半髋关节假体的有限元分析

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3.0 侯斌 2024-11-19 5 4 2.97MB 56 页 15积分

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摘要

髋关节置换术是治疗股骨头坏死、创伤性关节炎、类风湿性关节炎等髋关节

疾病的有效方法，但术后常常出现假体松动现象，引起假体松动的主要原因有力

学因素和生物因素，所以术后髋关节的应力分布和假体松动机理的研究引起广大

学者的关注。有限元分析是一种研究生物力学的有效方法，广泛用于假体结构设

计。本文利用有限元分析对新型髋关节假体材料—碳材料，在半髋置换术中的应

用进行了研究。根据近年来髋关节置换术的发展，以及在特定的历史条件下，该

碳材料先于基础研究而直接应用于临床所取得的优异效果，做了以下工作：

首先，针对半髋置换术术后髋臼出现的近期疼痛与远期磨穿现象，采用非线

性有限元方法，建立了半髋置换术髋臼—股骨头假体的有限元模型，模拟人体步

态中完全负重的情况进行静态加载，研究髋臼的应力分布。研究结果表明，不同

弹性模量的假体头材料，对髋臼应力各不相同，弹性模量越大，髋臼应力越大，

应力主要分布在髋臼外上侧。

其次，组合式假体接触部位的磨损是导致假体松动的主要原因之一。本研究

采用 ANSYS11.0 对股骨头假体与颈部接触部位进行接触分析，研究接触部位的微

动磨损状况。通过分析可以看出：颈材料为钛合金时，随着头材料（碳材料、复

合材料（CFR/PSF）、氧化锆陶瓷）弹性模量和表面摩擦系数的增加，相对位移和

接触应力都呈下降趋势。对于碳材料假体头，刚度较大的钴铬钼合金与钛合金颈

相比，产生的相对位移较小，但接触应力较大。

最后，为进一步研究假体体内植入情况，我们采用吉林中心医院设计的兔股

骨头假体进行动物植入实验，对其生物相容性以及疲劳磨损情况进行了初步观察。

目前结果显示，碳材料不会引起明显的炎症反应，没有明显的磨损，生物相容性

较好。

本文通过计算机仿真和动物试验，并结合临床随访，对碳质股骨头假体半髋

置换术进行较全面的分析，结果表明，采用碳—钛组合式假体进行半髋置换术，

生物力学及组织相容性均较好，短期未出现明显的炎症和疲劳磨损。

关键字：半髋置换术，碳材料，髋关节，有限元分析，接触分析

ABSTRACT

Hip joint replacement is an effective method to cure the Femoral head necrosis,

Traumatic Arthritis, Rheumatoid Arthritis and other hip joint diseases, but the implant

loosening always takes place after the surgery. There are two main reasons for the

loosening: abnormal stress distribution and biological reaction. So the stress distribution

of hip joint after operation and the mechanism of biological reaction have got many

researchers’ attention. Finite element analysis is a useful method to investigate the

biological stress. It is widely used in the design of prothesis, such as investigating the

effect of geometry and the material mechanics property, both of which influence the

stress distribution of the hip joint. The innovation of this paper is that using finite

element analysis to study the carbon prothesis used for hip hemi-arthroplasty (HHA).

According to the development of hip joint replacement in the recent years and the good

effects of carbon prothesis using in the clinic without the necessary scientific

investigation in the special early history period, the following work had been carried out

in this research:

First, as after the replacing operation there always are a lot of pain and even wore

out in the acetabular cup, the finite element model of the HHA were established to

analyze the stress condition of the acetabular with different implant femoral head

materials. The model simulated the complete sustain conditions during normal gait with

static load. The results showed that the different elastic modulus of materials caused

quite different stress distributions on the acetabular. The bigger of materials’ elastic

modulus were, the bigger of stress would be on the acetabular. The position of stress

mainly located on the lateral acetabular.

Secondly, the wear of contact parts, the femoral head and the stem neck, always

leads to the loosening of prosthesis and other bad issues, so the model of femoral head

contacting with the stem neck was built up by ANSYS 11.0. The following conclusion

was achieved: as the increasing of the stiffness and surface friction coefficients of the

femoral head, the relative displacement and contact stress both decreased.

Finally, the animal implantation experiments were carried out to observe the

biocompatibility and fatigue wear conditions. The implants were designed by the expert

of Central hospital of Jilin and implanted in the rabbits. Present results showed that

carbon material would not cause obvious inflammatory response. There was no obvious

wear phenomena and had good biocompatibility.

This investigation provided a general analysis of the carbon femoral head used in

the HHA surgery. It showed that HHA with carbon-titanium implant had excellent

performance. There was no significant inflammation and wear debris in the experiments.

Both of the biocompatibility and mechanical compatibility of this material were fairly

well.

Kay words: Hip hemi-arthroplasty, Carbon material, Hip joint, Finite

element analysis, contact analysis

摘要

ABSTRACT

第一章绪论 .....................................................................................................................1

§1.1 引言 ....................................................................................................................1

§1.2 髋关节结构和生物力学 ....................................................................................2

§1.2.1 髋关节结构 ...............................................................................................2

§1.2.2 髋关节生物力学 .......................................................................................2

§1.3 髋关节置换术的发展和现状 ............................................................................3

§1.4 目前存在的问题及解决措施 .............................................................................7

§1.5 课题研究目的、内容和意义 ...........................................................................10

§1.6 本章小结 ..........................................................................................................10

第二章有限元分析理论与应用 ...................................................................................12

§2.1 有限元分析原理 ...............................................................................................12

§2.2 基于 ANSYS 的接触问题分析 ....................................................................... 13

§2.3 有限元在髋关节置换术中的应用 ...................................................................16

§2.3.1 髋臼的有限元分析 ................................................................................. 16

§2.3.2 股骨头的有限元分析 ............................................................................. 16

§2.3.3 髋关节假体柄的有限元分析 ................................................................. 17

§2.4 本章总结 ...........................................................................................................18

第三章假体头-臼有限元接触分析 ............................................................................. 19

§3.1 引言 ...................................................................................................................19

§3.2 材料与方法 .......................................................................................................19

§3.2.1 假体头与髋臼接触模型的建立 ...............................................................19

§3.2.2 碳材料属性 ...............................................................................................20

§3.2.3 划分网格 ...................................................................................................21

§3.2.4 施加载荷和约束 .......................................................................................22

§3.2.5 计算求解 ...................................................................................................23

§3.3 不同假体材料应力对比 ...................................................................................26

§3.4 假体尺寸对应力的影响 ...................................................................................27

§3.5 本章总结 .......................................................................................................... 27

第四章头颈微动磨损接触分析 ...................................................................................28

§4.1 引言 ..................................................................................................................28

§4.2 材料与方法 ......................................................................................................28

§4.2.1 几何模型的建立 .......................................................................................28

§4.2.2 材料特性 .................................................................................................. 28

§4.2.3 三维有限元模型 .......................................................................................29

§4.2.4 边界条件及载荷 ......................................................................................29

§4.3 结果与讨论 .......................................................................................................29

§4.3.1 微动损伤理论 .......................................................................................... 29

§4.3.2 假体头颈系统相对位移及接触应力 .......................................................30

§4.3.3 假体材料对微动磨损的影响 ...................................................................32

§4.4 本章总结 ..........................................................................................................33

第五章碳材料假体动物实验与临床随访 ...................................................................34

§5.1 引言 ...................................................................................................................34

§5.2 碳材料疲劳特性的动物试验 ...........................................................................34

§5.3 临床随访 ...........................................................................................................40

§5.4 本章总结 ...........................................................................................................40

第六章总结与展望 .......................................................................................................41

6.1 全文总结 .............................................................................................................41

6.2 本文主要创新点 .................................................................................................41

6.2 工作展望 .............................................................................................................42

参考文献 .........................................................................................................................43

在读期间公开发表的论文和承担科研项目及取得成果 .............................................49

附录 .................................................................................................................................49

致谢 .................................................................................................................................53

第一章绪论

§1.1 引言

近年来由于疾病、工伤、交通事故以及肥胖人数的增加等导致髋关节疾病患

者人数正以惊人的速度增加，如股骨颈骨折、股骨头坏死、骨性关节炎、风湿及

类风湿性关节炎、强直性脊柱炎等。目前髋关节置换术是治疗这些髋关节疾病的

有效方法，据统计,全球每年约有80 万例髋关节置换者,并呈现逐年递增的趋势

[1-3]，图1-1为髋关节置换术示意图。最早的髋关节置换手术出现于19世纪，至今已

有近百年发展历史，但是直至1962年，Chamley提出骨水泥应用来固定假体后，金

属假体的稳定性才得以实现[6]，但髋关节置换术术后假体松动一直是髋关节置换术

发展过程中的最大障碍。首先磨屑是引起假体松动的重要原因之一。假体材料与

骨界面间的微动摩擦会产生磨损颗粒，磨损颗粒随关节液通过有效关节间隙远离

关节向假体周围扩散，加剧假体和关节磨损，并引起假体周围骨溶解，导致假体

的松动[5]。其次，由于假体的植入而导致髋关节应力分布发生很大的改变，造成应

力遮挡，即股骨的应力在髋关节置换后发生很大改变，假体植入后承担大部分的

应力，从而造成某些区域骨质应力减少，特别是股骨近端区域[6]。根据Wolf定律，

骨质会根据变化的生物力学环境进行适应性骨重建，并通过骨质吸收作用引起部

分骨质的丢失。骨质吸收有可能引起假体的松动，在年轻患者中这种情况尤为显

著。出现骨质重建的根本原因是假体植入髓腔后股骨近端的负荷传导和生物力学

环境的改变。因此，研究髋关节置换术后假体微动磨损和股骨侧应力水平及其分

布的变化很有必要，对于优化假体设计、分析假体失败原因、临床治疗选择以及

并发症的预防等方面均有重要的实际意义。

图1-1 髋关节置换术示意图[4]

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摘要：

摘要髋关节置换术是治疗股骨头坏死、创伤性关节炎、类风湿性关节炎等髋关节疾病的有效方法，但术后常常出现假体松动现象，引起假体松动的主要原因有力学因素和生物因素，所以术后髋关节的应力分布和假体松动机理的研究引起广大学者的关注。有限元分析是一种研究生物力学的有效方法，广泛用于假体结构设计。本文利用有限元分析对新型髋关节假体材料—碳材料，在半髋置换术中的应用进行了研究。根据近年来髋关节置换术的发展，以及在特定的历史条件下，该碳材料先于基础研究而直接应用于临床所取得的优异效果，做了以下工作：首先，针对半髋置换术术后髋臼出现的近期疼痛与远期磨穿现象，采用非线性有限元方法，建立了半髋置换术髋臼—股骨头假体的...

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