發(fā)布時間：2018-08-18 14:35

【摘要】：研究背景：髖臼骨折(Acetabular Fractures)作為骨盆骨折的一種特殊類型,由于其波及髖關(guān)節(jié)面,屬于關(guān)節(jié)內(nèi)骨折。受傷機(jī)制多為直接暴力引起,臨床上最常見致傷原因為壓砸傷、高處墜落和交通事故。根據(jù)2014年的一項中美髖臼骨折流行病學(xué)對比調(diào)查研究顯示,隨著工業(yè)、建筑業(yè)規(guī)模的不斷擴(kuò)大,機(jī)動車數(shù)量的迅速增加,2005-2012年間,該類骨折的發(fā)生呈逐年增長趨勢,其中青壯年男性是主要受傷人群。隨著世界人口老齡化的加劇,患者的年齡有逐漸增加的趨勢。髖臼周圍解剖結(jié)構(gòu)復(fù)雜,位置深在,手術(shù)難度較大,骨折術(shù)后易發(fā)生異位骨化、創(chuàng)傷性關(guān)節(jié)炎等并發(fā)癥,一直以來是創(chuàng)傷骨科領(lǐng)域研究的重點(diǎn)和難點(diǎn)。在過去的半個世紀(jì),隨著手術(shù)技巧和人們對該類骨折認(rèn)識的不斷提高,針對髖臼骨折,目前臨床上主張手術(shù)治療,尤其對于累及髖臼負(fù)重區(qū)、移位明顯和關(guān)節(jié)內(nèi)存在游離骨折塊的骨折類型,切開復(fù)位內(nèi)固定已經(jīng)成為該類骨折首選治療方案。但是,傳統(tǒng)的切開復(fù)位內(nèi)固定手術(shù)具有失血量大,周圍神經(jīng)血管損傷,切口感染等手術(shù)并發(fā)癥的風(fēng)險。對于無移位或移位不明顯的髖臼骨折類型,近年來有學(xué)者提出在術(shù)中透視輔助下,采用經(jīng)皮拉力螺釘固定骨折的方法。該方法不僅具有顯露范圍小,失血量少,異位骨化發(fā)生率低等優(yōu)點(diǎn),更能夠?qū)崿F(xiàn)患肢早期功能鍛煉,減少臥床時間,有利于獲得滿意的患肢功能恢復(fù)。因此,成為骨盆髖臼骨折微創(chuàng)治療的重要研究方向。髖臼后柱作為髖臼的主要構(gòu)成部分,骨折時常常累及該部位,目前的研究已經(jīng)證明了采用經(jīng)皮逆行拉力螺釘固定髖臼后柱骨折的可行性。國內(nèi)外學(xué)者開展了大量的相關(guān)研究,主要包括后柱釘?shù)赖慕馄蕦W(xué)測量和置釘方法學(xué)的研究。目前,在進(jìn)行經(jīng)皮逆行拉力螺釘固定髖臼后柱骨折操作時,普遍選擇坐骨結(jié)節(jié)作為進(jìn)針點(diǎn),但是由于坐骨結(jié)節(jié)區(qū)域為粗糙弧形骨面,缺乏定位標(biāo)志,選擇理想進(jìn)針點(diǎn)存在困難。且髖臼后柱周圍組織結(jié)構(gòu)復(fù)雜,骨性通道狹長,骨質(zhì)菲薄,置釘不慎則存在螺釘穿出骨板或誤入關(guān)節(jié)的風(fēng)險,造成醫(yī)源性神經(jīng)血管損傷或創(chuàng)傷性關(guān)節(jié)炎的發(fā)生,成為了限制該技術(shù)臨床應(yīng)用的主要原因。針對這一臨床難點(diǎn),有學(xué)者提出了經(jīng)坐骨小切跡置入拉力螺釘?shù)姆椒?認(rèn)為該方法較傳統(tǒng)方式具有定位更準(zhǔn)確,力學(xué)穩(wěn)定性更佳的優(yōu)勢,但是由于實(shí)驗人群和實(shí)驗方法的不同,相關(guān)報道所測量的釘?shù)绤?shù)差異較大,且相關(guān)的內(nèi)固定物生物力學(xué)穩(wěn)定性對比實(shí)驗也未見報道。隨著計算機(jī)技術(shù)的不斷發(fā)展,運(yùn)用三維軟件可以實(shí)現(xiàn)對骨盆的三維重建,精確測量相關(guān)解剖參數(shù),并通過有限元分割、材料賦值,建立相應(yīng)的骨折內(nèi)固定模型,模擬生理狀態(tài),施加應(yīng)力,實(shí)現(xiàn)對骨折內(nèi)固定物生物力學(xué)穩(wěn)定性的評價,具有可重復(fù)性高,節(jié)約成本和真實(shí)可靠的特點(diǎn)。本研究通過以志愿者骨盆CT原始斷層掃描數(shù)據(jù)為材料,選擇兩種臨床有代表性的置釘方案,在測量其釘?shù)澜馄蕯?shù)據(jù)的同時,對其生物力學(xué)穩(wěn)定性進(jìn)行分析比較,以期為臨床應(yīng)用提供參考。目的：1、利用CT影像數(shù)據(jù)建立骨盆三維模型,模擬兩種不同方法置入后柱虛擬圓柱體,測量髖臼后柱骨性通道的相關(guān)解剖參數(shù),對比兩者之間存在的差異,為生物力學(xué)分析提供解剖學(xué)依據(jù)。2、在了解骨盆解剖的基礎(chǔ)上,利用有限元專業(yè)分析軟件,建立骨盆的三維有限元模型,并對該模型的可靠性進(jìn)行分析與驗證,探討其作為生物力學(xué)研究方法的效果。3、在骨盆有限元模型的基礎(chǔ)上,建立起兩種不同的逆行拉力螺釘固定髖臼后柱骨折的模型,模擬生理狀態(tài)對其進(jìn)行相關(guān)生物力學(xué)分析,評價兩種固定方式的生物力學(xué)特點(diǎn),為臨床應(yīng)用提供參考。方法：1、隨機(jī)收集2012年9月-2014年9月在我院行完整盆部CT斷層掃描的成年志愿者的骨盆數(shù)據(jù)32例,男17例,女15例,排除骨質(zhì)病變和解剖異常,掃描層厚0.5mm,將圖像以DICOM格式輸出,導(dǎo)入Mimics 14.1軟件,重建骨盆三維模型,利用軟件自帶的功能,模擬置入髖臼后柱逆行拉力螺釘,測量并獲得髖臼后柱骨性通道的相關(guān)解剖學(xué)參數(shù)。2、骨盆三維有限元模型的建立與驗證：選擇1例健康成年男性志愿者進(jìn)行CT斷層掃描并收集其原始數(shù)據(jù),將數(shù)據(jù)進(jìn)行等容切割,切割厚度0.5mm,以DICOM格式導(dǎo)出,導(dǎo)入Mimics 14.1三維軟件,獲得骨盆三維重建模型,然后應(yīng)用Freefrom、Geomegic Studio等軟件進(jìn)行模型表面光滑和網(wǎng)格化處理等步驟,添加韌帶等骨盆附屬結(jié)構(gòu),建立骨盆實(shí)體三維有限元模型,施加垂直應(yīng)力,觀察骨盆的應(yīng)力和位移云圖,驗證其有效性。3、逆行拉力螺釘固定髖臼后柱骨折有限元模型的建立與生物力學(xué)分析：參考相關(guān)文獻(xiàn),應(yīng)用軟件,模擬后柱骨折線對骨盆有限元模型進(jìn)行截骨,并分別進(jìn)行兩種不同方式的后柱逆行拉力螺釘固定,建立起兩種不同的骨折固定模型,模擬站立位和坐位,對模型進(jìn)行應(yīng)力加載,分別施加大小500N的垂直應(yīng)力,分析兩種不同的模型表現(xiàn)出的生物力學(xué)特性,評價指標(biāo)為骨盆和內(nèi)固定物的應(yīng)力和位移分布云圖,關(guān)節(jié)面骨折線上的位移。4、統(tǒng)計學(xué)分析：所得數(shù)據(jù)使用SPSS19.0軟件進(jìn)行統(tǒng)計學(xué)處理,比較不同性別以及不同內(nèi)固定方案之間存在差異,方法使用獨(dú)立樣本t檢驗和配對樣本t檢驗,α取值0.05,P0.05,數(shù)值結(jié)果采用“均數(shù)±標(biāo)準(zhǔn)差”(x±s)表示。結(jié)果：1、基于CT原始斷層掃描數(shù)據(jù)建立的骨盆三維模型真實(shí)的還原了骨盆復(fù)雜的解剖形態(tài),利用Mimics軟件可以對模型進(jìn)行空間角度、距離的測量。獲得的測量內(nèi)容包括：經(jīng)坐骨結(jié)節(jié)置入的逆行拉力螺釘釘?shù)滥行耘c冠狀面的呈角為(11.69±4.79)°,與矢狀面成角為(10.34±3.60)°；女性與冠狀面成角為(8.36±3.24)°,與矢狀面成角為(12.56±3.48)°。冠狀面(P=0.0040.05)與矢狀面(P=0.0270.05)成角在性別間存在明顯差異。經(jīng)坐骨小切跡置入拉力螺釘男性與冠狀面成角為(39.73±5.69)°,與矢狀面成角為(18.46±5.72)°；女性與冠狀面成角為(40.49±5.06)°,與矢狀面成角為(16.11±6.62)°。冠狀面(P=0.5770.05)與矢狀面(P=0.1320.05)成角在性別間無明顯差異。髖臼后柱拉力螺釘最大直徑為,男性(9.32±1.84)mm,女性(8.51±1.59)mm,男女之間數(shù)據(jù)存在明顯差異(P=0.0230.05),骨性通道平均長度為坐骨結(jié)節(jié)組男性(141.16±10.23)mm,女性(125.72±6.43)mm,坐骨小切跡組男性(115.03±11.19)mm,女性(91.38±9.96)mm,組間與性別之間數(shù)據(jù)存在明顯差異(P=0.0010.05)。2、所建立的骨盆三維有限元模型,完成后的模型自動網(wǎng)格劃分,節(jié)點(diǎn)490227個,網(wǎng)格295806個。模型最大應(yīng)力值為32.45Mpa,位于坐骨大切跡周圍,最大位移值為0.34mm,位于骶髂關(guān)節(jié)處,骨盆模型應(yīng)力分布均勻?qū)ΨQ,與實(shí)際情況相符,可以滿足生物力學(xué)分析需求。3、將拉力螺釘固定髖臼后柱骨折模型分為四組：坐骨結(jié)節(jié)站立位組,坐骨結(jié)節(jié)坐位組,坐骨小切跡站立位組,坐骨小切跡坐位組。施加應(yīng)力,分別得到骨折塊和內(nèi)固定拉力螺釘?shù)膽?yīng)力分布云圖和骨折位移云圖。站立位時拉力螺釘?shù)淖畲髴?yīng)力位于螺釘中部靠近骨折線附近的位置,坐骨結(jié)節(jié)組為6.52Mpa,坐骨小切跡組為6.75Mpa。坐位時應(yīng)力主要集中于螺釘下部,坐骨結(jié)節(jié)組為14.01Mpa,坐骨小切跡組為36.05Mpa。關(guān)節(jié)面骨折線節(jié)點(diǎn)位移均數(shù)為坐骨小切跡站立位組(4.23±1.27)μm。坐骨結(jié)節(jié)站立位組(4.05±1.31)μm,坐骨小切跡坐位組(6.45±0.44)μm,坐骨結(jié)節(jié)坐位組(7.27±0.48)μm,其中坐位時的位移均數(shù)在兩種內(nèi)固定物之間存在統(tǒng)計學(xué)差異(P=0.0030.05)。結(jié)論：1、本研究應(yīng)用Mimics三維軟件和骨盆CT斷層掃描數(shù)據(jù),對骨盆進(jìn)行建模并進(jìn)行三維測量,所得模型仿真度高,相關(guān)測量數(shù)據(jù)精確可靠。利用該模型建立的有限元模型真實(shí)的反映了骨盆生物力學(xué)特性,可以用于相關(guān)生物力學(xué)分析研究。2、對比兩種不同的后柱逆行拉力螺釘固定方法,得出采用經(jīng)坐骨小切跡置釘?shù)姆椒ㄆ涔钦鄱藨?yīng)力與位移較采用經(jīng)坐骨結(jié)節(jié)置釘方法小,提示經(jīng)坐骨小切跡置釘具有一定的生物力學(xué)優(yōu)勢,但具體到臨床應(yīng)用尚需結(jié)合患者的具體情況決定。3、本實(shí)驗的不足之處在于,受限于實(shí)驗條件,測量數(shù)據(jù)樣本數(shù)量較少。運(yùn)用有限元法將模型不同骨質(zhì)均設(shè)置為均勻同質(zhì)的生物材料,但骨盆骨性結(jié)構(gòu)復(fù)雜,其松質(zhì)骨與皮質(zhì)骨密度分布不均,故實(shí)驗結(jié)果與實(shí)際情況必然存在一定差異,且由于髖臼后柱骨折線走行復(fù)雜,該骨折模型無法滿足所有髖臼后柱骨折內(nèi)固定物的生物力學(xué)分析需要。
[Abstract]:BACKGROUND: Acetabular Fractures, as a special type of pelvic fractures, are intra-articular fractures because of their impact on the hip joint surface. Most of the injuries are caused by direct violence. The most common causes of injuries in clinic are crush, fall and traffic accidents. According to an epidemiology of acetabular fractures in China and the United States in 2014 The comparative study shows that with the continuous expansion of industry and construction industry and the rapid increase of the number of motor vehicles, the incidence of such fractures increased year by year from 2005 to 2012, in which young and middle-aged men were the main injured population. In the past half century, with the continuous improvement of surgical techniques and people's understanding of this kind of fracture, the acetabular fracture has been advocated clinically. Open reduction and internal fixation has become the preferred treatment for acetabular fractures, especially those involving the acetabular load-bearing area, with obvious displacement and free fracture fragments in the joint. In recent years, some scholars have proposed to fix acetabular fractures with percutaneous lag screw assisted by intraoperative fluoroscopy. This method not only has the advantages of small exposure range, less blood loss, and low incidence of heterotopic ossification, but also can achieve early functional exercise of affected limbs, reduce bedridden time and is beneficial. The posterior column of the acetabulum, as the main component of the acetabulum, often involves this part of the acetabulum. The present study has proved the feasibility of using percutaneous retrograde lag screw to fix the posterior column of the acetabulum fracture. A large number of related studies, including anatomical measurements of the posterior column canal and methodological studies of screw placement. At present, the ischial tubercle is generally selected as the insertion point in the percutaneous retrograde lag screw fixation of acetabular posterior column fractures. However, because the area of the ischial tubercle is rough and curved, there is no localization mark, the ideal insertion point is chosen. Acetabular posterior column around the complex structure, narrow bone passage, thin bone, improper screw placement, there is a risk of screw penetration or incorrect into the joint, resulting in iatrogenic neurovascular injury or traumatic arthritis, has become the main reason for limiting the clinical application of this technique. A new method of inserting lag screw through ischial small notch was proposed. The method has the advantages of more accurate positioning and better mechanical stability than the traditional method. However, due to the difference between the experimental group and the experimental method, the parameters of the screw path measured by the relevant reports are quite different, and the biomechanical stability of the related internal fixator is compared with the experiment. With the continuous development of computer technology, three-dimensional reconstruction of the pelvis can be achieved by using three-dimensional software, accurate measurement of relevant anatomical parameters, and through finite element segmentation, material assignment, the establishment of the corresponding fracture internal fixation model, simulation of physiological state, stress, the realization of fracture internal fixation biomechanical stability evaluation. Price, repeatability, cost savings and reliability are the characteristics of this study. In order to provide a reference for clinical application, two representative screw placement schemes were selected based on volunteer pelvic CT data. Objective: 1. To establish a three-dimensional model of the pelvis using CT image data, simulate two different methods of implanting the posterior column virtual cylinder, measure the anatomical parameters of the posterior column of acetabulum, compare the differences between the two methods, and provide anatomical basis for biomechanical analysis. 2. On the basis of understanding the pelvic anatomy, use finite element professional points. Three-dimensional finite element model of the pelvis is established, and the reliability of the model is analyzed and validated. The effect of the model as a biomechanical research method is discussed. 3 Based on the finite element model of the pelvis, two different models of retrograde lag screw fixation of acetabular posterior column fracture are established, which simulate the physiological state of the pelvis. Methods: 1. 32 adult volunteers, 17 males and 15 females, who underwent complete pelvic CT scan in our hospital from September 2012 to September 2014, were randomly collected for pelvic data. Bone lesions and anatomical abnormalities were excluded. The scan thickness was 0.5mm. The images were taken as DICO images. M-format output, import Mimics 14.1 software, reconstruct the three-dimensional model of the pelvis, use the functions of the software, simulate the retrograde lag screw placement of the acetabular posterior column, measure and obtain the relevant anatomical parameters of the acetabular posterior column osseous channel. 2. Establishment and verification of the three-dimensional finite element model of the pelvis: A healthy adult male volunteer was selected for CT sectioning. Scanning and collecting the original data, isovolumetric cutting, cutting thickness of 0.5mm, deriving in DICOM format, importing Mimics 14.1 three-dimensional software to obtain the pelvic three-dimensional reconstruction model, then using Freefrom, Geomegic Studio and other software to smooth and mesh the surface of the model, adding ligaments and other pelvic appendages to build bones. Pelvic solid three-dimensional finite element model, applied vertical stress, pelvic stress and displacement nephogram observation, verify its effectiveness. 3, retrograde tension screw fixation acetabular posterior column fracture finite element model and biomechanical analysis: reference to relevant literature, application software, simulation of posterior column fracture line of pelvic finite element model osteotomy, and respectively Two different models of fracture fixation were established by using two different methods of retrograde lag screw fixation of posterior column. The model was loaded with stress in standing and sitting position. The vertical stress of 500 N was applied to the model. The biomechanical characteristics of the two models were analyzed. The evaluation indexes were pelvic and internal fixator stress and internal fixator stress. Distribution nephogram of displacement, displacement on fracture line of articular surface. 4. Statistical analysis: The data were processed by SPSS19.0 software, and the differences between different genders and different internal fixation schemes were compared. Methods The independent sample t test and paired sample t test were used. The values of alpha were 0.05, P 0.05. The numerical results were analyzed by means of "mean + standard deviation". Results: 1. The complex anatomy of the pelvis was restored based on the original CT scan data, and the spatial angle and distance of the pelvis were measured by Mimics software. The angle between the coronal plane and the sagittal plane was (11.69 [4.79] [10.34] [3.60]] and between the coronal plane and the sagittal plane was (8.36 [3.24] [12.56] and (12.56 [3.48]]]] respectively. The angle between the coronal plane (P = 0.0040.05) and the sagittal plane (P = 0.0270.05) was significantly different between the sexes. The angle between the posterior column of acetabulum and the sagittal plane was (18.46 [5.72]], the angle between the females and the coronal plane was (40.49 [5.06]], and the angle between the coronal plane (P = 0.5770.05) and the sagittal plane (P = 0.1320.05). There was no significant difference between the sexes. There was significant difference in the data between groups (P = 0.0230.05). The average length of bone passage was 141.16 (+ 10.23) mm in male, 125.72 (+ 6.43) mm in female, 115.03 (+ 11.19) mm in male and 91.38 (+ 9.96) mm in female. There was significant difference in the data between groups and between sexes (P = 0.0010.05). The three-dimensional finite element model of pelvis established. The model has 490227 nodes and 295806 grids. The maximum stress value of the model is 32.45 Mpa, and the maximum displacement value is 0.34 mm. It is located at the sacroiliac joint. The stress distribution of the pelvic model is uniform and symmetrical. It can meet the needs of biomechanical analysis. The posterior column fracture model was divided into four groups: ischial tubercle standing position group, ischial tubercle sitting position group, ischial small notch standing position group and ischial small notch sitting position group. In sitting position, the stress was mainly concentrated in the lower part of the screw, 14.01 Mpa in the sciatic tubercle group and 36.05 Mpa in the small sciatic notch group. The mean displacement in sitting position was significantly different between the two internal fixations (P = 0.0030.05). Conclusion: 1. In this study, the pelvis was modeled and measured by Mimics 3D software and CT scan data. The finite element model established by this model can reflect the biomechanical characteristics of the pelvis, and can be used for the biomechanical analysis. 2. Comparing the two different methods of retrograde lag screw fixation, the stress at the fracture end and the stress at the fracture end of the pelvis can be obtained by the method of small notch screw placement through the ischium. The displacement is smaller than that of trans-ischial tubercle nailing, suggesting that trans-ischial small notch nailing has certain biomechanical advantages, but its clinical application still needs to be decided according to the specific conditions of patients. 3. The deficiency of this experiment is that limited by experimental conditions, the number of measured data samples is less. Finite element method is used to model different bone. All of them are homogeneous biomaterials, but the pelvic bone structure is complex, and the distribution of cancellous bone and cortical bone mineral density is uneven. Therefore, there must be some differences between the experimental results and the actual situation.
【學(xué)位授予單位】：南方醫(yī)科大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：R687.3

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本文編號：2189775