基于三维有限元方法探索ACL断裂后胫股关节轨迹异常对半月板和软骨应力分布的影响
发布时间：2018-09-11 21:25
【摘要】：研究背景 前交叉韧带(anterior cruciate ligament，ACL)断裂可导致膝关节运动不稳，引起胫骨与股骨之间的位移和旋转异常。胫骨与股骨之间的运动关系比较复杂，包括6个自由度的位移和旋转，以及股骨内外侧髁的前后、内外和远近位移。ACL是维持膝关节正常活动的关键纽带。当ACL断裂后，膝关节在屈曲过程中会出现胫骨前移、内移和内旋增加。以往许多关于ACL断裂后膝关节运动的研究，把股骨的运动作为一个整体来看待，而忽略了内侧髁和外侧髁的运动。因此，ACL断裂对内外侧髁运动的影响在目前仍认识不足，表现在ACL断裂对内外侧髁前后位移的影响仍存在分歧，而且尚未有文献报道ACL断裂对内外侧髁内外和远近位移的影响。全面地了解ACL断裂后胫股关节6个自由度运动以及股骨内外侧髁运动的异常变化，将有助于进一步认识ACL断裂对股骨运动产生的影响，有助于改进ACL重建术的外科技术。 ACL断裂引起的胫股关节运动轨迹改变可进一步引发半月板和软骨继发性损伤。随着ACL断裂后胫股关节位移和旋转的改变，胫股软骨接触点在屈曲过程中出现后移和外移增加，从而引起关节负荷从负重区转移到非负重区，造成非负重区软骨应力增加。此外，ACL断裂后内侧半月板所承受的应力也明显增加。可见，ACL断裂会引起关节间应力重新分配，容易导致半月板和软骨继发性损伤。既往的研究很少对ACL断裂后半月板(前角、体部和后角)和软骨(胫骨软骨和股骨软骨)各部分的应力情况进行细分观察。临床观察显示，ACL断裂对半月板和软骨各部分的影响并不完全相同。因此，全面地了解ACL断裂后半月板和软骨各部分异常的应力分布，将有助于了解半月板和软骨上出现继发性损伤的好发部位以及了解潜在的损伤机制。 有限元分析法是获得膝关节半月板和软骨上应力分布的有效方法。该方法以研究对象的几何结构为基础构建生物力学模型，赋予恰当的材料属性后，加载负荷和边界条件，对研究对象进行受力分析和运动分析。有限元分析法可以克服体外实验中标本不易获得、标本不能重复使用等缺点，而且能获得体外实验不易获得的数据，如韧带张力，关节间的接触力、接触面积，半月板和软骨的应力、应变等。有限元分析法已成为研究关节生物力学的可靠手段。 在本文中，我们应用双平面X光技术全面地测量直立负重屈曲过程中，胫股关节6个自由度的运动以及股骨内外侧髁前后、内外和远近位移。直立负重比非负重能更好地反映和评估ACL断裂病理状态下的胫股关节运动。本文先建立应用该技术测量胫股关节运动的方法，以及验证该技术测量的准确性；接着，我们使用该技术全面地测量并分析膝关节在直立负重屈曲过程中，ACL断裂后胫股关节位移和旋转的变化；然后，我们把ACL断裂后胫股关节运动轨迹改变的数据应用到有限元模型中，模拟分析ACL断裂后内外侧半月板前角、体部和后角，以及内外侧胫骨软骨和股骨软骨上应力分布的变化。 研究方法 1.双平面X光技术测量胫股关节位移和旋转方法的建立与体外实验的验证。使用两台X光机从正交方向同时采集膝关节6个屈曲位置的双平面X光影像，CT扫描伸直位的膝关节并重建成胫股关节三维模型，然后用三维模型与双平面X光影像进行图像配准，获得6个屈曲位置的胫股关节模型，通过建立在模型上的关节坐标系测量出胫股关节在屈曲过程中的位移和旋转。验证过程如下：CT直接扫描处于6个屈曲位置的同一个膝关节，并重建成6个位置的胫股关节模型，通过同一个坐标系测量出胫股关节的位移和旋转，并以此运动数据作为参考标准，考查双平面X光技术所获得的胫股关节运动数据的准确性。 2.测量ACL断裂后直立负重屈曲过程中胫股关节的位移和旋转。应用双平面X光技术，测量单侧ACL断裂患者从伸直位到120°屈曲的弓步下蹲过程中，ACL断裂膝和正常对侧膝的胫股关节位移和旋转，然后对比分析患膝与健膝之间胫股关节位移和旋转的差异，获得ACL断裂后胫股关节运动轨迹改变的数据。 3.探讨ACL断裂对半月板和软骨应力分布的影响。应用有限元分析法计算出ACL断裂膝和正常膝中半月板和软骨各部分上的应力分布。构建胫股关节有限元模型，并对此模型的有效性进行验证。创建ACL断裂有限元模型，，把ACL断裂后胫股关节运动轨迹改变的数据作为边界条件应用到该模型中。计算出伸直位、15°和30°屈曲时ACL断裂模型和正常模型中半月板和软骨上的应力分布，并对比分析两个模型之间半月板和软骨各部分上应力的差异。 研究结果 1.双平面X光技术能较准确地测量胫股关节的位移和旋转。该技术的精确度在前后、内外和远近位移上分别为0.88mm、0.65mm和0.61mm，在屈伸、内外旋转和内外翻转上分别为1.03°、1.09°和0.76°。 2.膝关节在下蹲屈曲过程中，在伸直位和15°屈曲时，ACL断裂后股骨外侧髁的后移增加，伴随着股骨的后移和外旋增加。而对于内侧髁的前后位移，内外侧髁和股骨的内外、远近位移，以及股骨的内外翻转在ACL断裂后均与正常膝相似。 3.膝关节从15°到60°的下蹲屈曲阶段中，ACL断裂后外侧髁后移的幅度显著减少，这使得股骨后移和外旋的幅度也随之减少。而对于内侧髁前后移动的幅度，内外侧髁和股骨内外、远近移动的幅度，以及股骨内外翻转的幅度在ACL断裂后均与正常膝相似。 4.在伸直位到30°屈曲之间，ACL断裂后内外侧半月板上的应力均增加。在伸直位时，ACL断裂造成内侧半月板前角的应力增加明显，外侧半月板前角和体部的应力也有所增加；在15°和30°屈曲时，ACL断裂后内侧半月板后角的应力增加明显，而外侧半月板各部位的应力增加不明显。 5. ACL断裂后内外侧胫股软骨在伸直位到30°屈曲之间所承受的应力均增加，其中，内侧股骨软骨的应力增幅随着屈曲的增加而逐渐升高，内侧胫骨软骨的应力增幅随着屈曲逐渐下降，外侧间室中胫股软骨的应力增幅比较小。 研究结论 1.建立了双平面X光技术全面测量胫股关节位移和旋转的方法，经过验证，该技术有效可行。 2.在膝关节从伸直位到120°的下蹲屈曲过程中，ACL断裂主要改变了股骨外侧髁的前后运动，引起外侧髁在早期屈曲范围内向后松动，而且造成外侧髁在屈曲过程的中间阶段向后移动的幅度显著少于正常膝。 3.在膝关节从伸直位到30°屈曲之间，ACL断裂主要改变了胫股关节内侧间室的应力分布，引起内侧半月板前角和后角的应力分别在伸直位和屈曲位时明显大于正常膝，并造成内侧股骨软骨应力的增加幅度随着屈曲的加深不断升高。
[Abstract]:Research background
Anterior cruciate ligament (ACL) rupture can lead to instability of knee joint motion, resulting in displacement and rotation abnormalities between tibia and femur. When ACL ruptures, the tibia moves forward, moves inward, and turns inward. Many previous studies on the motion of the knee joint after ACL ruptures looked at the femoral movement as a whole, but ignored the movement of the medial and lateral condyles. The influence of ACL rupture on the anterior and posterior displacement of the medial and lateral condyles is still poorly understood, and the effect of ACL rupture on the anterior and posterior displacement of the medial and lateral condyles has not been reported in literature. To further understand the effect of ACL rupture on femoral movement is helpful to improve the surgical technique of ACL reconstruction.
With the change of displacement and rotation of tibiofemoral joint after ACL rupture, the tibiofemoral cartilage contact points appear to move back and out during the flexion process, resulting in the transfer of joint load from the load-bearing area to the non-load-bearing area, resulting in the non-load-bearing area. In addition, the stress on the medial meniscus increased significantly after ACL rupture. It is evident that ACL rupture can lead to stress redistribution between joints and secondary injury to the meniscus and cartilage. Previous studies have rarely studied the posterior meniscus (anterior horn, body and posterior horn) and cartilage (tibial cartilage and femoral cartilage) after ACL rupture. Clinical observation showed that the effects of ACL rupture on the meniscus and cartilage were not identical. Therefore, a comprehensive understanding of the abnormal stress distribution in the meniscus and cartilage after ACL rupture will be helpful to understand the predisposing sites of secondary injury on the meniscus and cartilage and the potential of secondary injury. Damage mechanism.
Finite element analysis is an effective method to obtain the stress distribution on the meniscus and cartilage of the knee joint.The biomechanical model is constructed on the basis of the geometric structure of the research object.After giving proper material attributes,loading loads and boundary conditions,the stress analysis and motion analysis of the research object are carried out.Finite element analysis can overcome the body. In the external experiment, the specimen is not easy to obtain and can not be reused, and the data which is not easy to obtain in the external experiment, such as ligament tension, joint contact force, contact area, meniscus and cartilage stress, strain and so on. The finite element analysis method has become a reliable means to study joint biomechanics.
In this paper, we used biplane X-ray technique to measure the tibiofemoral joint motion with six degrees of freedom during orthostatic weight-bearing flexion and the displacement of the femoral medial and lateral condyles. Then, we use this technique to measure and analyze the tibiofemoral joint displacement and rotation after ACL rupture during orthostatic load-bearing flexion. Then, we apply the data of tibiofemoral joint motion trajectory after ACL rupture to the measurement. In the finite element model, the changes of stress distribution in the anterior horn, body and posterior horn of the medial and lateral meniscus, tibial cartilage and femoral cartilage after ACL rupture were simulated and analyzed.
research method
1. Establishment of biplane X-ray technique for measuring tibiofemoral joint displacement and rotation and validation of in vitro experiments. Biplane X-ray images of six knee flexion positions were taken simultaneously from orthogonal directions by two X-ray machines. The knee joints in straight position were scanned by CT and reconstructed into three-dimensional models of tibiofemoral joint. After image registration, the tibiofemoral joint model with six flexion positions was obtained. The displacement and rotation of the tibiofemoral joint during flexion were measured by the joint coordinate system based on the model. The displacement and rotation of tibiofemoral joints were measured in each coordinate system, and the accuracy of tibiofemoral joint motion data obtained by biplane X-ray technique was examined.
2. Measure the displacement and rotation of tibiofemoral joints during orthostatic weight-bearing flexion after ACL rupture. Measure the displacement and rotation of tibiofemoral joints between ACL ruptured knees and normal contralateral knees during bowing and squatting from extension to 120 degree flexion with biplane X-ray technique. The difference of movement and rotation is obtained from the data of the movement of the tibiofemoral joint after ACL fracture.
3. Discuss the influence of ACL fracture on stress distribution of meniscus and cartilage. Calculate the stress distribution of meniscus and cartilage in ACL fracture knee and normal knee by finite element analysis. Construct the finite element model of tibiofemoral joint, and verify the validity of the model. The data of trajectory changes are applied to the model as boundary conditions. Stress distributions on the meniscus and cartilage are calculated in the ACL fracture model and the normal model at flexion of 15 and 30 degrees, and the differences of stresses on the meniscus and cartilage between the two models are compared and analyzed.
Research results
1. Biplane X-ray technique can measure the displacement and rotation of tibiofemoral joints more accurately. The accuracy of this technique is 0.88 mm, 0.65 mm and 0.61 mm respectively in internal and external displacement, 1.03 degrees in flexion and extension, 1.09 degrees in internal and external rotation and 0.76 degrees in internal and external inversion.
2. During squatting and flexion, the posterior displacement of the lateral condyle of the femur increases with the posterior displacement and lateral rotation of the femur after ACL rupture, while the anterior and posterior displacement of the medial condyle, the medial and lateral displacement of the medial condyle, the distal and near displacement of the medial and lateral condyle, and the inversion of the femur after ACL rupture are similar to those of the normal knee.
3. During knee flexion from 15 degrees to 60 degrees, the lateral condylar posterior displacement after ACL rupture was significantly reduced, which reduced the femoral posterior displacement and lateral rotation. Normal knees are similar.
4. The stress on the medial and lateral meniscus increases after ACL rupture between extension and 30 degree buckling. In extension, ACL rupture results in a significant increase in the stress in the anterior horn of the medial meniscus, and the stress in the anterior horn and body of the lateral meniscus also increases. The stress on the lateral meniscus is not obvious.
5. The stress of medial and lateral tibiofemoral cartilage increased with the increase of flexion, the stress of medial tibiofemoral cartilage decreased with the increase of flexion, and the stress of medial tibiofemoral cartilage decreased with the increase of flexion.
research conclusion
1. The method of measuring the displacement and rotation of tibiofemoral joint by biplane X-ray technique is established. It is proved that the technique is effective and feasible.
2. During knee flexion from extension to 120 degrees, ACL rupture mainly changes the anterior and posterior movement of the lateral condyle of the femur, causing the lateral condyle to loosen backwards in the early flexion range, and causing the lateral condyle to move backwards in the middle of the flexion process significantly less than the normal knee.
3. Between extension and flexion of the knee joint, ACL rupture mainly changes the stress distribution of the tibiofemoral medial compartment, causing the stress of the anterior and posterior horns of the medial meniscus to be significantly greater than that of the normal knee in the extension and flexion positions, and causing the stress of the medial femoral cartilage to increase with the deepening of flexion.
【学位授予单位】：第三军医大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：R686.5
本文编号：2237889
[Abstract]:Research background
Anterior cruciate ligament (ACL) rupture can lead to instability of knee joint motion, resulting in displacement and rotation abnormalities between tibia and femur. When ACL ruptures, the tibia moves forward, moves inward, and turns inward. Many previous studies on the motion of the knee joint after ACL ruptures looked at the femoral movement as a whole, but ignored the movement of the medial and lateral condyles. The influence of ACL rupture on the anterior and posterior displacement of the medial and lateral condyles is still poorly understood, and the effect of ACL rupture on the anterior and posterior displacement of the medial and lateral condyles has not been reported in literature. To further understand the effect of ACL rupture on femoral movement is helpful to improve the surgical technique of ACL reconstruction.
With the change of displacement and rotation of tibiofemoral joint after ACL rupture, the tibiofemoral cartilage contact points appear to move back and out during the flexion process, resulting in the transfer of joint load from the load-bearing area to the non-load-bearing area, resulting in the non-load-bearing area. In addition, the stress on the medial meniscus increased significantly after ACL rupture. It is evident that ACL rupture can lead to stress redistribution between joints and secondary injury to the meniscus and cartilage. Previous studies have rarely studied the posterior meniscus (anterior horn, body and posterior horn) and cartilage (tibial cartilage and femoral cartilage) after ACL rupture. Clinical observation showed that the effects of ACL rupture on the meniscus and cartilage were not identical. Therefore, a comprehensive understanding of the abnormal stress distribution in the meniscus and cartilage after ACL rupture will be helpful to understand the predisposing sites of secondary injury on the meniscus and cartilage and the potential of secondary injury. Damage mechanism.
Finite element analysis is an effective method to obtain the stress distribution on the meniscus and cartilage of the knee joint.The biomechanical model is constructed on the basis of the geometric structure of the research object.After giving proper material attributes,loading loads and boundary conditions,the stress analysis and motion analysis of the research object are carried out.Finite element analysis can overcome the body. In the external experiment, the specimen is not easy to obtain and can not be reused, and the data which is not easy to obtain in the external experiment, such as ligament tension, joint contact force, contact area, meniscus and cartilage stress, strain and so on. The finite element analysis method has become a reliable means to study joint biomechanics.
In this paper, we used biplane X-ray technique to measure the tibiofemoral joint motion with six degrees of freedom during orthostatic weight-bearing flexion and the displacement of the femoral medial and lateral condyles. Then, we use this technique to measure and analyze the tibiofemoral joint displacement and rotation after ACL rupture during orthostatic load-bearing flexion. Then, we apply the data of tibiofemoral joint motion trajectory after ACL rupture to the measurement. In the finite element model, the changes of stress distribution in the anterior horn, body and posterior horn of the medial and lateral meniscus, tibial cartilage and femoral cartilage after ACL rupture were simulated and analyzed.
research method
1. Establishment of biplane X-ray technique for measuring tibiofemoral joint displacement and rotation and validation of in vitro experiments. Biplane X-ray images of six knee flexion positions were taken simultaneously from orthogonal directions by two X-ray machines. The knee joints in straight position were scanned by CT and reconstructed into three-dimensional models of tibiofemoral joint. After image registration, the tibiofemoral joint model with six flexion positions was obtained. The displacement and rotation of the tibiofemoral joint during flexion were measured by the joint coordinate system based on the model. The displacement and rotation of tibiofemoral joints were measured in each coordinate system, and the accuracy of tibiofemoral joint motion data obtained by biplane X-ray technique was examined.
2. Measure the displacement and rotation of tibiofemoral joints during orthostatic weight-bearing flexion after ACL rupture. Measure the displacement and rotation of tibiofemoral joints between ACL ruptured knees and normal contralateral knees during bowing and squatting from extension to 120 degree flexion with biplane X-ray technique. The difference of movement and rotation is obtained from the data of the movement of the tibiofemoral joint after ACL fracture.
3. Discuss the influence of ACL fracture on stress distribution of meniscus and cartilage. Calculate the stress distribution of meniscus and cartilage in ACL fracture knee and normal knee by finite element analysis. Construct the finite element model of tibiofemoral joint, and verify the validity of the model. The data of trajectory changes are applied to the model as boundary conditions. Stress distributions on the meniscus and cartilage are calculated in the ACL fracture model and the normal model at flexion of 15 and 30 degrees, and the differences of stresses on the meniscus and cartilage between the two models are compared and analyzed.
Research results
1. Biplane X-ray technique can measure the displacement and rotation of tibiofemoral joints more accurately. The accuracy of this technique is 0.88 mm, 0.65 mm and 0.61 mm respectively in internal and external displacement, 1.03 degrees in flexion and extension, 1.09 degrees in internal and external rotation and 0.76 degrees in internal and external inversion.
2. During squatting and flexion, the posterior displacement of the lateral condyle of the femur increases with the posterior displacement and lateral rotation of the femur after ACL rupture, while the anterior and posterior displacement of the medial condyle, the medial and lateral displacement of the medial condyle, the distal and near displacement of the medial and lateral condyle, and the inversion of the femur after ACL rupture are similar to those of the normal knee.
3. During knee flexion from 15 degrees to 60 degrees, the lateral condylar posterior displacement after ACL rupture was significantly reduced, which reduced the femoral posterior displacement and lateral rotation. Normal knees are similar.
4. The stress on the medial and lateral meniscus increases after ACL rupture between extension and 30 degree buckling. In extension, ACL rupture results in a significant increase in the stress in the anterior horn of the medial meniscus, and the stress in the anterior horn and body of the lateral meniscus also increases. The stress on the lateral meniscus is not obvious.
5. The stress of medial and lateral tibiofemoral cartilage increased with the increase of flexion, the stress of medial tibiofemoral cartilage decreased with the increase of flexion, and the stress of medial tibiofemoral cartilage decreased with the increase of flexion.
research conclusion
1. The method of measuring the displacement and rotation of tibiofemoral joint by biplane X-ray technique is established. It is proved that the technique is effective and feasible.
2. During knee flexion from extension to 120 degrees, ACL rupture mainly changes the anterior and posterior movement of the lateral condyle of the femur, causing the lateral condyle to loosen backwards in the early flexion range, and causing the lateral condyle to move backwards in the middle of the flexion process significantly less than the normal knee.
3. Between extension and flexion of the knee joint, ACL rupture mainly changes the stress distribution of the tibiofemoral medial compartment, causing the stress of the anterior and posterior horns of the medial meniscus to be significantly greater than that of the normal knee in the extension and flexion positions, and causing the stress of the medial femoral cartilage to increase with the deepening of flexion.
【学位授予单位】：第三军医大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：R686.5
【参考文献】
相关期刊论文 前4条
1 姚杰;樊瑜波;张明;李德玉;宫赫;;前交叉韧带损伤的继发性生物力学影响[J];力学学报;2010年01期
2 汪田福;郝智秀;高相飞;;前交叉韧带生物力学特性及其损伤对膝关节稳定性的影响[J];清华大学学报(自然科学版);2010年07期
3 冯华;张辉;郭铁能;王满宜;;膝关节前十字韧带切断对内侧半月板后角应力的影响[J];中华骨科杂志;2006年07期
4 王岩,周飞虎,周勇刚,崔建;国人正常膝关节三维几何形态测量及相关研究[J];中国矫形外科杂志;2004年08期
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