Coulomb frictional interfaces in modeling cemented total hip replacements: a more realistic model.
Coulomb frictional interfaces in modeling cemented total hip replacements: a more realistic model.
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DOI：
10.1016/0021-9290(94)00158-z
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发表时间：
1995-09
影响因子：
2.4
通讯作者：
Kenneth A. Mann;Donald L. Bartel;Timothy M. Wright;A. H. Burstein
中科院分区：
文献类型：
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作者：
Kenneth A. Mann;Donald L. Bartel;Timothy M. Wright;A. H. Burstein
骨水泥型髋关节假体的松动可能是由于骨水泥应力过高而导致的骨水泥外套膜的破坏。这项研究的目的是确定与粘结的茎-水泥界面相比，真实的茎-水泥界面特性是否会导致高的水泥应力，并确定是否可以选择茎设计参数来降低峰值水泥应力。采用粘结型或真实型库仑摩擦假体-骨水泥界面，建立了骨水泥假体的三维有限元模型。结果表明，使用非粘结的、非线性的库仑摩擦界面，与使用粘结的杆-水泥界面相比，水泥中的应力场有很大的不同。库仑摩擦界面壳的近端水泥台架上的拉应力(10.8 Mpa)大于水泥的疲劳强度。相反，水泥套中的拉应力不大于粘结外壳的疲劳强度(7.5 Mpa)。因此，股骨近端的骨水泥外套层的破坏可能是由于骨柄-骨水泥界面缺乏粘结剂所致。对于具有库仑摩擦界面的模型，还评估了不同横截面形状(内径为3.0、4.9和5.5 mm，前后宽度为9.8和13.7 mm)和不同弹性系数(钴铬合金和钛合金)对柄材料的影响。骨柄横截面和弹性模量值的变化对骨水泥中的应力分布影响有限。在本研究中评估的参数中，茎-水泥界面的特性对水泥盖应力的影响最大。
Loosening of cemented femoral hip stems could be initiated by failure of the cement mantle due to high cement stresses. The goals of this study were to determine if realistic stem-cement interface characteristics could result in high cement stresses when compared to a bonded stem-cement interface and to determine if stem design parameters could be chosen to reduce peak cement stresses. Three-dimensional finite-element models of cemented femoral hip components were studied with bonded or realistic Coulomb friction stem-cement interfaces. The results showed that the use of a non-bonded, non-linear Coulomb friction interface resulted in substantially different stress fields in the cement when compared to a bonded stem-cement interface. Tensile stresses in the proximal cement mantel for the Coulomb friction interface case (10.8 MPa) were greater than the fatigue strength of the cement. In contrast, the tensile stresses in the cement mantle were not greater than the fatigue strength for the bonded case (7.5 MPa). Failure of the cement mantle in the proximal femur could therefore be initiated by a lack of a bond at the stem-cement interface. The effect of different cross-sectional stem geometries (medial radii of 3.0, 4.9 and 5.5 mm and antero-posterior widths of 9.8 and 13.7 mm) and different elastic moduli (cobalt chromium alloy and titanium alloy) for the stem material were also evaluated for models with a Coulomb friction interface. Changes in the stem cross-section and elastic modulus had only limited effects on the stress distributions in the cement. Of the parameters evaluated in this study, the characteristics of the stem-cement interface had the largest effect on cement mantle stresses.