Maxian T A, Brown T D, Pedersen D R, Callaghan J J
Department of Orthopaedic Surgery, University of Iowa, Iowa City 52240, USA.
J Orthop Res. 1996 Jul;14(4):668-75. doi: 10.1002/jor.1100140424.
Adaptive remeshing capability was added to an existing sliding-distance-coupled finite element model of polyethylene wear in total hip arthroplasty. This augmentation allowed earlier postoperative wear simulation to be extended to the clinically more significant long-term regimen (as long as 20 years). Loads and femoral head excursions were taken from a physically validated gait analysis model of a patient with an instrumented total hip replacement. For otherwise identical 22, 28, and 32 mm components, the least volumetric wear but the most linear wear occurred for the 22 mm head. When the polyethylene thickness in a 22 mm component was reduced to the same as that in a 32 mm component, the volumetric wear rate for the 22 mm component was still much less than that for the larger component, indicating that sliding distance (head size), rather than polyethylene liner thickness, was primarily responsible for the difference in rates. A "28 mm" series, for which head sizes were varied across the range of currently accepted industrial tolerances, showed that although initial wear rates were greatest for the least congruent articulations, the long-term volumetric wear was nearly the same, regardless of initial clearance.
在现有的全髋关节置换术中聚乙烯磨损的滑动距离耦合有限元模型中增加了自适应网格划分功能。这种增强使得术后早期磨损模拟能够扩展到临床上更具意义的长期情况（长达20年）。负荷和股骨头偏移量取自一个带有仪器的全髋关节置换患者的经过物理验证的步态分析模型。对于其他条件相同的22毫米、28毫米和32毫米部件，22毫米股骨头的体积磨损最小，但线性磨损最大。当22毫米部件中的聚乙烯厚度减小到与32毫米部件中的相同时，22毫米部件的体积磨损率仍远低于较大部件的，这表明滑动距离（股骨头尺寸）而非聚乙烯衬垫厚度是造成磨损率差异的主要原因。一个“28毫米”系列，其股骨头尺寸在目前公认的工业公差范围内变化，结果表明，尽管初始磨损率在一致性最差的关节中最高，但无论初始间隙如何，长期体积磨损几乎相同。
