胸腰段椎體骨折后路內(nèi)固定術(shù)后傷椎骨缺損的生物力學(xué)有限元分析
發(fā)布時間：2019-06-17 12:30
【摘要】：目的:對胸腰椎骨折術(shù)后出現(xiàn)傷椎終板塌陷的病人,建立有限元模型對該類患者是否適合取出內(nèi)固定進行生物力學(xué)分析。方法:(1)實驗對象:招募男性志愿者一名,通過病史詢問及X線等影像學(xué)檢查,脊柱無畸形、無外傷、無腫瘤等其他脊柱病變。(2)資料采集設(shè)備:志愿者取自然狀態(tài)平臥位,自Ti1-I3椎體行水平薄層掃描,獲得144張相應(yīng)節(jié)段水平截圖。掃描的數(shù)據(jù)資料以DICOM格式導(dǎo)出,并刻錄光盤儲存,以便于Mimics15.0醫(yī)學(xué)圖像處理軟件處理圖像數(shù)據(jù)。(3)建立Ti1-L3的胸腰椎三維有限元模型:將數(shù)據(jù)導(dǎo)入到Mimics15.0醫(yī)學(xué)圖像處理軟件中,利用Draw Profile Line及Thresholding功能,將圖像閾值調(diào)節(jié)為462-2676HU,使腰椎各部分的界限更清楚。利用區(qū)域增長可將上述蒙版上彼此不相連的分割區(qū)域形成一個新的蒙版。利用Region Growing功能可粗略提取感興趣的腰椎各個節(jié)段。利用軟件的三維空間建模功能,將經(jīng)過斷層圖像處理后的數(shù)據(jù)進行三維模型建模,建立各個椎體的,獨立的三維表面骨骼模型。為了使模型更加真實平滑,對各個模型分別設(shè)定適當(dāng)?shù)膮?shù),從而更加清楚直觀的地再現(xiàn)胸腰段椎體骨結(jié)構(gòu)的三維立體形態(tài)。由此建立的三維圖像,可以在軟件中進行垂直壓縮、左右平移及旋轉(zhuǎn),可以對脊柱功能進行全方位的演示。還可根據(jù)研究的實際情況,對不需要的功能進行隱藏、刪除,增加、合并需要的功能以獲得不同的外觀和效果。SolidWorks軟件包含網(wǎng)格處理向?qū)Ъ扒嫔上驅(qū)Чδ?利用這兩個功能可以將各椎體的點云文件生成實體零件,處理過程包括對模型進行除噪點、平滑、曲面擬合等,同時使用草圖功能繪制釘棒系統(tǒng)的輪廓圖,并使用拉伸、旋轉(zhuǎn)等功能獲得釘棒系統(tǒng)的實體模型,然后使用工程圖精確定位裝配模型。將SolidWorks軟件中建立的裝配體導(dǎo)入HyperMesh軟件,利用HyperMesh軟件強大的網(wǎng)格制作及剖分功能,將裝配體網(wǎng)格化,同時構(gòu)建皮質(zhì)骨,設(shè)定厚度1mm,四面體網(wǎng)格劃分尺寸分別為:腰3-腰5為2mm,骶1為3mm,釘棒系統(tǒng)為1mm。按照解剖部位和形態(tài),補充胸腰段各附屬解剖結(jié)構(gòu),如終板、纖維環(huán)、髓核、關(guān)節(jié)突軟骨,用Truss單元模擬椎體間存在的7種不同的韌帶結(jié)構(gòu),包括前縱韌帶、后縱韌帶、橫突間韌帶、棘上韌帶、棘間韌帶、黃韌帶、關(guān)節(jié)囊韌帶等結(jié)構(gòu),以及上下關(guān)節(jié)突,軟骨等結(jié)構(gòu),獲得胸11-腰3的三維有限元模型,該模型具有147064單元和39157個節(jié)點組成。(4)驗證模型的有效性及精確度:本模型中各項材料賦值是根據(jù)國內(nèi)外醫(yī)學(xué)者公認的文獻賦值,并且運算加載的數(shù)據(jù)參數(shù)也是根據(jù)最新的研究成果來設(shè)定的。本實驗采用網(wǎng)格劃分功能較強的Hypermesh軟件來劃分網(wǎng)格,提高了網(wǎng)格的質(zhì)量,并采用了自適應(yīng)能力強的C3D4四面體單元,能夠在可接受的時間內(nèi)運算出精確的結(jié)果。5、建立傷椎缺損椎體模型:建立5種傷椎上終板的骨缺損模型,缺損體積設(shè)定為占傷椎前柱體積的1/5、2/5、3/5、4/5、5/5。分別對裝配內(nèi)固定及取出內(nèi)固定的5種模型施加各類載荷,對其受力情況進行生物力學(xué)分析,統(tǒng)計數(shù)據(jù)做圖表及趨勢圖分析。結(jié)果:從正常椎體受力云圖中我們可以發(fā)現(xiàn),垂直狀態(tài)下椎體前2/3及椎體終板的后部及近椎弓根處是正常椎體的應(yīng)力集中區(qū),并向后外側(cè)呈放射狀分布;很明顯皮質(zhì)骨尤其是椎體前緣所受應(yīng)力高于松質(zhì)骨;當(dāng)椎體前后及側(cè)向屈伸運動時,屈側(cè)及伸側(cè)以及椎弓根附近均出現(xiàn)應(yīng)力集中現(xiàn)象。在打入釘棒系統(tǒng)的模型中,5種上終板塌陷(缺損體積分別為椎體前柱的1/5、2/5、3/5、4/5、5/5)模型,在垂直、前后屈、側(cè)屈、左右旋轉(zhuǎn)下的應(yīng)力分布圖可以看出,植入內(nèi)固定后,隨著傷椎缺損體積不斷增大,應(yīng)力也相應(yīng)增大,且隨著傷椎上終板塌陷及前柱骨缺損體積逐漸增大,應(yīng)力逐漸向內(nèi)固定集中。而取出內(nèi)固定后,5種上終板塌陷模型的受力圖顯示隨著內(nèi)固定的取出,失去了內(nèi)固定的支持后,隨著缺損體積的增加,應(yīng)力逐漸變大。從點線圖中可以看出,取出內(nèi)固定后在應(yīng)力逐漸增加的趨勢下,隨著缺損體積的增加,當(dāng)缺損體積達到傷椎前柱4/5并繼續(xù)增加時,E組(4/5缺損組→5/5缺損組應(yīng)力差)傷椎所承受的7種工況的綜合應(yīng)力增加幅度最大。意味著此時傷椎對載荷承載能力顯著下降,增加的集中應(yīng)力將導(dǎo)致傷椎前柱再次骨折。此時取出內(nèi)固定,塌陷的傷椎不足以維持穩(wěn)定性,增加的生物力學(xué)應(yīng)力有導(dǎo)致其出現(xiàn)繼續(xù)壓縮甚至再次骨折的風(fēng)險。結(jié)論:通過有限元法模擬傷椎上終板塌陷,計算分析隨缺損體積變化的傷椎應(yīng)力改變,當(dāng)缺損體積達到傷椎前柱4/5并繼續(xù)增加時,傷椎所承受的7種工況的綜合應(yīng)力增加幅度最大。意味著此時傷椎對載荷承載能力顯著下降,增加的集中應(yīng)力將導(dǎo)致傷椎前柱再次骨折。此時取出內(nèi)固定,塌陷的傷椎不足以維持穩(wěn)定性,增加的生物力學(xué)應(yīng)力有導(dǎo)致其出現(xiàn)繼續(xù)壓縮甚至再次骨折的風(fēng)險,而當(dāng)缺損體積達到前柱3/5時,就應(yīng)慎重考慮內(nèi)固定的取出,但此現(xiàn)象及臨床治療仍需進一步的研究。
[Abstract]:Objective: To establish a finite element model for the biomechanical analysis of the patients with the collapse of the vertebral endplates after the fracture of the thoracolumbar fracture. Methods: (1) Experimental subjects: one of male volunteers was recruited, including medical history, X-ray and other imaging examinations, and there were no other spinal diseases such as spinal deformity, no trauma, and no tumor. (2) Data acquisition equipment: volunteers take the natural state horizontal position, and scan the horizontal thin layer from the Ti1-I3 vertebral body to obtain the horizontal screenshot of 144 corresponding sections. The scanned data is derived in a dicom format and is recorded on an optical disc for processing the image data in the mmoics15.0 medical image processing software. (3) The three-dimensional finite element model of the thoracic and lumbar spine of Ti1-L3 was established: the data was introduced into the Mimics5.0 medical image processing software, the image threshold was adjusted to 462-2676 HU by the Draw Profile Line and the Thresholding function, and the limit of each part of the lumbar vertebra was more clear. A new mask can be formed using the region growth to form a segmented region on the mask that are not connected to each other. Use the Region Growing feature to roughly extract the various segments of the lumbar region of interest. And the three-dimensional space modeling function of the software is utilized, and the data subjected to the fault image processing is modeled by a three-dimensional model, and the independent three-dimensional surface skeleton model of each vertebral body is established. In order to make the model more real and smooth, the appropriate parameters are set for each model, so that the three-dimensional three-dimensional shape of the bone structure of the thoracolumbar vertebral body is more clearly and intuitively reproduced. The three-dimensional image thus established can be vertically compressed in the software, the left and right translation and the rotation can be performed in a comprehensive manner on the functions of the spine. It is also possible to hide, delete, add, and merge the required functions to obtain different appearance and effect according to the actual situation of the study. The SolidWorks software includes a grid processing wizard and a surface generation wizard function, and the two functions can be used to generate a solid part of a point cloud file of each vertebral body. The processing method comprises the following steps of: performing noise elimination, smoothing, surface fitting and the like on the model, and simultaneously using a sketch function to draw a contour map of the nail rod system, And using the functions of stretching, rotation and the like to obtain the solid model of the nail rod system, and then using the engineering drawing to accurately position the assembly model. The assembly body established in the SolidWorks software is introduced into the HyperMesh software, and the assembly body is meshed with the powerful mesh generation and division function of the HyperMesh software, and the cortical bone is constructed at the same time, the thickness is 1mm, and the division sizes of the tetrahedron mesh are respectively: the waist 3-waist 5 is 2 mm, the thickness 1 is 3 mm, and the nail rod system is 1 mm. According to the anatomical location and morphology, the accessory anatomical structures of the thoracolumbar segment, such as the endplates, the fiber rings, the nucleus pulposus and the articular cartilage, are used to simulate the 7 different ligament structures present between the vertebral bodies, including the anterior longitudinal ligament, the posterior longitudinal ligament, the transverse interspinous ligament, the spinous ligament, the interspinous ligament, The structure of the ligamentum flavum, the joint capsule and the like, as well as the structure of the upper and lower articular processes, the cartilage and the like, is used to obtain a three-dimensional finite element model of the chest 11-waist 3, and the model is composed of a 147064 cell and a 39157 nodes. (4) The effectiveness and accuracy of the verification model: the assignment of the materials in the model is based on the document assignment accepted by the Chinese and foreign medical personnel, and the data parameters for operation and loading are also set according to the latest research results. In this experiment, the mesh is divided by the Hypermesh software with strong grid division function, the quality of the grid is improved, and the C3D4 tetrahedral unit with strong self-adaptive capacity is adopted, and the accurate result can be calculated in the acceptable time. The defect volume was set to 1/5,2/5,3/5,4/5,5/5 of the volume of the prevertebral column. All kinds of loads are applied to the five models fixed and removed in the assembly, and the mechanical analysis, the statistical data and the trend chart of the five models are analyzed. Results: From the stress cloud of the normal vertebral body, we can find that the anterior 2/3 of the vertebral body and the posterior and proximal pedicle of the vertebral endplates of the vertebral body in the vertical state are the stress concentration area of the normal vertebral body, and are radially distributed to the posterior lateral side; the stress of the cortical bone, especially the leading edge of the vertebral body, is higher than that of the cancellous bone; There was a stress concentration around the flexion and extension side as well as the pedicle of the vertebral body when the vertebral body and the lateral flexion and extension movement. In the model of driving the nail rod system,5 upper end plates collapsed (1/5,2/5,3/5,4/5,5/5) of the anterior column of the vertebral body respectively, and the stress distribution in the vertical, anterior and posterior flexion, lateral flexion and left and right rotation can be seen. The stress is also increased correspondingly, and as the vertebral endplates collapse and the volume of the bone defect of the anterior column gradually increases, the stress is gradually concentrated to the inner fixation. After taking out the internal fixation, the stress of the five upper end-plate collapse models showed that with the removal of the internal fixation, the stress was gradually increased with the increase of the volume of the defect. it can be seen from the point chart that, with the increasing of the volume of the defect after the internal fixation is taken out, as the volume of the defect reaches 4/5 of the pre-vertebral column and continues to increase, In group E (4/5 defect group,5/5 defect group, the stress difference of 5/5 defect group) was the largest in 7 working conditions. This means that the load carrying capacity of the injured vertebra is significantly reduced at this time, and the increased concentrated stress will result in the fracture of the anterior column of the injured vertebra. In this case, the internal fixation, the collapse of the injured vertebra is not sufficient to maintain stability, and the increased biomechanical stress has the risk of continued compression or even further fracture. Conclusion: The deformation of the upper end plate of the injured vertebral body is simulated by the finite element method, and the stress change of the injured vertebral body with the change of the volume of the defect is calculated. When the volume of the defect reaches 4/5 of the prevertebral column and continues to increase, the combined stress of the 7 working conditions that the injured vertebra is subjected to is the largest. This means that the load carrying capacity of the injured vertebra is significantly reduced at this time, and the increased concentrated stress will result in the fracture of the anterior column of the injured vertebra. At this time, the internal fixation is taken out, the collapsed injured vertebra is not enough to maintain the stability, the increased biomechanical stress can lead to the risk of continuing to compress or even fracture again, and when the defect volume reaches 3/5 of the front column, the taking out of the internal fixation should be carefully considered, However, this phenomenon and clinical treatment still need to be further studied.
【學(xué)位授予單位】：揚州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：R687.3
本文編號：2500990
[Abstract]:Objective: To establish a finite element model for the biomechanical analysis of the patients with the collapse of the vertebral endplates after the fracture of the thoracolumbar fracture. Methods: (1) Experimental subjects: one of male volunteers was recruited, including medical history, X-ray and other imaging examinations, and there were no other spinal diseases such as spinal deformity, no trauma, and no tumor. (2) Data acquisition equipment: volunteers take the natural state horizontal position, and scan the horizontal thin layer from the Ti1-I3 vertebral body to obtain the horizontal screenshot of 144 corresponding sections. The scanned data is derived in a dicom format and is recorded on an optical disc for processing the image data in the mmoics15.0 medical image processing software. (3) The three-dimensional finite element model of the thoracic and lumbar spine of Ti1-L3 was established: the data was introduced into the Mimics5.0 medical image processing software, the image threshold was adjusted to 462-2676 HU by the Draw Profile Line and the Thresholding function, and the limit of each part of the lumbar vertebra was more clear. A new mask can be formed using the region growth to form a segmented region on the mask that are not connected to each other. Use the Region Growing feature to roughly extract the various segments of the lumbar region of interest. And the three-dimensional space modeling function of the software is utilized, and the data subjected to the fault image processing is modeled by a three-dimensional model, and the independent three-dimensional surface skeleton model of each vertebral body is established. In order to make the model more real and smooth, the appropriate parameters are set for each model, so that the three-dimensional three-dimensional shape of the bone structure of the thoracolumbar vertebral body is more clearly and intuitively reproduced. The three-dimensional image thus established can be vertically compressed in the software, the left and right translation and the rotation can be performed in a comprehensive manner on the functions of the spine. It is also possible to hide, delete, add, and merge the required functions to obtain different appearance and effect according to the actual situation of the study. The SolidWorks software includes a grid processing wizard and a surface generation wizard function, and the two functions can be used to generate a solid part of a point cloud file of each vertebral body. The processing method comprises the following steps of: performing noise elimination, smoothing, surface fitting and the like on the model, and simultaneously using a sketch function to draw a contour map of the nail rod system, And using the functions of stretching, rotation and the like to obtain the solid model of the nail rod system, and then using the engineering drawing to accurately position the assembly model. The assembly body established in the SolidWorks software is introduced into the HyperMesh software, and the assembly body is meshed with the powerful mesh generation and division function of the HyperMesh software, and the cortical bone is constructed at the same time, the thickness is 1mm, and the division sizes of the tetrahedron mesh are respectively: the waist 3-waist 5 is 2 mm, the thickness 1 is 3 mm, and the nail rod system is 1 mm. According to the anatomical location and morphology, the accessory anatomical structures of the thoracolumbar segment, such as the endplates, the fiber rings, the nucleus pulposus and the articular cartilage, are used to simulate the 7 different ligament structures present between the vertebral bodies, including the anterior longitudinal ligament, the posterior longitudinal ligament, the transverse interspinous ligament, the spinous ligament, the interspinous ligament, The structure of the ligamentum flavum, the joint capsule and the like, as well as the structure of the upper and lower articular processes, the cartilage and the like, is used to obtain a three-dimensional finite element model of the chest 11-waist 3, and the model is composed of a 147064 cell and a 39157 nodes. (4) The effectiveness and accuracy of the verification model: the assignment of the materials in the model is based on the document assignment accepted by the Chinese and foreign medical personnel, and the data parameters for operation and loading are also set according to the latest research results. In this experiment, the mesh is divided by the Hypermesh software with strong grid division function, the quality of the grid is improved, and the C3D4 tetrahedral unit with strong self-adaptive capacity is adopted, and the accurate result can be calculated in the acceptable time. The defect volume was set to 1/5,2/5,3/5,4/5,5/5 of the volume of the prevertebral column. All kinds of loads are applied to the five models fixed and removed in the assembly, and the mechanical analysis, the statistical data and the trend chart of the five models are analyzed. Results: From the stress cloud of the normal vertebral body, we can find that the anterior 2/3 of the vertebral body and the posterior and proximal pedicle of the vertebral endplates of the vertebral body in the vertical state are the stress concentration area of the normal vertebral body, and are radially distributed to the posterior lateral side; the stress of the cortical bone, especially the leading edge of the vertebral body, is higher than that of the cancellous bone; There was a stress concentration around the flexion and extension side as well as the pedicle of the vertebral body when the vertebral body and the lateral flexion and extension movement. In the model of driving the nail rod system,5 upper end plates collapsed (1/5,2/5,3/5,4/5,5/5) of the anterior column of the vertebral body respectively, and the stress distribution in the vertical, anterior and posterior flexion, lateral flexion and left and right rotation can be seen. The stress is also increased correspondingly, and as the vertebral endplates collapse and the volume of the bone defect of the anterior column gradually increases, the stress is gradually concentrated to the inner fixation. After taking out the internal fixation, the stress of the five upper end-plate collapse models showed that with the removal of the internal fixation, the stress was gradually increased with the increase of the volume of the defect. it can be seen from the point chart that, with the increasing of the volume of the defect after the internal fixation is taken out, as the volume of the defect reaches 4/5 of the pre-vertebral column and continues to increase, In group E (4/5 defect group,5/5 defect group, the stress difference of 5/5 defect group) was the largest in 7 working conditions. This means that the load carrying capacity of the injured vertebra is significantly reduced at this time, and the increased concentrated stress will result in the fracture of the anterior column of the injured vertebra. In this case, the internal fixation, the collapse of the injured vertebra is not sufficient to maintain stability, and the increased biomechanical stress has the risk of continued compression or even further fracture. Conclusion: The deformation of the upper end plate of the injured vertebral body is simulated by the finite element method, and the stress change of the injured vertebral body with the change of the volume of the defect is calculated. When the volume of the defect reaches 4/5 of the prevertebral column and continues to increase, the combined stress of the 7 working conditions that the injured vertebra is subjected to is the largest. This means that the load carrying capacity of the injured vertebra is significantly reduced at this time, and the increased concentrated stress will result in the fracture of the anterior column of the injured vertebra. At this time, the internal fixation is taken out, the collapsed injured vertebra is not enough to maintain the stability, the increased biomechanical stress can lead to the risk of continuing to compress or even fracture again, and when the defect volume reaches 3/5 of the front column, the taking out of the internal fixation should be carefully considered, However, this phenomenon and clinical treatment still need to be further studied.
【學(xué)位授予單位】：揚州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：R687.3
【參考文獻】
相關(guān)期刊論文 前10條
1 張建新;李玉明;張?zhí)K斌;呂曦;;脊柱前路內(nèi)固定器系統(tǒng)與脊柱后路椎弓根釘棒系統(tǒng)治療腰椎爆裂性骨折的療效比較[J];創(chuàng)傷外科雜志;2016年05期
2 汪建良;許科峰;;脊柱胸腰段釘棒系統(tǒng)后外側(cè)前后一體內(nèi)固定的有限元分析[J];中國組織工程研究;2014年40期
3 陳浩;張錦洪;賀增良;;脊柱胸腰段三維有限元模型的建立與驗證[J];江蘇大學(xué)學(xué)報(醫(yī)學(xué)版);2014年01期
4 沈軍;鄒天明;繆燁;王燁峰;胥正泉;王東來;;決定胸腰椎骨折椎體內(nèi)植骨組織爬行替代的因素[J];中國組織工程研究;2013年53期
5 劉上樓;徐軍;倪卓民;張云慶;周楓;姜雪峰;;經(jīng)胸腰段傷椎單節(jié)段椎弓根螺釘固定后的生物力學(xué)特性[J];中國組織工程研究;2013年39期
6 龔志強;姜曉幸;馮振洲;蔣淳;陳子賢;曹淵武;萬盛成;;腰椎單雙側(cè)椎弓根螺釘固定后的有限元分析比較[J];復(fù)旦學(xué)報(醫(yī)學(xué)版);2013年02期
7 劉治華;管文浩;檀中奇;;基于CT圖像構(gòu)建的腰椎三維有限元模型[J];中國組織工程研究;2012年26期
8 李光燦;李康華;鄭連杰;李靖年;李正維;劉曉凱;李志剛;;全脊柱終板抗壓強度分布規(guī)律的生物力學(xué)研究[J];醫(yī)用生物力學(xué);2011年06期
9 劉鋼;;釘棒系統(tǒng)置入內(nèi)固定治療腰椎骨折的力學(xué)分析[J];中國組織工程研究與臨床康復(fù);2011年43期
10 李欽亮;劉藝;儲朝明;賀雙軍;陳金傳;陳鳴;;傷椎椎弓根置釘治療胸腰椎壓縮性骨折的三維有限元分析[J];中國組織工程研究與臨床康復(fù);2011年39期
，本文編號：2500990
本文鏈接：http://sikaile.net/yixuelunwen/waikelunwen/2500990.html
最近更新
教材專著
