Biomechanics of osteonecrosis of femoral head after tantalum rod implantation: a three-dimensional finite element analysis

doi:10.3969/j.issn.2095-4344.2017.31.011

Abstract

Abstract:

BACKGROUND: The femoral anterolateral column plays a key role in hip preservation surgery, and the China-Japan Friendship Hospital (CJFH) type stresses the anterolateral column, but there is little information available in three-dimensional (3D) finite element analysis of the L-type tantalum rod implantation.

OBJECTIVE: To establish a 3D finite element model of L-type tantalum rod implantation into the normal, necrotic and L-type necrotic areas, followed by a finite element analysis, and to explore the importance of the integrity of the anterolateral column for hip preservation surgery, thus providing biomechanical evidence for the treatment of CJFH type.

METHODS: Based on the prepared 3D models of CJFH L1, L2 and L3 osteonecrosis of the femoral head (ONFH) and normal hip, the 3D finite element model of tantalum rod implantation of femoral head necrosis was established, and finite element analysis was conducted. The stress distribution and the maximum Mises stress value of cortical shell of normal femoral head, necrotic femoral head and tantalum rod implanted ONFH were observed and compared.

RESULTS AND CONCLUSION: (1) The maximum Mises of the weight-bearing area of cortical bone shell of L-type ONGH was higher than that of normal femoral, L1. L2 and L3 increased by 21.76%, 31.02%, and 42.79%, respectively. (2) The maximum Mises of weight-bearing area of cortical bone shell was decreased after tantalum rod implantation, L1 L2 and L3 decreased by 13.38%, 8.81%, and 11.45%, respectively. (3) In necrotic femoral head, the decreased bearing stress, leads to stress concentration on the femoral head bone shell, so the maximum is higher than that of the normal condition. The higher classification is, the greater the stress concentration of the cortical bone shell is. Tantalum rod implantation share certain stress. (4) Tantalum rod implantation corrects some stresses of the bone shell of ONFH, and can prevent collapse and exert the biomechanical effect of supporting subchondral bone. Furthermore, the integrity of the lateral column of the necrotic femoral head affects the efficacy of hip preservation, and more lateral column preserved always accompanied with better hip preservation. The higher CJFH classification exhibits a higher risk of collapse, and poorer hip preservation.

中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程

Key words: Femoral Head Necrosis, Finite Element Analysis, Biomechanics, Tissue Engineering

CLC Number:

R318

Ou Zhi-xue, Ling Guan-han, Yao Lan, Lin Heng-feng. Biomechanics of osteonecrosis of femoral head after tantalum rod implantation: a three-dimensional finite element analysis [J]. Chinese Journal of Tissue Engineering Research, 2017, 21(31): 4983-4988.

Figures/Tables 1

2.1 正常股骨头软骨表面应力结果应用Abaqus6.14软件进行有限元分析，通过von Mises Stress冯米斯应力指标，分析正常、坏死和钽棒置入术股骨头皮质骨壳的von Mises应力峰值，对比分析生物力学效能。应用Abaqus6.14软件进行有限元分析，得出以下图正常股骨头软骨表面的Mises应力图(图5)，最大峰值应力为7.166 MPa。 2.2 正常三维有限元模型有效性验证正常软骨表面的应力结果见图5，最大峰值应力为7.166 MPa，与Von Eisenhart[14]和 Abraham 等[15]研究报道的股骨软骨峰值应力相近。Von Eisenhart等[12]模拟一个步行周期中提供对髋关节不协调和压力的定量数据，用压敏片测量，在站立位时平均最大压力为7.7个步行周期中提供。Abraham等[13]量化软骨接触应力，有限元分析预测较高的峰值接触应力为6.2-9.8 MPa。据此认为本研究所建立三维有限元模型有效，可进行研究。 2.3 股骨头负重区皮质骨壳的Von Mises应力分布正常、坏死、钽棒置入术后股骨头负重区皮质骨壳的最大应力情况见表1。表明L型坏死股骨头负重区皮质骨壳的最大Mises应力都较正常股骨头升高，其中L1型升高21.76%，L2型升高31.02%，L3型升高42.79%；钽棒置入术后股骨头负重区皮质骨壳的最大Mises应力较术前下降，其中L1型下降13.38%，L2型下降8.81%，L3型下降11.45%。 2.4 股骨头负重区皮质骨壳的应力值与统计比较对收集的数据记录在Excel文件中，应用SPSS 19.0软件进行统计分析。 2.4.1 比较L1、L2和L3型坏死股骨头应力值与正常应力值的差异采用两独立样本t 检验分别比较L1、L2和L3型坏死股骨头应力值与正常应力值的差异。L1、L2、L3型坏死股骨头应力值与正常组应力值差异均无显著性意义(P > 0.05)，见表2。 2.4.2 比较L1、L2和L3型钽棒置入坏死股骨头应力值与正常应力值的差异采用两独立样本t 检验分别比较L1、L2和L3型钽棒置入坏死股骨头应力值与正常应力值的差异。L1、L2、L3型钽棒置入坏死股骨头应力值与正常组应力值差异均无显著性意义(P > 0.05)，见表3。 2.4.3 比较L1、L2和L3型坏死股骨头应力值与钽棒置入后应力值的差异采用配对样本t 检验分别比较L1、L2和L3型钽棒置入坏死股骨头应力值与L1、L2和L3型坏死股骨头应力值的差异。L1型钽棒置入坏死股骨头应力值与L1型坏死股骨头应力值差异有显著性意义(P < 0.05)，从均值来看，L1型坏死股骨头应力值高于L1型钽棒置入坏死股骨头应力值。L2型钽棒置入坏死股骨头应力值与L2型坏死股骨头应力值差异有显著性意义(P < 0.05)，从均值来看，L2型坏死股骨头应力值高于L2型钽棒置入坏死股骨头应力值。L3型钽棒置入坏死股骨头应力值与L3型坏死股骨头应力值差异有显著性意义(P < 0.05)，从均值来看，L3型坏死股骨头应力值高于L3型钽棒置入坏死股骨头应力值。钽棒置入L1型的坏死股骨头的皮质骨壳的应力下降幅度最大(P < 0.001)，L2型坏死股骨头次之(P < 0.008)，L3型坏死股骨头下降幅度最小(P < 0.01)，见表4。 2.4.4 比较L1、L2、L3型的正常组、坏死组、钽棒置入组应力值的差异采用方差分析比较L1、L2、L3型的正常组、坏死组、钽棒置入组应力值的差异。L1、L2、L3型的正常组、坏死组、钽棒置入组应力值差异均无显著性意义(P > 0.05)，见表4。 "

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