股骨头坏死有限元模型的建立

背景：股骨头坏死有限元分析法已经被许多研究者应用,但作为分析的数字模型还存在几何以及物理相似性不够等不足。 目的：借助股骨头坏死患者的CT扫描图片建立更加逼真的股骨头坏死有限元模型。 方法：将以各向同性扫描所得的层厚0.625 mm股骨头坏死髋关节连续断层142层Dicom格式CT图像,直接读入Mimics后界定骨组织阈值、提取各层面轮廓线、图像边缘分割、选择性编辑及补洞处理,去除冗余数据,三维化处理后获得股骨头坏死三维几何面网格模型,将其保存为后缀名.lis的Ansys文件,直接导入Ansys有限元分析软件进行体网格划分,再将体网格转入Mimics根据CT值给予赋值,再次导入Ansys 生成有限元模型。 结果与结论：快捷建立了外形逼真、计算精确的股骨头坏死三维有限元模型。提示应用精细CT扫描技术,Mimics软件根据CT值直接赋值使股骨头坏死三维有限元模型的建立更加快捷、精确。     

个体股骨头坏死三维有限元模型的建立与应用

同时基于个体股骨头坏死患者的X-ray、CT和MRI图像,采用图像配准和融合技术对包含坏死股骨头的髋关节进行三维重建,获取具有高度几何相似性的三维有限元网格模型。选择1例中年女性股骨头坏死患者,分别获取X-ray、CT和MRI三套图像,采用Mimics 13.1和Pro/E 5.1软件分别基于这三套数据建立相关三维实体模型,经图像投影转换后,确定图像之间的匹配点,进行二维图像配准,配准后对成功融合的图像进行三维有限元网格模型显示。建立了具有良好几何相似性的髋关节三维有限元网格模型,包括正常皮质骨、松质骨、关节软骨和股骨头坏死区、断裂骨小梁等六部份,较真实地反映了包含坏死股骨头的髋关节的形态特征及毗邻关系,为进一步的生物力学分析和手术模拟提供了较理想的研究平台。     

基于CT灰度值赋值的股骨头坏死有限元模型对比

文题释义： CT灰度值赋值：此赋值法利用CT灰度的不同,将组织划分为不同的等级材料,利用数学公式将CT灰度值与弹性模量进行转换运算,将不同骨组织材料进行相应赋值,能够较真实的体现骨组织内部的复杂情况,使模型更加准确。 股骨头坏死应力集中：正常股骨头内应力延压力性骨小梁均匀分布在股骨头内,坚硬的股骨距承受大部分应力。股骨头坏死的应力因坏死区骨小梁的断裂、硬化带及肉芽带的形成无法均匀传导下行,股骨头负重区、坏死区应力分布不均匀出现多个应力集中区域,与正常股骨头不同的是,应力分散于股骨颈内外侧。 背景：目前研究股骨头有限元模型多采用单例或较少样本建模用于特定的生物力学研究,对于模型稳定性研究不多。 目的：以正常股骨头和股骨头坏死建模进行多样本的模型对照,通过应力分布规律和力学参数的对比,分析模型的准确性和稳定性,为股骨头坏死塌陷防治提供力学基础。 方法：选择20髋经1年非手术治疗稳定未塌陷的股骨头为实验组,20髋单侧股骨头坏死患者的健侧设为正常组。采集股骨头CT数据分别建立有限元模型,观察正常股骨头与股骨头坏死应力分布、股骨头负重区最大等效应力与最大总形变量,对比并统计分析。研究方案经中国中医科学院望京医院医学伦理委员会批准,患者签署知情同意书。 结果与结论：①建立了正常股骨近端、无坏死股骨近端和坏死骨有限元模型,单元数和节点数分别为       502 568±114 196、692 608±154 678,449 954±125 824、623 311±171 401,19 133±13 167、27 577± 19 131;②模拟单足站立位进行载荷设定的云图显示：当施以体质量2.5倍压强作用于股骨头负重区表面时,正常股骨头负重区表面应力均匀,应力延压力性骨小梁均匀分布在股骨头内,股骨距承受大部分应力;股骨头坏死负重区表面及坏死区出现应力集中区域,头内应力分散于股骨头颈交界,股骨颈内外侧应力相当,且股骨头坏死产生的形变多于正常股骨头;③股骨头坏死与正常股骨头的负重区最大总形变量分别为(4.14±1.31),(1.36±0.22) mm,最大等效应力分别为(1.94±0.77),(0.75±0.19)MPa,差异有统计学意义(P < 0.05),且两组数据偏于集中,模型稳定性较好。通过多样本的正常股骨头与股骨头坏死比较,证明了基于CT灰度值直接赋值反映了股骨头坏死的实际力学特性,具有较好的准确性和稳定性。ORCID: 0000-0001-5227-532X(薛志鹏);0000-0003-0831-1201(陈卫衡) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

多孔钽金属置入治疗早期股骨头坏死的研究与应用现状

BACKGROUND: Porous tantalum rod implantation is a relatively new technique that has been applied to patients with early-stage osteonecrosis of the femoral head, but its efficacy is mixed. OBJECTIVE: To review the etiology and pathogenesis of osteonecrosis of the femoral head and the latest research progress of porous tantalum rod implantation. METHODS: A computer-based search of PubMed and CNKI database was performed for articles related to the pathogenesis of osteonecrosis of the femoral head and porous tantalum rod implantation published from 1985 to 2015. The key words were “osteonecrosis of the femoral head, etiology, porous tantalum rod, tissue engineering, nanomaterials, bone marrow mesenchymal stem cells” in Chinese and English in the title and abstract. Finally, 67 articles were included in result analysis. RESULTS AND CONCLUSION: The porous tantalum rod is considered effective for early-stage osteonecrosis of the femoral head patients in short term. More recently, the porous tantalum rod implantation combined with other therapies, such as stem cell transplantation, has developed for long-term reserving the hip in early-stage osteonecrosis of the femoral head. Therefore, we need further clinical trials for long-term follow-up to give a final clinical and socioeconomic assessment of porous tantalum rod implantation. Moreover, the most effective approach and position of porous tantalum rod implantation have not been reported until now.       

股骨头坏死中松质骨微观力学特性的演变规律

目的采用结合显微CT和显微有限元分析方法,即基于显微CT图像建立三维有限元模型并进行数值模拟仿真分析,无创研究不同分期的坏死股骨头松质骨的微结构和微观力学性能,以期了解在股骨头坏死的发展过程中,松质骨微结构和微观力学特性的变化规律,为临床预测股骨头坏死提供理论基础。方法采集10例股骨头坏死患者的股骨头标本的显微CT图像,按照国际骨循环研究学会分期标准分为Ⅱ期样本3例,Ⅲ期3例,Ⅳ期4例。将图像中骨组织进行阈值分割,分区域建立坏死区、侧向区、硬化区和远端区的松质骨块三维有限元模型(边长8 mm),并根据CT值赋予非均匀材料属性。利用ImageJ软件中的BoneJ插件通过识别显微CT组图像,计算测量各区域松质骨的微结构参数,包括骨体积分数、骨小梁厚度、骨小梁间隙、结构模型指数。对松质骨块施加表观应变为1%的压缩载荷,计算骨组织应力和松质骨表观刚度等参数,对比分析各分期、各分区结果。结果在松质骨微结构方面,Ⅳ期较Ⅱ期的股骨头内部硬化区和坏死区的变化最为明显,硬化区的骨体积分数不断上升,骨小梁间隙下降,结构模型指数减小,而坏死区域与之相反;在骨组织微观受力方面,Ⅱ期到Ⅲ期坏死区域的应力并没有明显变化,而硬化区域随着分期增加应力不断上升,侧向区的应力不断下降。表观刚度变化与应力变化一致。结论随着股骨头坏死程度的加剧,硬化区的松质骨微结构和力学性能变化最大,应作为临床早期诊断中重点关注的区域。此外,微结构参数并不能准确体现松质骨的力学行为,而股骨头塌陷最终取决于其力学特性,因此结合有限元分析方法可更加全面了解股骨头坏死的微观力学演变规律。     

带血管蒂大转子骨瓣联合植骨治疗股骨头坏死

背景：由显微外科技术在股骨头坏死治疗的运用中发展而来的带血管蒂大转子骨瓣联合植骨为治疗中青年股骨头缺血性坏死的主要方法之一。 目的：通过回顾及分析对于大转子骨瓣移植治疗股骨头缺血性坏死的相关临床及基础研究,从不同层面对大转子骨瓣移植术的研究进行探讨。 方法：以“Osteonecrosis Femoral Head、greater trochanter bone flap”或“Osteonecrosis Femoral Head、 bone flap”或“Osteonecrosis Femoral Head、 finite element analysis”为检索词,检索pubmed数据库(1972年1月至2011年10月);以“股骨头坏死、大转子骨瓣”为检索词,检索CNKI数据库(1979年1月至2011年10月)。选择以大转子骨瓣移植治疗股骨头坏死相关,同一领域文献则选择近期发表或发表在权威杂志文章。根据纳入标准共46篇文章进行综述。 结果与结论：关于目前较常用的病灶清除+带旋股外侧动脉横支大转子骨瓣联合打压植骨+游离髂骨瓣植骨治疗股骨头缺血性坏死报道甚少,此术式结合了皮质骨的生物力学优势,同时又有带旋股外侧动脉横支大转子骨瓣加松质骨粒提供良好的血供环境,能很好的解决血供与力学重建的平衡性,达到股骨头的生理重建。     

股骨头缺血性坏死骨瓣移植过程的有限元模拟

基于临床上的一例股骨头三期缺血性坏死患者的单侧CT图像数据，建立了股骨近端的三维有限元模型，包括：正常模型、坏死模型和修复模型。并基于医学OF图像数据，分别对三种有限元模型赋予材料性质。最后应用有限元软件，对股骨头缺血性坏死骨瓣移植手术过程进行了数值模拟。分析结果表明，切除掉坏死区域后，股骨头近端的位移及应力值均增加较大，而采用骨瓣移植手术，可以有效地减少股骨近端的位移及应力值，使其更接近正常状态。说明了该手术方法安全可靠并行之有效。     

三维重建及有限元分析预测股骨头坏死塌陷

通过三维重建技术对坏死股骨头的MRI影像进行重构，获得坏死股骨头的三维几何模型，并由几何模型测量得到股骨头及坏死病灶的体积；同时进行临床实验获得真实坏死股骨头的体积数据。通过对38例患者股骨头的计算机模型和数据与临床实验数据的统计分析，讨论了股骨头坏死病灶大小和部位与股骨头塌陷的关系。然后根据股骨头的坏死区域与所受载荷大小不同，共进行了15组的股骨头受力有限元分析，对坏死股骨头的塌陷情况作了验证。结果表明，本研究提供了一种有效的方法，指导临床选择最佳的治疗方案。     

钽金属棒置入修复股骨头坏死的三维有限元分析

BACKGROUND: Core decompression and tantalum rod implantation after core decompression are common methods to repair early and middle stages of necrosis of femoral head, can effectively control and even reverse the progress of necrosis of the femoral head. Comparison of mechanical support and curative effect of femoral head after operation deserves further investigation. OBJECTIVE: To explore the effect of core decompression on mechanical pulp femoral head support by using the finite element analysis and the advantages of tantalum implant treatment in the repair of avascular necrosis of the femoral head.  METHODS: The right femur of healthy adults was chosen as the research object, and CT scanning was conducted to get the images of cross-sections. The images were then inputted into computer to get contour of femur and rebuild three-dimensional model. Distal end of femur was completely fixed, the angle of the top of femoral head and the femoral shaft was 25°, and 570 N pressure on the femoral head was applied according to the three-dimensional space distribution of femur force under physiological state. Three-dimensional finite element models were calculated to get the collapse values in different necrotic areas of the femoral head before and after different repair methods. RESULTS AND CONCLUSION: After core decompression, collapse values were apparently increased, especially in the weight-bearing area. With increased range of necrosis, collapse values also increased. After core decompression, collapse values decreased obviously after porous tantalum rod implantation. Although core decompression could remove dead bone, decompression itself further reduced the mechanical properties of the femoral head and changed the original femoral head support. On the basis of core decompression, porous tantalum rod provided safe and effective mechanical support for femoral head and subchondral bone plate, could effectively prevent collapse and provide conditions for the restoration of bone tissue.      

骨质疏松股骨转子间不稳定型骨折人工股骨头置换的三维有限元应力分析

BACKGROUND: Artificial femoral head replacement provides a new idea for the repair of unstable intertrochanteric fracture. Artificial prosthesis replacement may affect original femoral biomechanical stability and lead to a variety of adverse consequences.  OBJECTIVE: To analyze the stress distribution of femoral head replacement in the treatment of unstable femoral intertrochanteric fractures with three-dimensional finite element analysis. METHODS: One male old volunteer was randomly selected from population who underwent health examination. The left femur was scanned with spiral CT, and the three-dimensional finite element models of the human femur and prosthesis were established. The three-dimensional finite element model was used to simulate the actual working conditions of human climbing stairs, and the stress distribution of the bone channels around the surface of the femur and the prosthesis was analyzed with three-dimensional finite element analysis. RESULTS AND CONCLUSION: Under normal condition, the stress of the human femur was in a consistent state. Stress changed gradually from the proximal end to the distal end. The stress of the prosthesis was concentrated in the middle section. The prosthesis of inner stress distribution was analyzed to obtain stress distribution of prosthesis and femur cancellous bone interface. The analysis found that stress change trend was consistent. The results suggest that artificial femoral head replacement does not have a significant effect on the overall stress distribution of the human femur, and the overall stress distribution does not change, and the maximum stress region is located in the middle of the whole femur. After the reconstruction, the stress concentration of the femur is not observed.        

Effect of the stiffness of bone substitutes on the biomechanical behaviour of femur for core decompression

Core decompression is the most common procedure for treatment of the early stages of osteonecrosis of the femoral head. The purpose of this study was to compare the biomechanical performance of four different bone graft substitutes combined with core decompression. Subject-specific finite element models generated from computed tomography (CT) scan data were used for a comprehensive analysis. Two different contact conditions were simulated representing states of osseointegration at the interface. Our results showed that the use of a low-stiffness bone substitute did not increase the risk of femoral fracture in the early postoperative phase, but resulted in less micromotion and interfacial stresses than high-stiffness bone substitutes.     

酒精性股骨头坏死竞争性内源RNA网络及潜在生物标志物的综合分析

背景:酒精性股骨头坏死与饮酒具有高度的相关性,然而其具体发病机制尚不明确且存在一定的个体差异.目的:构建酒精性股骨头坏死的基因网络图谱,进一步探索酒精性股骨头坏死的潜在发病机制.方法:从广西中医药大学第一附属医院骨二科招募3例酒精性股骨头坏死患者和3名健康志愿者,通过对其外周血进行基因测序筛选具有差异表达的mRNA和l...     

步幅大小及髋关节外展角度对坏死股骨头影响的三维有限元分析*

背景：目前对于日常生活中步幅及髋关节外展角度大小是否会对坏死股骨头影响认识不多,也缺乏相关的实验研究。 目的：应用三维有限元方法分析步幅大小及髋关节外展角度对坏死股骨头应力分布的影响。 方法：选取1例男性ARCO Ⅱ期股骨头坏死患者行股骨近段螺旋CT扫描,应用专业医学建模软件MIMICS及HYPERMESH建立三维有限元模型。设置边界条件和加载条件,应用有限元分析软件ANSYS执行计算。 结果与结论：随着步幅的加大(0~60°),外展角度增加(0~10°),股骨近段应力分布改变最大应力值逐渐增大,提示步幅及髋关节外展角度的大小能够影响股骨头应力分布,股骨头坏死患者日常治疗生活及功能练习时应减小步幅及外展角。关键词：步幅;股骨头坏死;三维;有限元;外展角 doi:10.3969/j.issn.1673-8225.2012.17.004     

股骨头缺血性坏死塌陷预测的生物力学研究

目的：探索不同部位囊性变对股骨头缺血性坏死的生物力学影响，为预测股骨头的塌陷和指导临床治疗方法的选择提供基础。方法：取新鲜股骨上段标本，行螺旋CT断层扫描，所得图像用Efilm软件系统处理，利用Ansys-5．7大型计算机软件建立股骨上段三维有限元异物同构模型，模拟股骨头内囊性变。施加3种不同载荷，分析股骨头内应力分布情况。结果：股骨头受压后，中央区域表现为压应力，而前方和后方区域则表现为张力，符合球体受压后的膨胀趋势。股骨头负重区下方及其内侧和外侧的囊性变应力集中最明显，易引起股骨头塌陷。当囊性变位于股骨头的前方、后方、中心和下方时，其上下缘的应力集中不是很明显，股骨头塌陷断裂风险不大。结论：股骨头内不同部位的囊性变对股骨头缺血性坏死的生物力学影响是不同的，三维有限元应力分析法可以预测坏死股骨头的塌陷，并指导临床选用适当的显微外科治疗方法。     

PI3K/AKT信号通路调控股骨头坏死的相关机制

文题释义： 股骨头坏死：又称股骨头缺血性坏死,由多种因素造成股骨头血供障碍,从而引起软骨下区的软骨细胞和骨细胞得不到所需的营养物质而坏死并伴随局部骨质疏松,最终因外力导致股骨头塌陷。该病常易引起股骨头功能活动障碍,致残率较高,已成为骨科临床常见复杂性疾病之一。 PI3K/AKT信号通路：磷脂酰肌醇(PI3K)是一种位于胞质的脂质激酶,而AKT是PI3K通路中的一种关键激酶(丝氨酸/苏氨酸激酶),亦名蛋白激酶。AKT激活需要丝氨酸473(AktSer473)和苏氨酸308(Akt-Thr 308)的膜相互作用和磷酸化,经多种因素刺激后,PH结构域与PI3K产生的磷脂酰肌醇3,4,5-三磷酸(PIP3)相互作用,使胞浆AKT进入质膜;接着Akt-PIP3相互作用,通过域间构象变化将AKT诱导为开放的构象异构体,暴露Thr308和Ser473以用于磷酸肌醇依赖性蛋白激酶的后续磷酸化,而Thr308和Ser473的磷酸化完全激活AKT,从而通过磷酸化各种下游激酶,参与多种调节细胞的增殖和发育,在多个领域如癌症、血管再生、骨质疏松发挥了重要的调节作用从而通过磷酸化各种下游激酶,参与多种调节细胞的增殖和发育,在多个领域如癌症、血管再生、骨质疏松发挥了重要的调节作用。 背景：近年来随着医学研究不断深入,发现PI3K/AKT信号通路对血管修复再生、成骨细胞分化增殖、破骨细胞骨分化有调控作用,这对治疗股骨头坏死来说至关重要。 目的：就近年来PI3K/AKT信号通路调控股骨头坏死相关机制的主要研究进展做一简要概述,旨在为今后股骨头坏死的治疗提供新思路。 方法：检索PubMed、MEDLINE数据库、万方、CNKI、维普及中国生物医学文献数据库2012至2019年相关国内外文献,包括：①股骨头坏死的流行病学及相关病因病机研究文献;②PI3K/AKT通路相关机制研究文献;③PI3K/AKT对血管修复再生相关因素的影响研究文献;④PI3K/AKT对成骨细胞分化增殖相关因素调控的研究文献;⑤PI3K/AKT对破骨细胞分化等功能相关因素的调控研究文献。共纳入62篇文献分析总结。 结果与结论：①PI3K/AKT信号通路经多项动物实验已证实可对血管修复再生、成骨细胞分化增殖凋亡与破骨细胞分化相关因素进行有效调控,在认识这些通路机制基础上研发相关药物提高股骨头坏死早期保守治疗成功率具有远大发展前景及潜力,为未来治疗股骨头坏死开辟了新道路,也给患者及其家属带来新希望;②而根据患者不同股骨头坏死情况如何运用PI3K/AKT信号通路指导治疗成为该项技术的突破点及挑战,需要后期更多研究去探索。 ORCID: 0000-0002-3771-335X(宋世雷) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

酒精性和激素性股骨头坏死的发病与脂质代谢

背景：非创伤性股骨头坏死的发病机制存在各种理论学说,脂质代谢异常是其中一种假说,但是脂质代谢如何参与骨坏死的发病机制仍不清。 目的：通过对激素性和酒精性骨股头坏死患者血脂改变及股骨头置换标本形态计量学观察分析,探讨脂质代谢改变在非创伤性骨坏死中的作用。 方法：选择股骨头坏死住院患者162例,包括酒精性骨股头坏死57例,激素性骨股头坏死63例,创伤性骨股头坏死42例,其国际骨循环分期为(ARCO)Ⅱ~Ⅳ期。患者入院后常规抽空腹静脉血行三酰甘油、低密度脂蛋白等血脂检测。各组选取12例关节置换股骨头标本,股骨头冠状面正中剖开,在负重区和非负重区取材,对骨髓造血面积、脂肪细胞密度、脂肪细胞直径和脂肪细胞面积等行形态计量学观察。 结果与结论：酒精性股骨头坏死患者血三酰甘油升高率显著高于激素性和创伤性股骨头坏死患者(P < 0.05)。酒精性股骨头坏死患者血低密度脂蛋白降低率明显高于激素性和创伤性股骨头坏死(P < 0.05)。与激素性骨坏死患者相比,酒精性股骨头坏死患者脂肪细胞面积和脂肪细胞直径大,但造血面积减小,且差异有显著性意义。推测脂质代谢改变在酒精性股骨头坏死晚期起重要调节作用,而在激素性股骨头坏死晚期作用不明显。     

Relationships Between Femoral Strength Evaluated by Nonlinear Finite Element Analysis and BMD, Material Distribution and Geometric Morphology

Precise quantification of femur strength and accurate assessment of hip fracture risk would help physicians to identify individuals with high risk and encourage them to take preventive interventions. A major contributing factor of hip fracture is the reduction of hip strength, determined by the bone quality. Bone mineral density (BMD) alone cannot determine bone strength accurately. In this paper, subject-specific quantitative computer tomography (QCT) image-based finite element analyses were conducted to identify the quantitative relationships between femoral strength and BMD, material distribution and geometric morphology. Sixty-six subjects with QCT data of hip region were selected from the MrOS cohorts in Hong Kong. Subject-specific nonlinear finite element models were developed to predict strengths of proximal femurs. The models took non-linear elasto-plasticity and heterogeneity of bone tissues into consideration and derived bone strengths with proper bone failure criteria. From finite element analysis (FEA), relationships between femoral strength and BMD, material distribution, and geometric parameters were determined. Results showed that FEA-predicted femoral strength was highly correlated with BMD, material distribution, height, weight, diameters of femoral head (HD), and femoral neck (ND), as well as the moment arm for femoral neck bending-offset (OFF). Through principal components analysis, three independent principal components (PCs) were extracted. PC1 was the component of bone material quality. PC2 included height, weight, HD, and ND. PC3 mainly represented OFF. Multivariate linear regression showed that the PCs were strongly predictive of the FEA-predicted strength. This study provided quantitative information regarding the contributing factors of proximal femur strength and showed that such a biomechanical approach may have clinical potential in noninvasive assessment of hip fracture risk.     

人工股骨头置换治疗严重股骨转子间骨折的有限元分析

目的　建立股骨转子间骨折、人工关节假体的三维数字模型,应用有限元对人工股骨头置换术后的股骨应力分布进行分析,评价置换术后的初始稳定性。 方法　利用螺旋CT对志愿者的左侧股骨进行断层扫描获取图像数据,经Mimics软件和Unigraphics建模软件处理,重建股骨三维模型。在此基础上,建立股骨转子间骨折、标准柄股骨假体三维实体模型,最后利用有限元分析软件Ansys10.0建立人工股骨头置换术治疗股骨转子间骨折的三维有限元模型,并对该模型进行生物力学分析。 结果　应力分析显示：正常股骨的应力由近端向远端逐渐上升,并于中下段达到最高。同时人工股骨头假体的应力集中于中段,与正常股骨的应力变化基本一致。人工股骨头置换没有改变股骨总体的应力模式,股骨距部位未见明显的应力集中区,依然是由近端向远端逐渐增加,应力峰值区域亦于全长股骨的中下段。 结论　标准柄人工股骨头置换治疗股骨转子间骨折不会引起股骨应力分布的明显改变,可以获得重建后的初期稳定。     

Finite Element Analysis of the Multiple Drilling Technique for Early Osteonecrosis of the Femoral Head

We used finite element (FE) method to investigate the effect of the drilling number and entry location of holes used in the multiple drilling technique on the stress and strain state in femur. Different three-dimensional FE models of a human hip joint with or without multiple drilling were fabricated using computed tomographic images obtained from the hip joint of a cadaver. The analysis technique was evaluated in a compression test using the cadaver specimen and FE analysis for the test using an FE model of the specimen. Von Mises stresses, principal stresses, and principal strains in the cancellous and cortical bone were calculated by using the different models, and changes in these values in relation to drilling number and entry hole locations were evaluated. Calculated peak values were much smaller than the yield strength, tensile strength, and yield strain of the cancellous and cortical bone for all cases of multiple drilling. Our results support that the multiple drilling technique for osteonecrosis of the femoral head is a stable operation technique.     

骨髓间充质干细胞治疗股骨头坏死的评价

背景：股骨头坏死的治疗方法很多,但目前还没有满意的方法能促进坏死股骨头的修复。近年来,骨髓间充质干细胞移植治疗早期股骨头坏死缺的了一定的效果。 目的：综述骨髓间充质干细胞在股骨头坏死治疗中的应用进展及存在的问题。 方法：应用计算机检索PubMed数据库、万方数据库及CNKI中国知网数据库1999至2012年相关文献,选择骨髓间充质干细胞的分离、培养、分化、细胞标记及体内示踪研究,骨髓间充质干细胞移植治疗股骨头坏死的基础及临床研究,共纳入39篇文献进行综述。 结果与结论：目前骨髓间充质干细胞的分离方法有贴壁筛选法、密度梯度离心法、流式细胞仪分离法和免疫磁珠分选法;常用的细胞标记及示踪法有同位素示踪法、抗原标记法、抗原标记法、荧光染料标记法和MRI对比增强剂标记法。骨髓间充质干细胞治疗股骨头坏死的方法有髓芯钻孔减压联合骨髓间充质干细胞注射移植治疗股骨头坏死、介入加骨髓间充质干细胞治疗股骨头坏死、基因转染骨髓间充质干细胞移植治疗股骨头坏死、骨髓间充质干细胞的组织工程技术治疗股骨头坏死。虽然近年来对骨髓间充质干细胞移植治疗股骨头缺血坏死的研究取得了很大进展,但仍存在不少问题需要进一步研究。