【作者】 王建平；

【导师】 王成焘；

【作者基本信息】 上海交通大学 ， 机械设计及理论， 2010， 博士

【摘要】 本文以“植入假体的生物摩擦学关键基础问题研究”以及“中国力学虚拟人”国家自然科学基金重点项目为支撑,在建立人体膝关节“骨组织-软组织”三维几何模型以及进行屈曲运动分析的基础上,分别建立了自然膝关节以及全膝关节置换后的膝关节的几何解剖模型,进行膝关节骨骼建模精度验证与分析,模型包括股胫关节、髌股关节的骨组织及软骨、半月板、韧带等软组织。提出基于三维图像配准的膝关节运动分析方法,进行膝关节屈曲运动分析。分别建立了自然膝关节以及全膝关节置换后的膝关节的几何解剖模型和动态有限元模型,构建膝关节屈曲运动生物力学实验系统,模拟人体下蹲动作进行了相应尸体实验。针对自然膝关节和全膝置换后膝关节屈曲运动的运动和接触的动态特征进行分析,并与相应的尸体实验的结果进行验证分析。结果表明,该有限元模型能够对于膝关节屈曲运动的运动和应力等生物力学特征进行合理的预测。所建立的膝关节运动分析方法以及膝关节生物力学实验系统,能够有效的测量和分析人体自然和全膝置换后膝关节屈曲运动的运动和接触特征。具体的研究内容包括:(1)人体膝关节“骨组织-软组织”几何建模。通过研究人体解剖结构对于人体生物力学行为的影响,保留绝大多数对于人体生物力学行为起到主要作用的组织,从而建立一个包含人体膝关节主要组织在内的对于膝关节生物力学行为起到决定性影响的人体膝关节几何解剖模型。构建的膝关节模型包括:股骨、胫骨、髌骨、软骨、半月板、前后交叉韧带、内外侧副韧带、股四头肌腱和髌腱。同时,模拟临床手术的要求,分别对膝关节股骨、胫骨和髌骨进行截骨;针对重建的膝关节模型,采用目前临床普遍应用的PFC固定平台人工膝关节,与前者在CAD环境下模拟装配,从而构成分析人工膝关节置换的TKR模型。模型可以用来做植入假体的几何仿真和有限元力学分析,为人体膝关节的分析提供了一个目前该研究领域中较为完整和解剖相似性较高的模型。通过测量三个正交方向上规则骨的六个面之间的线性和角度误差来表达测量点之间距离的建模误差,从而预测复杂曲面建模精度。避免了由于针对特征点进行测量所引起的由于特征点的选择所带来的较大的基础误差。为人体骨骼重建精度的评价提供参考。(2)通过运动捕捉系统进行人体典型屈曲运动-下蹲的运动测量,获得屈曲运动的基本特征。通过三维图像配准,将不同屈曲位的膝关节三维图像放在一致的坐标系下,建立膝关节各个骨组织的正交坐标系,通过运动坐标系坐标变换得到膝关节相对运动的数据。建立了一种基于三维几何解剖模型的结合三维图像配准和坐标变换进行膝关节相对运动分析的方法。(3)构建了一套测量自然和全膝置换膝关节屈曲运动的动态运动和接触应力测量系统,分别进行自然和全膝置换后膝关节屈曲运动的体外测试。该测试系统可以同步进行胫股关节和髌股关节测量,而且可以同步测量膝关节屈曲的运动和接触行为。通过该实验系统进行有限元模型的有效程度验证。(4)分别建立了天然膝关节以及全膝关节置换后的膝关节下蹲时的有限元模型,并进行了相应尸体实验,针对膝关节假体下蹲时的屈曲运动和接触应力的动态特征进行分析。模型包括股胫关节、髌股关节骨组织及其软骨、半月板、韧带和肌腱。并与相应的尸体实验的结果进行验证分析。该有限元模型能够对于膝关节下蹲时的运动和应力等生物力学特征进行合理的预测。不仅建立了自然膝关节的有限元分析模型,而且建立了全膝置换膝关节的有限元模型。该模型既可以同时模拟胫股关节和髌股关节的运动,又可以同步进行运动和接触等的生物力学分析。本文建立了包括人体主要骨与软组织的自然膝关节以及全膝关节置换后膝关节的几何解剖模型。进行膝关节下蹲运动测量以及膝关节相对屈曲运动分析。构建膝关节屈曲行为的运动和接触测量系统。建立了自然以及全膝置换后膝关节的动态有限元模型。分析自然及全膝置换后膝关节屈曲运动的生物力学特征,讨论人工膝关节设计的参考因素和方向。所建立的有限元模型和实验系统能够对于膝关节的运动、接触等力学行为进行评估,为临床膝关节全膝置换术和膝关节假体的设计提供有力的分析工具。研究结果可以为膝关节病理、康复研究以及人工膝关节设计提供参考。更多还原

【Abstract】 This research is supported by NSFC (Natural Science Foundation of China), Key Project‘Implanting prothesis’s biotribological key basic research’and‘Mechanical Virtual Human of China’. Based on reconstructed model of three-dimensional (3D) geometric knee including both bone and soft-tissue and the analysis of knee flexion motion, natural knee and post total knee arthroplastic knee three-dimensinal geometric models were built, the overall reconstruction precision of the 3D medical imaging of human knee bone was predicted. The models include femoral-tibial articulation, patella-femoral articulation and their bone, cartilage, meniscus and ligments. 3D registration combined with coordinate transformation technique was proposed and applied to investigate the relative flexion kinematics of the normal knee in vivo including stibio-femoral joint and patello-femoral joint. Dynamic finite element (FE) model of knee and post total knee replacement (TKR), which include tibio-femoral, patello-femoral articulations and the surrounding soft tissues, were developed in this research, to simulate both the kinematics and the internal stresses during knee flexion simulation. The biomechanical experimental system of knee flexion motion was set up to simulate human knee squatting using cadaver knees. The flexion motion and dynamic contact characteristics of knee joint and knee post TKR were analysed, and were verified by comparison with the data from cadaver in vitro experiment. Results showed that dynamic FE models of knee and knee post TKR are capable of predicting kinematics and contact stresses during flexion,and could be a efficient tool for the analysis of TKR and knee prosthesis design. Contents of this thesis are as following: (1) Three-dimensional bone and soft-tissue geometric knee and knee post TKR models. By the analysis of human knee anatomic structure impact on human biomechanical behavior, the main components of knee were included to be built as 3D geometric knee models.Quadriceps tendon, patella tendon, tibia collateral ligament, fibular collateral ligament, posterior cruciate ligament, anterior cruciate ligament, meniscus and femur, tibia, patella’s cartilage were built in knee model. Commonly adopted TKR components (Sigma PFC) were modeled in this research. The Simulation resection and prosthesis assembly were carried out on the natural knee models. By above mentioned, the 3D geometric model of knee joint post TKR was established. Both of above models are relatively comprehensive and higher comparability models for the analysis of knee, TKR and knee prosthesis design.The overall reconstruction precision of the 3D medical imaging of complex surfaces human bone was evaluated by acquiring not only translational but also angular errors in three orthogonal directions between six orthogonal planes on machined bone segments. In this way, the error based on the identification of anatomical landmarks was avoided. This method can provide a reference for assessing the sensitivity, reliability and accuracy of human bone reconstruction.(2) The typical flexion motion-squating was measured by motion capturing system. The basic motion characteristics of knee flexion were obtained. Different models of several flexion knee positions were aligned to the same coordinate system by using the technique of 3D registration algorithm. Moreover, as for each model of the knee, an improved orthogonal object coordinate system was built on femur, tibia and patella. By establishing orthogonal coordinates on each part of the knee, the Euler angle coordinate transformation was applied to acquire data of knee relative flexion kinematics. In this way, 3D registration combined with coordinate transformation technique was proposed and applied to study the relative kinematics of knee.(3) A dynamic biomechanical experimental in vitro system of knee and knee post TKR flexion motion was established. This system was used to simulate human knee squatting using cadaver knee. Not only the synchronal measurement of both tibio-femoral and patello-femoral articulations but also the synchronal measurement of both kinematics and contact can be implemented in this experiment system. By comparing the results of cadaver knee flexion to those of FE model analysis, the effective degree of FE model analysis could be evaluated.(4) Dynamic finite element model of knee and post TKR, which include tibio-femoral, patello-femoral articulations and the surrounding soft tissues, were developed in this research, to simulate both the kinematics and the internal stresses during squat simulation. The kinematic simulating results and the contact stresses distribution of a full deformable contact analysis of knee and prosthetic knee joint during squat were verified by comparing to data from in vitro experiment. The established dynamic FE models of knee and knee after TKR could be used to predict the biomechanical characteristics of kinematics and the contact stresses during flexion. Not only the knee FE model but also the FE model of knee post TKR was esteablished. By using these established models, analysis of both tibio-femoral and patello-femoral articulations can be synchronal. Also, the synchronal biomechanical analysis of both kinematics and contact can be obtained.The three-dimensional geometric model of knee and knee post TKR including key bone and soft-tissue were built in this research. The motion of knee squat was measured and the relative movement of knee flexion was investigaed. A dynamic biomechanical experimental in vitro system of knee and knee post TKR flexion motion was established. Dynamic finite element model of knee and post TKR were developed in this research. The biomechanical characteristics of knee and knee post TKR flexion were studied. And the reference factors and the prediction of artificial knee joint design were discussed in this research. The established dynamic FE models and experiment system are capable of predicting the kinematics and the stresses during knee flexion,and could be efficient tools for the analysis of TKR and knee prosthesis design. Results of this research could be references for the research of knee pathology, rehabilitation and prosthesis design.更多还原