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1.
目的:探讨人工全膝关节假体旋转稳定性与髌骨轨迹的关系,阐明CT技术检测假体轴向旋转稳定性的优越性。方法:28例施行人工全膝关节置换术后出现单纯髌股关节并发症的患者进行膝关节轴位CT扫描,选择股骨髁上轴和胫骨结节作为CT扫描的参考标志来测量股骨假体和胫骨假体的旋转角度,分析旋转稳定性与髌股关节并发症的相关性。结果:研究组患者的全关节假体(股骨假体 胫骨假体)旋转角度存在过度内旋,内旋的角度与髌股关节并发症的严重程度存在对应关系。轻度(1°~4°)内旋对应髌骨轨迹不良髌骨翘起,中度(3°~9°)内旋对应髌骨半脱位,重度(6°~18°)内旋对应早期的髌骨脱位和晚期的髌骨假体失败。结论:假体的内旋可能是人工膝关节置换手术后出现髌股关节并发症的重要原因,使用CT技术可以确定人工关节假体是否存在旋转不良,提示进行单一假体翻修或全关节翻修手术。  相似文献   

2.
目的建立健康成年人膝关节三维有限元模型并进行验证,在此基础上建立模拟后交叉韧带单束重建术的股骨、胫骨隧道和移植物模型,为进一步分析奠定基础。方法以MRI作为数据源,运用医学制图软件Mimics,逆向工程软件Geomagic studio、Solidworks及有限元分析软件Abaqus,参考大量有关实验的文献报道,建立所需三维有限元模型。验证模型:模拟膝关节在屈曲0°情况下,对股骨施加后向134 N集中力,得出胫骨股骨相对位移及主要韧带受力分布与已报道文献进行比较;模拟膝关节屈曲0°情况下,加载垂直方向395 N集中力(单腿站立时下肢受力),得出软骨及半月板von Mises应力并与已报道文献进行比较。结果建立的膝关节三维有限元模型包括股骨下段、胫腓骨上段、髌骨、股骨软骨、胫骨软骨、髌骨软骨、髌韧带、内外侧半月板、前后交叉韧带、内外侧副韧带,几何形状良好。模型验证:股骨相对胫骨前后、远近及内外方向上位移分别为4.52 mm、0.35 mm和1.12 mm,此时韧带应力主要分布在前交叉韧带股骨附着处和体部且股骨附着处最大,与类似实验报道结果一致,且与临床结论前交叉韧带主要限制胫骨前移、在股骨附着处易发生断裂一致;半月板承担主要应力且内侧大于外侧,主要分布在内缘,最大应力值为1.65 MPa,其次胫骨软骨最大应力为1.05 MPa,股骨软骨应力最小,主要受力部位在内侧,为0.78 MPa;与已报道文献及尸体解剖力学实验结果一致,验证了该模型的有效性,在此基础上模拟建立后交叉韧带单束解剖重建股骨、胫骨隧道和移植物模型,基本可以满足有限元分析的需要。结论采用MRI图像建立膝关节三维有限元模型切实可靠,能很好地模拟膝关节解剖结构及后交叉韧带重建术中的股骨、胫骨隧道并满足生物力学的研究。  相似文献   

3.
背景:三维有限元分析在骨科中被广泛应用,在膝关节屈曲运动中的研究不多。目的:对膝关节屈曲运动的生物力学特性进行三维有限元分析。方法:建立膝关节的三维有限元模型以及膝关节屈曲30°,60°以及120°时的三维有限元模型,分析膝关节不同屈曲位股骨前移情况、股骨内移情况、胫骨内旋情况和胫骨内翻情况。结果与结论:(1)股骨前移:在膝关节屈曲30°,60°和120°时股骨均出现后移,膝关节屈曲60°时的股骨后移值大于屈曲30°和屈曲120°(P0.05);膝关节屈曲120°股骨后移值大于屈曲30°,但差异无显著性意义(P0.05);(2)股骨内移:在膝关节屈曲30°时股骨外移,在膝关节屈曲120°时膝关节内移,膝关节屈曲120°时股骨内移值明显大于屈曲30°和屈曲60°时(P0.05);膝关节屈曲30°和屈曲60°时外移值比较差异无显著性意义(P0.05);(3)胫骨内旋:在膝关节屈曲30°,60°和120°时胫骨均出现内旋,3者比较差异均无显著性意义(P0.05);(4)胫骨内翻:在膝关节屈曲30°,60°和120°时胫骨均出现内翻,其中屈曲120°时胫骨内翻不明显,膝关节屈曲60°时胫骨内翻度数最大,明显高于屈曲120°时(P0.05);膝关节屈曲30°时胫骨内翻度数大于屈曲120°时,但差异无显著性意义(P0.05);(5)结果表明,膝关节在屈曲60°时股骨后移最明显,膝关节屈曲120°时股骨内移值最大,膝关节屈曲30°和屈曲120°时胫骨内旋明显,膝关节屈曲60°时胫骨明显内翻。  相似文献   

4.
目的 分析全身关节过度活动(generalized joint hypermobility, GJH)女性患者与健康女性在跳深着陆中膝关节软骨、半月板von Mises应力分布差异。方法 采集女性GJH患者与女性健康受试者在跳深着陆缓冲阶段垂直地面反作用力(vertical ground reaction force, VGRF)峰值时刻的膝关节运动学与地面反作用力特征,通过逆动力学计算膝关节反作用力,并将膝关节沿股骨长轴方向的合力作为载荷;基于1名女性膝关节三维有限元模型,分别对2组受试者跳深着陆过程进行数值仿真,计算膝关节软骨与半月板von Mises应力及应力分布。结果 在跳深着陆VGRF峰值时刻,GJH组和对照组膝关节屈曲、外翻角度具有统计学意义(P<0.05)。相比于对照组,GJH组膝关节屈曲角度降低、外翻角度增加;在跳深着陆中,GJH组膝关节内部承受应力更大且胫股关节内、外侧室负重区应力分布不均衡,其股骨软骨外侧髁外侧、外侧胫骨软骨前部/中部外侧以及外侧半月板前角、体部外侧缘为应力集中部位。结论 女性GJH患者因膝关节活动范围增大、关节囊松弛,导致在跳跃类项目中膝关节...  相似文献   

5.
目的采用有限元方法比较前交叉韧带(anterior cruciate ligament,ACL)完整与缺失的骨关节炎患者单髁关节置换(unicompartmental knee arthroplasty,UKA)术后膝关节生物力学特性,分析ACL缺失对膝关节单髁置换术后的运动和应力的影响。方法根据膝关节CT、MRI图像,建立有限元模型。采用逆向工程技术重建活动衬垫单髁假体,加载入该正常膝关节三维有限元模型。在不同屈膝角度(0°、30°、60°、90°、120°)加载载荷,观察在ACL完整(ACL-intact,ACLI)和缺失(ACL-deficiency,ACLD)情况下,膝关节的最大接触压和位移程度。结果 UKA-ACLI与UKA-ACLD模型在膝关节屈膝各角度,各部位(外侧股骨软骨、胫骨软骨、半月板、股骨假体、胫骨假体、衬垫)最大应力无明显差异,ACLD模型在膝关节屈膝0°和30°位前后位移明显大于ACLI模型,在膝关节屈膝0°位股骨相对内旋减小,在膝关节屈膝30°位股骨相对外旋增加。结论标准位置假体植入情况下,ACL缺失并不会导致UKA术后应力异常增大,会导致在膝关节伸直位时位移增加。  相似文献   

6.
背景:髌股韧带重建有多种手术方式,其中股骨止点选取对手术实施影响较大,目前针对股骨止点的选取有多种方式,但无定论。目的:通过三维有限元软件分析膝关节不同屈曲状态下内侧髌股韧带(MPFL)股骨重建止点位置改变对髌股关节应力的影响,从而选择出合理准确的股骨重建止点。方法:获取成年人正常膝关节CT数据,导入Mimics、Geomagic及Soildworks软件进行提取模具、添加韧带,其中韧带的股骨止点选择分别为股骨内上髁与内收肌结节连线的中点、股骨内上髁、内收肌结节、股骨髁间窝顶部向内髁投射点和内收肌结节下10 mm,再将添加韧带后的模具导入机械软件Ansys,对不同股骨止点重建后髌股关节应力进行生物力学的有限元分析。结果与结论:(1)在膝关节屈曲0°和30°时,选取任一股骨止点产生的髌股关节应力大于其他屈曲角度(60°,90°,120°);无论采取哪种位点作为股骨端止点,当膝关节屈曲超过30°时,髌股关节间的接触应力大小基本无差别;(2)在膝关节屈曲0°和30°时,以内收肌结节为止点的髌股接触压力最大,以股骨内上髁与内收肌结节连线的中点为止点的接触力最小;在膝关节屈曲30°时,股骨内上髁...  相似文献   

7.
目的建立膝关节有限元模型,研究正常及软骨硬化情况下膝关节的应力、应变变化,为临床治疗膝关节骨性关节炎提供参考。方法通过Mimics、ANSYS等软件结合正常膝关节CT扫描图像数据,建立膝关节三维有限元模型,并施加350 N压力载荷,设定软骨硬化前后相关的材料参数,分析膝关节主要组织的应力、应变改变情况。结果膝关节股骨远端软骨硬化后,关节软骨的减震和传递负荷等作用基本消失;股骨应力、应变变化量最大,受力分布极不均匀,股骨前端应力、应变较内、外侧髁明显,整体受力也有明显增加;半月板的应力、应变值最大。结论长期的软骨破坏会影响关节软骨营养代谢,导致骨性关节炎疾病进一步恶化。研究结果可以较好阐释骨性关节炎发病过程和机理,同时为建立参数化研究系统提供相关数据。  相似文献   

8.
目的 总结人工全膝关节置换(total knee arthroplasty,TKA)术中,纠正髌股关节轨迹不良的方法及效果。 方法 2012年6月-2014 年12 月,对52例58膝TKA术中出现髌骨向外侧脱位倾向髌股关节轨迹不良的患者,针对发生原因,通过单纯调整髌骨内、外侧支持带张力,髌骨修整成形或调整胫骨假体位置等方法,或者联合应用上述两种或两种以上方法进行纠正。 结果 术中无拇指试验髌股关节轨迹恢复正常,术后髌骨未出现向外脱位倾向。术后切口均Ⅰ期愈合,2例因外翻明显,术中外侧支持带松解范围较大,术后出现关节积血,经对症处理后好转,无其他并发症发生。所有患者术后均获随访,随访时间 17-47个月,平均32个月。膝关节内、外翻畸形均获得矫正,4例残留 5-10°(平均8°)左右的屈曲畸形。随访末期KSS评分78-89分,平均84分,膝关节KSS功能评分为82-91分,平均86分。术后至随访期末X线片均显示人工关节位置正常,无松动及感染迹象。 结论 TKA术中出现髌股关节轨迹不良时,通过单纯调整髌骨内、外侧支持带张力,髌骨修整成形或调整胫骨假体等方法,或者联合应用上述两种或两种以上方法等进行调整,是处理髌股轨迹不良的有效方法,有利于术后膝关节的功能恢复。  相似文献   

9.
近年来利用数字三维模型对人体全膝关节进行生物力学分析在国内外迅速发展,但是缺乏完整精细的膝关节有限元模型;同时对所建立模型的验证也比较单一,仅从韧带或者软骨受力单方面进行有效性的验证,导致模型的实用性和广泛性受到限制。目的以一种创新、高效的方法三维重建精细人体膝关节有限元模型,包括股骨、胫骨、髌骨、腓骨、股骨软骨、胫骨软骨、髌骨软骨、腓骨软骨、半月板、交叉韧带、侧韧带、髌韧带等组织结构,并对整体模型有效验证。方法利用CT和MRI医学影像,使用Mimics、3-Matic、Geomagic、Solidworks、Abaqus软件获得完整、精细的人体膝关节模型;在内外髁中点施加1 000 N竖直向下载荷,分析膝关节内外间室的力学分布及软骨的力学响应;以胫骨平台髁间隆起为参考施加134 N前向推力,模拟临床中的抽屉实验(ADT),获取各韧带组织的生物力学响应,并与现有人体实验及模型对比。结果 1 000 N载荷下,股骨软骨最大Mises应力值为2.514 MPa,半月板最大Miese应力值为7.693 MPa,胫骨软骨最大Mises应力值为1.848 MPa,均分布于膝关节的内侧;内外侧软骨接触面积分别为476.080 8 mm~2和338.446 8 mm~2;内外腔室分别承担总载荷的60.57%和39.43%。134 N载荷下,胫骨平台前端的位移量为5.687 mm;前十字交叉韧带(ACL)最大Mises应力值为28.030 MPa,后十字交叉韧带(PCL)最大Mises应力值为16.730 MPa,内侧副韧带(MCL)最大Mises应力值为4.511 MPa,外科韧带(LCL)最大Mises应力值为3.751 MPa;交叉韧带与股骨止点的最大Mises应力值为15.270 MPa。结论建立的精细膝关节三维模型很好地重塑了人体膝关节相关生物力学特性;该精细膝关节模型仿真结果与现有实验数据非常接近,证明了模型的有效性;完整、有效的精细全膝关节有限元模型将为植入物手术、人体运动分析、康复研究等打下基础。  相似文献   

10.
人体膝关节动态有限元模型及其在TKR中的应用   总被引:2,自引:0,他引:2  
目的 研究膝关节高屈曲活动下运动和应力等的动态特征。为膝关节生物摩擦学研究提供相对运动和应力分布等生物力学数据 方法 建立包括人体主要骨与软组织的全膝关节置换前后的膝关节的动态有限元模型,对天然及全膝置换后膝关节下蹲运动和接触应力分布进行分析,并与相应的尸体实验的结果进行验证分析。结果 通过有限元分析,获得高屈曲膝关节的三维相对运动参数,胫股关节和髌股关节的接触位置和应力等动态力学参数。有限元分析结果表明,分别在膝关节过伸和高屈曲时,在胫骨高分子聚乙烯平台的胫骨平台轮柱和平台前部的交界处、胫骨平台内后方和轮柱后部三个区域发生较高的接触应力。这些也正是假体发生较高磨损率的区域 结论 所建立的有限元模型能够对于膝关节下蹲动作的运动、接触等力学行为进行评估,为临床膝关节全膝置换术、膝关节假体的摩擦学研究及其膝关节假体设计提供有力的分析工具。  相似文献   

11.
Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc2 (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.  相似文献   

12.
Renal dysplasia and asplenia in two sibs   总被引:2,自引:0,他引:2  
A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.  相似文献   

13.
About 1900, modern food selection and processing caused widespread epidemics of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a panhypovitaminosis B, i.e., a mixture of substrate beriberi and substrate pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse endemic disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for primates. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.  相似文献   

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15.
Newton H 《Medical history》2011,55(2):153-182
Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.  相似文献   

16.
Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.  相似文献   

17.
HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.  相似文献   

18.
The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.  相似文献   

19.
Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.  相似文献   

20.
Zusammenfassung Der Einfluß von verschiedenen Nahrungsmitteln auf Methoden zur Bestimmung von Adrenalin (AD), Noradrenalin (NA), Vanillinmandelsäure (VMS), Metanephrinen (MN), Homovanillinsäure (HVS) und 5-Hydroxyindolessigsäure (5-HIE) im 24 h-Harn zur Diagnose des Phäochromozytoms bzw. Karzinoid-Syndroms wurde untersucht. Die in die Untersuchung einbezogenen Nahrungsmittel waren: Tee, Kaffee, Mandeln, Ananas, Käse, Walnüsse, Vanillepudding, Bananen, Tomaten und Milchschokolade. Außerdem wurde der Einfluß des Zigarettenrauchens auf die Bestimmung von AD, NA, VMS und MN untersucht.Walnüsse führten zu einer starken Erhöhung der 5-HIE-Ausscheidung. Bananen erhöhten die Ausscheidung von AD, NA, VMS, MN und 5-HIE. Kaffee und Ananas bewirkten eine geringe Zunahme der MN-Werte. Rauchen von 20–30 Zigaretten/Tag beeinflußte keine der vier Variablen.Wenn die beschriebenen Methoden benutzt werden, sollte lediglich auf den Verzehr von Bananen und Walnüssen vor und während der Harnsammelperioden verzichtet werden, da die oberen Normgrenzen im Harn überschritten werden könnten. Ein Verzicht auf Kaffee und Ananas in normalen Mengen ist nicht erforderlich. Es besteht kein Anlaß, weiterhin die bisherigen umfangreichen Restriktionen der übrigen Nahrungsmittel beizubehalten.  相似文献   

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