL can be divided into these two bundles. And a large number of literature studies have proved that the clinical efficacy of ACL double beam reconstruction is not better than single beam reconstruction of.ACL through a multiple tissue formed interface structure inserted into the subbone of the soft bone, this interface structure promotes soft tissue and The hard tissue is better connected, and the physiological load is more effectively transferred in the joint movement to the.ACL tibial stop, which is composed of four distinct different tissues: ligaments, non calcified fibrocartilage, calcified fibrocartilage and bone tissue. This local difference is divided into the interface of non calcified tissue and calcified tissue to make the stop point. The characteristics gradually change, reduce the stress level, make the mechanical load transfer from the ligament to the bone more effective. The thicker the non calcified fibrocartilage, the greater the shear or compression force. The thickness of the calcified fibrocartilage and the degree of contact with the bone are closely related to the local tensile force. The distribution difference and the spatial configuration of the ACL tibial bone stop point fibrous cartilage In order to further explore the mechanical properties of ACL, in order to clarify the mechanical load distribution from ACL to bone, we analyzed the regional differences in the distribution of ACL tibial fiber cartilage. By the spatial configuration of local non calcified fibrocartilage, we indirectly divided ACL into different functional bundles by using it as a histological basis. The functional bundles of ACL need to be located in the anatomical location. In this paper, the geometric center of the functional bundles of ACL is calculated by mathematical computing software. The location of the geometric center and the named functional bundle.ACL are one of the most important ligaments of the knee joint. Many experiments have passed through the body, in vitro and digital simulation methods to study it. In maintaining the function of joint stability and load transfer. Because of the complex anatomical structure and experimental limitations of ACL, the finite element (FE) model can provide many useful information of ACL, which are difficult to obtain from the entity study. In the previous study, a simple load condition was loaded to analyze ACL in the joint. The stress distribution in the activity is still in dispute. However, the stress distribution of the internal fiber bundles in the ACL is still controversial. Therefore, this study aims to analyze the stress distribution of the internal fiber bundles in different tissues of the ACL tibia. Each stop tissue plays a different role in the process of transferring the external force from the ACL to the bone. The stress distribution of the internal fiber bundles in ACL is significantly affected. In this study, a digital model reflecting the geometric structure of the ACL tibia point is established, and the stop point FE model is built in it to carry out the mechanical analysis and digital simulation test. At the same time, the material attributes of the four layers of stop point are given, and the boundary conditions are set up. Load to carry out the finite element analysis to show the stress distribution of the internal fiber bundles in ACL. Method 1. the specimens of the knee joint were obtained from the bone tissue Library of our hospital and the ACL tibial stop was identified and intercepted. After histological treatment, the specimens were divided into 50 microns (micrometer, M) to carry out continuous transverse section, parallel red o/ green staining. Under the light microscope, the specimen was observed under the light microscope. A number of electronic pictures were obtained for each cross section, and a complete image of the transverse section was automatically spliced with Photoshop software. The tissue morphology and staining were used to distinguish four layers of tissue including fiber bundles, non calcified fibrocartilage, calcified fibrocartilage and subchondral bone. Four tissues were manually traced with Photoshop software. The complete gray value image processed by Photoshop software is input into the Amira software, and the software is used for 3D reconstruction to obtain the model. Different organizations use different colors to represent them. Through Amira software, the geometric configuration of the stop point can be clearly displayed. According to its spatial configuration, the stop point is not The calcified fibrous cartilage layer is divided into different structural units, and ACL functional bundles are divided. The thickness of each structural unit is measured by Amira software. The thickness of calcified fibrous cartilage is measured at the same time according to the partition of non calcified fibrocartilage. The thickness of the structure unit of the non calcified fibrocartilage layer and the calcified soft bone layer is statistically analyzed. The single factor variance analysis (one-wayanalysisofvariance) was used and the p value was set as 0.05.2. to make the contour images of the functional bundles of the ACL tibia point by the Photoshop software. The geometric center was calculated by MATLAB software, and the location of the functional bundles was calculated by the relative position of the geometric center of the ACL function beam and the ACL geometry center, and the confidence was calculated. The 0.95 confidence interval, and the name of the function bundle.3. saves the gray value image of the input Amira software as the ".Hmascii" file with the suffix, input this file into the HyperMesh software, and in the HyperMesh software, the file presents the form of the original envelope mesh model of the stop point in the form of the original matching original. After enveloping the high-order surface of the grid, the original envelope grid is deleted. Each part is filled with tetrahedral elements, and the entity grid model is finally obtained. The entity grid model generated by the hypermes software is input into the ABAQUS software. The different parts are endowed with different materials and the bottom of the bone is fixed. The tensile load is applied on average. At the end of the stop point, along the ACL long axis direction, the average shear load is applied in four directions, including the former and the backward, from the back forward, from the inside to the outside. The 1. reconstruction model shows the unique spatial configuration of the cartilage of the tibial stop point fibrocartilage. The non calcified fibrous cartilage layer is divided into three structural units according to its spatial structure. The lateral, medial, and backside structural units. Relative to the inner element, the lateral element appears to be the most shallow. The transition from the ligaments to the non calcified fibrocartilage appears at the earliest outside, and the lateral and medial units have almost no intersection. They separate them through a platform. The phase is different for the lateral and medial units, and the rear units are different. The thickness of the non calcified fibrocartilage and calcified fibrous cartilage in each unit has a significant difference. The lateral element is the thickest, the posterior element is the thinnest and the inner element is between the two. The lateral, medial and posterior elements are named L, M and P structural units, and the structural units of each unit. The fibrous bundles are named L bundle, M bundle and P bundle.2.L bundle. The geometric center of M bundle and P bundle is located in the lateral, medial and posterior medial of ACL, respectively. Therefore, L bundles, M beam and P bundle are named lateral bundles respectively. The anterior and posterior inner bundles are constructed and simulated with four layers of ligaments, non calcified fibrocartilage and calcium. The three-dimensional FE model of the fibrocartilage and subchondral bone. The stress cloud map shows that the tensile and shear stress distribution of the internal fiber bundles in ACL is the lowest in the lateral bundle of.ACL, the stress rises to the periphery, the stress of the anterior internal beam is higher than the lateral beam, and the most stress is in the posterior inner bundle. Conclusion 1. based on the non calcium at the tibia stop point. The spatial configuration of the fibrocartilage is divided into the ACL function bundle as the lateral bundle, the anterior internal bundle, the posterior inner bundle and the lateral bundle are the most carrying capacity, and can bear the greater tensile and shear force. It plays the most important function in the knee joint activity. The anterior internal beam is the second and the posterior fasciculus function is the weakest. In clinical, the lateral bundle should be rebuilt by the limited.2. through the ACL injury. Meta mechanics analysis showed that non calcified fibrocartilage thickness was positively correlated with shear load. Calcified fibrocartilage thickness was positively correlated with tensile load.

【学位授予单位】：第三军医大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R686

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