CroweⅣ型髋关节脱位儿童髋臼有限元生物力学分析

Finite Element Analysis of CroweIV Development Dislocation of the Hip

目的:建立CroweIV型发育性髋关节脱位儿童骨盆三维有限元模型,对发育性髋关节脱位儿童真性髋臼及假性髋臼的生物力学进行初步分析。方法:采用单侧发育性髋关节脱位儿童骨盆CT扫描DICOM数据,通过Mimics10.0对图像DICOM数据进行重建,经Geomagic Proe5.0进行网格优化,在Hepermesh 10.0中进行有限元网格划分后输入ANSYS12.0中,在ANSYS中根据解剖部位建立骨盆主要韧带,行单腿站立载荷加载,计算该加载方式下骨盆的应力及位移分布情况。结果:模拟患者单腿(患侧)站立状态下身体重心通过假关节的中心,骨盆极度倾斜约45°,给予生理载荷,应力主要集中在假髋臼和骶髂关节面之间,耻骨上肢内侧是应力集中区但是应力小于骶髂关节周围部分;患侧骨盆位移以髂骨翼前侧向后侧逐渐减弱。结论:建立的有限元模型在静载荷下特征部位的应力及位移能够反映CroweIV型髋关节脱位儿童骨盆的力学结构特性,模型的准确性高,可以成为CroweIV型髋关节脱位儿童骨生物力学研究的工具,满足临床研究需要。

Objective： To construct a three-dimensional（3D） finite element pelvic model of child with Crowe IV developmental dislocation of the hip（DDH）,and to investigate the stress around pseudo-acetabular and acetabular of DDH.Methods： One ten-year-old girl with DDH was scanned by multi-slices computerized tomography（MSCT） and the images of every cross-section were obtained.The three-dimensional images of the DDH child pelvis were reconstructed with the software Mimics 10.0.The three-dimensional model of the pelvis was imported into the ANSYS12.0 by the Geomagic Proe 5.0 and the Hempermesh 10.0.Digital three-dimensional structures of the DDH child pelvis,such as ligament,were added to the three-dimensional model with powerful pre-processing modular of ANSYS.Finally,the integrated three-dimensional finite elemental model of the DDH child pelvis was established.The boundary and loading conditions used Single-leg stance.The stress,strain and displacement nephogram were obtained under axial load.Results： Simulation patient standing on one leg with the physiological load,pelvis tilted by about 45°,and the distributions of von Mises stress was mainly between false acetabulum and sacroiliac joint surface.Pubic upper medial was also the stress concentration zone where the stress is less than the sacroiliac joint part.The distributions of displacement were from the iliac wing front side gradually weakened.Conclusions： The children pelvic finite element model of Crowe IV type development dislocation of the hip is valid and reasonable,which can be the biomechanics research tools to meet the needs of clinical research.