中文摘要：

目的通过有限元磨损模型研究上楼梯对衬垫磨损的影响，对完善人工膝关节的磨损评估方法、指导假体设计等具有重要的理论和实际意义。方法基于Archard磨损理论建立人工膝关节衬垫磨损的有限元模型并验证，然后加载正常水平行走（IS014243标准）和上楼梯的载荷，对比分析上楼梯对衬垫磨损的影响。结果水平行走步态载荷下，模型预测的磨损结果与文献实验报道结果一致，模型具有较好的有效性。上楼梯的体积磨损率为每100万次循环（millioncycle，MC）37．10mm^3，显著高于水平行走步态的体积磨损率（16．94mm^3／MC），线性磨损也具有类似的结果。上楼梯内侧平台的磨损区域主要集中在后部，与水平行走时内侧平台的磨损主要发生在中部区域有明显不同。结论上楼梯作为高载荷、高屈膝角度的日常运动之一，对人工膝关节衬垫的磨损有较大影响，其磨损率和磨损区域与水平行走有明显差异，在人工膝关节的磨损检测和评估中应该给予适当的重视。

英文摘要：

Objective To study the effect of stair ascent on insert wear of total knee replacement （TKR） by finite element model, which is of great theoretical and practical significance for improvement of wear evaluation method and guidance of artificial knee joint prosthesis design. Methods A finite element model of TKR wear based on Archard＇s law was established and validated. The model was applied with loads under normal level walking （ISO14243） and stair ascent, respectively, to compare and analyze the influence of stair ascent on TKR wear. Results The predicted wear during level walking was consistent with experimental results reported in the litera- ture. The volumetric wear rate during stair ascent was 37. l0 mm3 per million cycle （MC）, which was significantly higher than that during level walking （ 15.94 mm3/MC）. The linear wear during stair ascent was significantly high- er than that during level walking as well. Wear during stair ascent was mainly distributed in the backward area of the medial platform, which was obviously different from that during level walking. Conclusions As a common dai- ly activity with high loads and high flexion angles, stair ascent has a significant effect on TKR wear, and more at- tention should be paid to the testing and evaluation of TKR wear.