CroweⅠ型发育不良髋臼月状面三维形态学分型及髋臼周围截骨术的有限元研究

发布时间：2018-05-10 06:54

本文选题：发育性髋关节发育不良 + 髋臼软骨　；参考：《吉林大学》2017年博士论文

【摘要】：目的意义:髋关节发育不良是引起青少年和成人髋关节疼痛和关节炎的一个重要病因。髋臼周围截骨术通过重定位髋臼来为股骨头提供理想的骨性覆盖,广泛用于治疗轻度髋臼发育不良患者。但是即使在足够年轻时行髋臼周围截骨术治疗,有部分患者短期内也可能进展为骨关节炎。这可能由众多原因导致,其中针对发育不良髋臼月状面软骨的研究逐渐引起重视。髋臼周围截骨术重点在如何确定髋臼截骨块的最适旋转角度,增加股骨头一个部位的覆盖率可能会使股骨头另一个部位覆盖率低于正常,然而任何方向的过度覆盖又将导致股骨髋臼撞击。所以术前掌握髋臼负重面即月状面的精确三维信息至关重要。三维有限元分析技术近年来越来越多的应用于髋臼周围截骨术治疗髋关节发育不良的生物力学试验中,通过对术前与术后髋臼软骨等的接触应力分析,预估术中矫正度数的范围,提高手术操作的精确程度。本研究将基于Crowe I型女性髋关节发育不良患者CT数据对髋臼月状面进行三维重建,精确测量,并根据不同方向缺损对髋臼软骨进行形态学分型,通过对不同缺损类型软骨模型的有限元技术分析,验证本分型的理论意义及探索术中髋臼截骨块最适旋转角度,为治疗发育性髋关节发育不良及探讨髋关节骨性关节炎的发生发展机制提供有价值的临床和理论依据。材料与方法:发育不良组67个髋和正常组61个髋均接受标准前后位骨盆X线片和伪侧位X线片、三维CT扫描。骨盆正位片测量LCEA、AI,伪侧位片测量ACEA。将CT数据以DICOM格式导入Mimics及3-matic软件中对正常和发育不良髋臼月状面进行形态学比较。正常骨盆CT数据用Mimics软件对骨盆和股骨近端三维重建,导入MSC.Marc有限元分析软件,划分面网格与体网格,生成一个具有骨盆皮质骨、松质骨、髋臼软骨、髋臼盂唇、股骨头软骨、股骨头皮质骨松质骨、骶髂关节和耻骨联合的正常髋有限元模型,均被定义为各向同性线性弹性材料,共600,000左右个四面体单元,120,000左右个节点。髋臼软骨除去髋臼切迹后表面积为2070.1mm2。关节面定义为非线性、无摩擦的三维接触模型。根据文献赋予不同组织不同的弹性模量和泊松比。通过对正常髋关节有限元模型髋臼缘向后内侧缩进和赋予不同月状面缺损的软骨模型,生成DDH-1 normal、DDH-2 SD、DDH-3ASD和DDH-4 GD模型,分别以10°、15°、20°行髋臼周围截骨术旋转髋臼截骨块得到PAO-1 Normal 20、PAO-1 Normal 25、PAO-1 Normal 30;PAO-2 SD20、PAO-2 SD 25、PAO-2 SD 30;PAO-3 ASD 20、PAO-3 ASD 25、PAO-3 ASD30;PAO-4 GD 20、PAO-4 GD 25、PAO-4 GD 30,共16个有限元模型。在骶骨上关节面中心处,施加一个垂直向下的重力约为620N,外展肌力为460N。以force control作为数值计算方案,采用Newton-Raphson迭代方法分20步逐渐增量加载负荷。研究结果:将DDH组分为上方面积减小组(10.44%)、前上方面积减小组(40.3%)、整体面积减小组(32.84%)和整体面积增加组(16.42%)。发育不良髋臼月状面在骨盆中的三维位置较正常者偏向内下旋转。整体DDH组月状面相对和绝对面积较正常组显著减小。针对DDH各分组术前术后的有限元分析结果,表明在正常髋关节髋臼侧,von Mises应力均匀的分布在月状面的上方区域,大部分集中于髋臼月状面的中心。峰值应力为13.06 MPa。然而,4个DDH模型术前von Mises分布密集的集中在髋臼边缘,DDH-1normal模型,术前峰值应力为24.14 MPa,PAO旋转10°、15°、20°术后峰值应力分别为22.87 MPa、18.94 MPa、19.64MPa。DDH-2 SD模型,术前峰值应力为40.36 MPa,PAO术后峰值应力分别为35.56 MPa、33.22MPa、29.45 MPa。DDH-3 ASD模型,术前峰值应力为43.35 MPa,PAO术后峰值应力分别降低至40.34 MPa、37.99 MPa、30.79 MPa。DDH-4 GD模型,术前峰值应力为46.67 MPa,PAO术后峰值应力分别降低至35.81 MPa、36.28 MPa、30.10 MPa。研究结论:本试验通过对DDH患者髋臼月状面三维重建,精确测量,首次将髋臼月状面分为:上方面积减小型、前上方面积减小型、整体面积减小型和整体面积增加型。有限元分析表明,即使术前放射线学参数一致,但是不同类型髋臼月状面缺损模型术前及术后矫正度数的不同,其髋臼侧接触应力的分布也不尽相同,这为验证分型的临床意义和对PAO术中髋臼截骨块的精确旋转再定位、个体化截骨提供了非常重要的理论依据,同时对于DDH髋关节骨关节炎发生发展机制的研究和保证良好的长期疗效及预防骨关节炎的进展有重要的临床意义。
[Abstract]:Objective: dysplasia of the hip is an important cause of hip pain and arthritis in adolescents and adults. Peri acetabular osteotomy provides an ideal bone cover for the femoral head by repositioning the acetabulum to treat patients with mild acetabular dysplasia. Some patients may also advance to osteoarthritis in the short term. This may be caused by a number of reasons, of which research on the dysplasia of the acetabular moon cartilage is becoming more and more important. The focus of the acetabular osteotomy is to determine the optimum rotation angle of the acetabular osteotomy block, and the increase of the coverage rate of the one part of the femoral head may cause the femoral head to make the stock. The cover rate of the other part of the bone is lower than that of the normal, but the over coverage of any direction will lead to the impact of the femur acetabulum. Therefore, it is essential to master the accurate three-dimensional information of the acetabular weight surface, that is, the monthly surface, and the three-dimensional finite element analysis technique is used in the treatment of hip dysplasia in the treatment of hip joint osteotomy in recent years. In the biomechanical test, the range of preoperative and postoperative acetabular cartilage contact stress analysis is used to predict the extent of correction in the operation and to improve the accuracy of operation. This study will be based on the three dimensional reconstruction of the acetabular moon surface based on the CT data of the Crowe I female hip dysplasia. The morphological classification of acetabular cartilage was carried out. Through the finite element analysis of the cartilage model of different types of defects, the theoretical significance and the optimal rotation angle of the acetabular osteotomy block were explored to provide valuable clinical treatment for developmental dysplasia of the hip and the mechanism of the development of the osteoarthritis of the hip joint. Materials and methods: 67 hip and 61 hips in 67 hips and normal groups in the dysplasia group received standard anterior and posterior X ray films and pseudoralateral X ray films, three-dimensional CT scan. Pelvic positive tablets were measured by LCEA, AI, and pseudo lateral radiograph was used to measure CT data in DICOM format into Mimics and 3-matic software for normal and dysplasia acetabular lunar surface. Morphological comparison. Normal pelvic CT data were reconstructed by Mimics software for three-dimensional reconstruction of the pelvis and proximal femur. MSC.Marc finite element analysis software was introduced to divide surface meshes and body meshes to produce a pelvic cortical bone, cancellous bone, acetabular cartilage, acetabular labia, femoral head cartilage, femoral head cortical bone, sacroiliac joint and pubic bone. The finite element model of the normal hip is defined as an isotropic linear elastic material, with a total of about 600000 tetrahedral elements and about 120000 nodes. The acetabular cartilage is defined as a nonlinear, frictionless, three-dimensional contact model after the acetabular cartilage is removed from the acetabular notch. The different modulus of elasticity is given to different tissues according to the literature. Poisson ratio. The DDH-1 normal, DDH-2 SD, DDH-3ASD and DDH-4 GD models were generated by indentation of the acetabular edge of the finite element model of the normal hip joint and endowed with different lunar surface defects. The acetabular osteotomy block around the acetabulum was rotated by the acetabular osteotomy for PAO-1 Normal 20, PAO-1 Normal 25 and PAO-1 30, respectively, by the 10 degrees, 15 degrees, and 20 degrees respectively. AO-2 SD20, PAO-2 SD 25, PAO-2 SD 30; PAO-3 ASD 20, PAO-3 ASD 25, PAO-3 ASD30; 20, 25, 30, a total of 16 finite element models. The method was divided into 20 step incremental loading load. The results were divided into group DDH subtraction group (10.44%), area reduction group (40.3%), total area reduction group (32.84%) and overall area increase group (16.42%). The three dimensional position of dysplastic acetabular surface in pelvis was more than normal people, and the overall DDH group was monthly. According to the results of the finite element analysis of the DDH groups before and after the operation, it was shown that the stress of the von Mises was evenly distributed over the upper part of the lunar surface at the acetabular side of the normal hip joint. The peak stress was 13.06 MPa., but the von Mises distribution before the 4 DDH models. Concentrated concentration at the acetabular edge, DDH-1normal model, the peak stress of 24.14 MPa, PAO rotation 10, 15, 20 degrees, 22.87 MPa, 18.94 MPa, 19.64MPa.DDH-2 SD model, pre operation peak stress of 40.36 MPa, and peak stress of 35.56 MPa, 33.22MPa, 29.45 MPa.DDH-3 model, peak stress. For 43.35 MPa, the peak stress after PAO was reduced to 40.34 MPa, 37.99 MPa, and 30.79 MPa.DDH-4 GD model, the peak stress was 46.67 MPa, and the peak stress after PAO was reduced to 35.81 MPa, 36.28 MPa, 30.10 MPa.. The size of the upper area was reduced, the area of the anterior upper area was reduced, the overall area was reduced and the overall area was increased. The finite element analysis showed that, even if the preoperative radiological parameters were consistent, the distribution of the acetabular side contact stress in the acetabular model of different types of acetabular models was different, which was proved to be different. The clinical significance of the classification and the accurate rotation and repositioning of the acetabular osteotomy block in PAO provides a very important theoretical basis for the individualized osteotomy. At the same time, it has important clinical significance for the study of the pathogenesis and development mechanism of the osteoarthritis of the hip joint in DDH and the good long-term effect and the prevention of osteoarthritis.

【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R684

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