基于运动学分析的膝关节动态旋转对位与屈伸轴线的研究

发布时间：2018-06-09 14:45

本文选题：膝关节 + 运动学　；参考：《第三军医大学》2015年博士论文

【摘要】：研究背景膝关节的运动学是理解膝关节的生理功能以及病理改变的基础科学。与生物力学一样,它也是诸多临床手术的基础,如全膝关节置换术(total knee arthroplasty,TKA)、前交叉韧带重建术等。在过去的一百多年中,有诸多的解剖学、生物力学的学者及临床医生对膝关节的运动学进行了广泛的研究。由于运动本身的复杂性,既往学者建立了多种理论和模型来对膝关节的运动进行解释和描述。在这些工作的基础上,现代的膝关节手术技术有了飞速发展。其中最典型的是TKA。早期的TKA手术具有较高的失败率和较短的假体寿命,而现代的TKA尽管仍存在一些亟待解决的问题,但成功率已经大幅提高,成为被学界广范认可的治疗终末期骨性关节炎的金标准。尽管如此,在膝关节运动学的有关研究中,仍有一些问题尚未被完全阐明。其中,两个重要的问题是膝关节的生理对位和屈伸轴线(flexion-extension axis,FEA)的测定。对于前者,既往的研究者对冠状面和矢状面的对位问题已较为明确。比如在冠状面,学者们通常认为在理想状态下从股骨头中心到踝关节中心走行的下肢力线应经过膝关节的中心。然而对于膝关节在横断面的对位,既往的研究则较为匮乏,并且缺少一致性的结论。这种情况很大程度上是由于膝关节的横断面对位容易受到膝关节运动的影响;由于胫骨与股骨的相对旋转是伴随着关节屈伸而存在的固有运动,膝关节横断面的对位也是随着屈膝角度实时变化的。从生物力学角度来说,这种在功能活动中表现出的动态对位关系对于膝关节的生理功能(如髌股关节功能等)以及临床诊疗(如TKA中胫骨假体的旋转对位等)应具有更重要的意义。在既往有限的针对膝关节横断面对位关系的研究中,绝大多数考察的是伸直位时静态的对位关系,而对基于运动学的动态对位则鲜有涉及。对于膝关节的FEA,在过去的几十年中学者们已从很多不同的角度对其进行了研究。早期的学者认为膝关节的FEA不是固定的,而是随着屈膝角度的变化在股骨远端按照一定的规律浮动。比如针对二维运动的“瞬时旋转中心”和针对三维运动的“瞬时旋转轴”的概念。这种非固定的旋转轴心的数学表达非常复杂,不利于临床医生掌握和应用。近年来的研究者倾向于认为膝关节是围绕着两条固定的轴线运动:围绕着fea进行屈伸,同时围绕着另一条竖直轴线(longitudinalaxis,lra)进行内外旋。该模型简化了运动的表述形式,同时可以将固定化的功能轴线和解剖轴线进行关联。fea的位置和方向对临床具有重要参考价值,比如tka中假体的设计和安装等。因此对其进行准确的解剖定位十分重要。然而,目前学界对于fea的解剖位置仍然存在争议。既往的学者认为股骨的髁上轴(transepicondylaraxis,tea)与fea具有一致性。然而这一结论被最近的实验所质疑。学者们发现tea的方向在屈膝中会发生改变,因此不符合固定旋转轴的要求;另一些学者主张连接股骨后髁中心的几何中心轴(cylinderaxis,ca)才是与fea最接近的解剖轴线,但对于该结论目前仍需更多的实验来验证。此外既往对于fea的计算方法也存在一定缺点。它要求先通过反复的膝关节内外旋实验来定位lra,再根据lra的位置测量fea。这种方法仅适合膝关节标本的体外测量实验,而难于在活体运动学采集中应用。因此开发一种新的计算fea的方法也十分必要。本研究的目标是,首先建立一套基于双平面x线摄影结合3d模型与2d影像配准技术的膝关节运动学检测方法,并对其准确性进行验证。在此基础上,采集正常膝关节在体负重情况下的运动学数据,分析股骨与胫骨在横断面上动态的对位关系。对此我们定义了一个股骨在运动过程中综合性的前-后方向,并将其和多条胫骨的解剖参考轴线进行对比。第三个目标是建立一种新的方法对fea进行计算,随后将fea同tea和ca两条解剖轴线的位置进行对比,判断哪一条可以更好地作为fea的解剖替代。这些功能与解剖的关系的建立将为膝关节的基础研究和临床提供有意义的参考。研究方法1、双平面x线摄影与三维模型-二维影像配准技术的建立及验证研究。我们通过一台固定式数字x光机(digitalradiography,dr)与一台移动式dr组建双平面x线影像采集系统。两台dr在场地中互相垂直安放,x线束相交的区域为有效成像区域。受检者可以在成像区域中完成膝关节的负重屈伸运动。在每一个屈膝的位置,两台dr可以同时从两个角度捕捉目标膝关节的x线影像。随后通过ct扫描及三维重建获取目标膝关节的几何实体模型。三维模型与二维模型的配准在现有的计算机三维建模软件中完成。配准的虚拟环境严格按照运动学采集时实验室的物理环境的比例设置。配准的过程依靠手动完成,采用平移和旋转的方式对几何模型的空间位置进行调整,以模型轮廓和双平面影像轮廓达到完美匹配为目标。在对多个屈膝位置的影像进行配准之后,通过对模型的整合即可获取膝关节连续运动的轨迹。对于该方法的验证,我们采用尸体标本进行。首先将膝关节标本固定在某个屈膝角度,并进行ct扫描和三维重建,获取的模型作为标准参照。随后采用双平面x线摄影与三维模型-二维影像配准的方法对同一标本进行检测,将配准的模型与上述标准参照进行对比,从而对系统误差进行评估。2、膝关节横断面的动态旋转对位研究利用如前述所建立的运动学采集方法,我们采集了20例健康成人志愿者单侧膝关节的运动学数据。对于每个受试者,分别采集其在单腿弓步屈膝运动下0°、15°、30°、60°、90°和120°时的运动学数据。在0°的模型中,确定一条股骨的前后轴线(femoralanteroposterioraxis,faa),并追踪该轴线的方向在上述屈膝位置中的变化。在此基础之上,计算出一个综合性的方向,即动态股骨前后轴线(femoralanteroposterioraxisofmotion,faam),该方向将与各屈膝角度下的faa保持最小的误差平方和。我们认为faam是一条代表了在整个动态屈膝过程中股骨综合性的前-后方向的轴线。在此基础上,faam与数条定义在胫骨上的解剖参考轴线的位置进行比对,从而建立解剖-功能的关系。对于这些轴线,测量它们与faam间角度偏差。此外,还着重考察了faam与胫骨结节间的位置关系。3、膝关节的屈伸轴线的研究基于上一部分研究中建立的20例样本的膝关节运动学数据库,我们开发了一个新算法对fea进行计算。简而言之,我们首先将股骨的三维模型转化为表面点云数据集;获取并追踪点云中每个点的初始坐标值以及其在整个屈膝过程中的变化,并计算坐标值在竖直方向的变化累积值。随后在点云集中,筛选出两个累积变化值最小的点,分别位于股骨内髁和股骨外髁表面。进而我们将连接上述两点的直线定义为fea。该算法的基本思想是,圆形刚体在平面上滚动时,其旋转中心应始终与平面间保持相对恒定的距离,而旋转中心以外的点则会出现较大幅度的上下起伏。在此基础之上,我们比较了fea与股骨远端两条常用轴线间的位置关系;这两条轴线包括tea和ca。测量包括fea、tea与ca三者之间的在平面以及三维空间的角度差异,以及三条轴线位于股骨髁表面的端点间的距离。基于此,tea与fea以及ca与fea间的匹配程度得以进行直接的比较。结果1、本研究所建立的双平面x线摄影与三维模型-二维影像配准技术可以有效地对膝关节负重状态下的运动学进行检测,并保持较高精度。根据尸体验证实验的结果,该方法在前后、内外以及远近方向上平移自由度的平均偏差分别为0.80mm,0.81mm和0.70mm;在冠状面、矢状面以及横断面三个平面上旋转自由度的平均偏差分别为0.79°,0.88°和1.06°。2、使用上述建立的方法成功获取了所有参检志愿者的运动学信息。faa在从伸直位到屈膝的过程中表现出外旋的趋势,在屈膝90°时达到最大(11.6°)。在参与测量的解剖轴线当中,没有任何一条可以与faam完全匹配。它们与faam的角度差异从外旋11.0°到内旋9.7°。然而,当faam经过胫骨平台中心时,其倾向于与胫骨结节相交于其内侧1/3部分,即内侧缘与中内1/3点之间。3、在所有样本中均成功计算出了fea。其从股骨后髁的中心区域穿过。在参与对比的两条解剖轴线中(tea与ca),fea与tea在三维空间以及横断面的角度差异高于fea与ca(三维:3.45°vs1.98°,p0.001;横断面:2.72°vs1.19°,p=0.002),但两者在冠状面则没有显著差异(1.61°vs0.83°,p=0.076)。关于三条轴线在股骨髁表面的端点,fea与tea在内侧面的端点间的距离显著高于fea与ca(6.7mmvs1.9mm,p0.001);而在外侧面两者没有显著差异(3.2mmvs2.0m,p=0.16)。结论1、本研究所建立的双平面x线摄影与三维模型-二维影像配准技术,是一个检测膝关节在体负重状态下运动学的有效方法。其具有较高的精度,在平移和旋转自由度上的偏差可以分别控制在1mm以下和1°左右。与其他的运动学检测手段,比如光学运动采集、mri以及x线立体摄影测量等相比,我们所建立的方法在易用性、准确性和可行性间达到了一个较好的平衡,可以满足后续实验的需要。2、目前在膝关节中较为常用的几条解剖参考轴线并不能准确地指示膝关节在横断面上的动态对位。与之相比,后者与胫骨结节的中内三分之一部分可能存在更多的相关性。本研究所发现的这种功能与解剖的关系可帮助我们更好地理解膝关节的生理功能。此外该发现也可能为tka提供一定的理论支持。针对目前临床所使用的利用胫骨结节中内1/3作为胫骨假体旋转对位的解剖参考标志的方法,本研究为其提供了一定的实验依据。3、我们建立的新方法可以基于连续的膝关节运动学数据对fea进行计算。膝关节的fea并不与tea相吻合,与之相比,它与ca在空间上更加接近。因此ca可能是fea的一个更好的解剖替代。本研究所发现的这种功能与解剖的关系可帮助我们更好地理解膝关节的生理功能。由于CA更接近于FEA,它可能具有更大的临床应用价值。
[Abstract]:The kinematics of the knee joint is the basic science to understand the physiological functions and pathological changes of the knee joint. Like biomechanics, it is also the basis of many clinical operations, such as total knee replacement (total knee arthroplasty, TKA), anterior cruciate ligament reconstruction, and so on. In the past more than 100 years, there are many anatomy and organisms. Mechanical scholars and clinicians have conducted extensive research on the kinematics of the knee joint. Due to the complexity of the motion itself, a variety of theories and models have been established to explain and describe the motion of the knee joint. On the basis of these work, modern knee surgery techniques have developed rapidly. The most typical of these is TKA. Early TKA surgery has a high failure rate and a shorter prosthesis life, while the modern TKA still has some problems to be solved, but the success rate has been greatly improved, which has become the golden standard for the treatment of end-stage osteoarthritis of the end of the study. The two important questions are the physiological alignment of the knee and the flexion-extension axis (FEA). For the former, the former researchers have been more explicit about the coronal and sagittal facet. For example, on the coronal plane, the learners generally believe that the femoral head is from the center of the femoral head to the center of the femoral head. In the center of the ankle joint, the force line of the lower extremities should go through the center of the knee joint. However, the previous study is relatively scarce and lacks consistency in the cross section of the knee joint. This is largely due to the vulnerability of the knee joint to the knee joint movement; the relative of the tibia and the femur. Rotation is an inherent movement associated with joint flexion and extension, and the cross section of the knee is also changed with the angle of knee flexion. From the biomechanical point of view, the dynamic alignment of the functional activities in the functional activities (such as patellar joint function, etc.) and clinical diagnosis (such as tibial sham in TKA) In the previous limited study of the position relationship of the knee joint transection, the overwhelming majority of the investigation is the static alignment at the straight position, while the dynamic alignment based on the kinematics is rarely involved. For the FEA of the knee joint, many scholars have gone from the past few decades. The early scholars believe that the FEA of the knee joint is not fixed, but is fluctuated at the distal femur with a variation of the angle of the knee. For example, the concept of "instantaneous rotation center" for two-dimensional motion and the concept of "instantaneous axis of rotation" for three-dimensional motion. This non fixed rotating axis. The mathematical expression is very complex and is not conducive to the mastery and application of the clinicians. In recent years, researchers tend to think that the knee joint is around two fixed axes motion: the flexion and extension around the FEA and the internal and external rotation around another vertical axis (longitudinalaxis, LRA). The location and direction of the.Fea associated with the immobilized functional axis and the anatomical axis are of important reference value to the clinic, such as the design and installation of the prosthesis in the TKA. Therefore, it is important to make an accurate anatomical location for it. However, there is still a dispute over the anatomical position of FEA. The transepicondylaraxis (tea) is consistent with FEA. However, this conclusion has been questioned by recent experiments. Scholars have found that the direction of tea will change in the knee and therefore does not meet the requirements of the fixed axis of rotation; other scholars argue that the geometric center axis (cylinderaxis, CA) connecting the posterior condyle center of the femur (cylinderaxis, CA) is the closest to FEA The anatomic axis, however, still needs more experiments to verify this conclusion. In addition, there are some shortcomings in the previous calculation method for FEA. It is required to locate LRA through repeated internal and external rotation experiments of the knee joint, and then measure fea. according to the position of LRA only suitable for the test of the knee joint specimens in vitro, but difficult to live in. It is also necessary to develop a new method of calculating FEA. The aim of this study is to establish a set of knee joint kinematics detection methods based on double plane X-ray photography combined with 3D model and 2D image registration technique, and to verify its accuracy. On this basis, the normal knee joint is collected in body negative. The kinematic data under heavy circumstances analysis the dynamic alignment of the femur and tibia on the cross section. We define a comprehensive front and back direction of a femur during the movement and compare it with the anatomical reference axis of the multiple tibia. The third goal is to establish a new method to calculate the FEA, and then the FEA Comparison with the position of the two anatomical axes of tea and Ca to determine which one can be a better substitute for the anatomy of FEA. The establishment of the relationship between these functions and anatomy will provide a meaningful reference for the basic research and clinic of the knee joint. Method 1, biplane X-ray photography and three-dimensional model - two-dimensional image registration technology We set up a dual plane X-ray image acquisition system with a fixed digital X-ray machine (digitalradiography, Dr) and a mobile Dr. Two sets of Dr are placed vertically in the site. The area of the X-ray beam intersection is an effective imaging area. The receiver can perform the flexion and extension movement of the knee joint in the imaging area. The position of the knee, two DR can capture the X-ray images of the target knee joint from two angles. Then, the geometric entity model of the target knee joint is obtained by CT scanning and three-dimensional reconstruction. The registration of the three-dimensional model and the two-dimensional model is completed in the existing computer 3D modeling software. The virtual environment of registration is strictly according to the kinematic acquisition. The proportion of the physical environment in the laboratory is set. The registration process relies on manual completion. The spatial position of the geometric model is adjusted by translation and rotation. The model contour and the biplane image contour are matched perfectly as the target. After the registration of the images of multiple knees, the integration of the model can be obtained. To verify the continuous motion of the knee joint, we use the cadaver specimens to verify the method. First, the specimens of the knee joint are fixed on a knee flexion angle, and the CT scan and three-dimensional reconstruction are used as the standard reference. Then the same specimen is used by the double plane X-ray photography and the three-dimensional model - two-dimensional image registration method. By comparing the registration model with the above standard reference, the system error is evaluated by.2. The dynamic rotation of the knee joint cross section is used to collect the kinematic data of the Dan Cexi joints of 20 healthy adult volunteers. The kinematic data are collected at 0, 15, 30, 60, 90 and 120 degrees under the single leg knee flexion. In the 0 degree model, the axis of the femur (femoralanteroposterioraxis, FAA) is determined and the direction of the axis changes in the position of the knee flexion. On this basis, a comprehensive direction is calculated. The axis of the femur (femoralanteroposterioraxisofmotion, faam), which will keep the minimum square sum of the error of the FAA under each knee angle. We think that faam is an axis that represents the integrated front and rear direction of the femur during the entire dynamic knee flexion. On this basis, faam and several sections define the anatomical parameters on the tibia. The position of the axis is compared, and the relationship between the anatomy and function is established. For these axes, the angle deviations between them and faam are measured. In addition, the relationship between the faam and the tibial tubercle is also focused on the relationship between the position of the tibial tubercle.3, the flexion and extension axis of the knee joint, which is based on the kinematics database of the knee joint of 20 cases established in the last part of the study. We have developed a new algorithm to calculate the FEA. In short, we first transform the three-dimensional model of the femur into a surface point cloud data set; get and track the initial coordinates of each point in the point cloud and the changes in the whole knee flexion, and calculate the cumulative value of the coordinate values in the vertical direction. Then, in the point cloud, the sieves are concentrated. Two points with the smallest cumulative change values are selected at the inner condyle of the femur and the surface of the outer condyle of the femur respectively. Then we define the straight line connecting the two points as fea.. The basic idea of the algorithm is that when the circular rigid body rolls on the plane, the rotation center should always keep the constant distance from the plane, and the point outside the rotation center. On the basis of this, we compare the position relationship between FEA and the two common axis of the distal femur; the two axes include the tea and ca. measurements of the differences in the plane and the three-dimensional space between the FEA, the tea and the CA three, and the distance between the three axes at the surface of the femur condyle. Based on this, the matching degree between tea and FEA and Ca and FEA can be directly compared. Results 1, the biplane X-ray photography and three-dimensional image registration technique established by this study can detect the kinematics of the knee joint effectively and maintain high accuracy. The method is based on the results of the corpse verification experiment. The average deviations of the translational degrees of freedom were 0.80mm, 0.81mm and 0.70mm, respectively, and the average deviations of the rotational degrees of freedom on the coronal, sagittal and cross sections of the three planes were 0.79, 0.88 and 1.06.2 respectively. The kinematic information.Fa of all the volunteers was successfully obtained by the above method. A shows a trend of external rotation during the extension of the position to the knee, reaching the maximum (11.6 degrees) at 90 degrees. No one in the anatomic axis participating in the measurement can be fully matched with the faam. The difference from the angle of the faam from the outer rotation 11 degrees to the internal rotation 9.7 degrees. However, when faam passes through the tibial plateau center, it tends to be with the tibia. The bone nodules intersected in the medial 1/3 part, that is,.3 between the medial margin and the middle 1/3 point. In all the samples, fea. has been successfully calculated from the central region of the posterior femoral condyle. In the two dissection axes (tea and CA), the differences between FEA and tea in the three-dimensional space and the transverse section are higher than FEA and Ca (3.45 degrees vs1.98, P0). .001; cross section: 2.72 degree vs1.19, p=0.002), but there is no significant difference between the two on the coronal plane (1.61 degrees vs0.83, p=0.076). The distance between the three axes on the surface of the femoral condyle and the distance between FEA and tea at the medial surface is significantly higher than that of FEA and Ca (6.7mmvs1.9mm, p0.001), but there is no significant difference between the outer sides (3.2mmvs2.0m,). 1, the biplane X-ray photography and three-dimensional image registration technique established by this study are an effective method to detect the kinematics of the knee joint under the body load condition. It has high accuracy. The deviation of the translational and rotational degrees of freedom can be controlled under 1mm and 1 degrees respectively. For example, optical motion acquisition, MRI and X-ray stereopotrometry, we have achieved a better balance between the usability, accuracy and feasibility of the method, which can meet the needs of.2 in the follow-up experiment. At present, several commonly used axes in the knee joint can not accurately indicate the knee joint in the cross section. In contrast, the latter may have more relevance to the 1/3 parts of the tibial tubercle. The relationship between this function and the anatomy can help us to better understand the physiological functions of the knee joint. Moreover, the discovery may also provide some theoretical support for TKA. This study has provided some evidence for the use of 1/3 in the tibial tubercle as an anatomical reference mark for the rotation of the tibial component.
【学位授予单位】：第三军医大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R687.3

【相似文献】