针对骨关节炎疾病，人工关节置换术能去除病灶，也能维持人体生理运动，在临床已得到广泛应用。然而在人体复杂生化环境和生理载荷长期作用下，人工关节运动面在摩擦中会产生大量磨屑，已成为引起假体无菌性松动的主要因素。本文优化了磨屑分离和特征提取方法，以CoCrMo-UHMWPE为配副材料，系统研究了人工膝关节和人工颈椎间盘2种常见假体在单一滑动和复合运动模式下的磨屑特征，揭示了应力、周期和材料等因素对磨屑特征的影响，并分析了磨屑尺寸、浓度和材料对小鼠成纤维细胞毒性的影响，以期为新型耐磨人工关节设计提供科学依据。首先，针对人工膝关节的CoCrMo-高交联UHMWPE配副，分别在22、35、48和60 MPa的表面接触应力下开展了5万次往复滑动磨损实验，研究了单一滑动模式下不同接触应力对磨屑特征的影响；利用人工膝关节摩擦磨损试验机进行了500万次磨损实验，讨论了复合运动模式下不同磨损周期对磨屑特征的影响。结果表明：（1）单一滑动模式下，表面接触应力越大，磨屑尺寸逐渐减小，磨损机理逐渐由磨粒磨损向粘着磨损过渡；（2）复合运动模式下，随磨损周期增加，磨屑数量先增加后减少，磨屑尺寸主要在5 μm以下；（3）磨屑形态以块状为主，也有球状、片状和带状等；不同形状磨屑尺寸存在差异，块状磨屑尺寸分布在数十微米以下，球状和片状磨屑则多小于1 μm，带状磨屑常为1-5 μm。其次，针对人工颈椎间盘，通过5万次往复滑动磨损实验和20万次体外仿真磨损实验，重点对比了单一滑动模式和复合运动模式下非交联、高交联和抗氧化型UHMWPE三种材料的摩擦磨损性能和磨屑特征。结果表明：（1）单一滑动模式下，非交联UHMWPE的摩擦系数和磨损量最大，但在48 MPa下3种材料磨屑尺寸和数量分布接近，磨屑尺寸范围为0-10 μm；（2）复合运动模式下人工颈椎间盘的UHMWPE磨屑形状分布近似于人工膝关节磨屑，均以块状磨屑为主，并有少量的球状、带状等类型；磨屑尺寸集中在1-5 μm，整体大于人工膝关节磨屑。最后，探究了UHMWPE磨屑尺寸、浓度等对小鼠成纤维细胞生物毒性影响，其中尺寸梯度为纳米级、6 μm、13 μm、25 μm，浓度梯度为0.1 mg/mL、0.5 mg/mL、2.5 mg/mL。细胞增殖率结果表明：（1）纳米级磨屑的细胞毒性显著强于其他尺寸；（2）在一定范围内，磨屑浓度越大，细胞毒性越强。

Artificial joint replacement can treat osteoarthritis and maintain the physiological movement function of human body. It has been widely used in clinic. However, under the long-term impact of the complex biochemical environment and physiological load of the human body, a large amount of wear debris will be produced on the moving surface of the artificial joint during friction, which has become the main factor causing aseptic loosening of the prosthesis. In this paper, the methods of debris separation and feature extraction were optimized. With CoCrMo-UHMWPE as the matching pair, the debris characteristics of two common prostheses, artificial knee joint and artificial cervical intervertebral disc, under single sliding and compound motion modes were systematically studied. The effects of stress, cycle and material on the debris characteristics were revealed, and the effects of debris size, concentration and material on cytotoxicity of mouse fibroblasts were analyzed. This paper is aim to provide scientific basis for the design of new wear-resistant artificial joint.Firstly, 50000 reciprocating sliding wear tests were carried out under four surface contact stresses of 22 MPa, 35 MPa, 48 MPa and 60 MPa respectively for the CoCrMo-high-crosslinked UHMWPE matching pair of artificial knee joint, and the effects of different contact stresses on the characteristics of wear debris under a single sliding mode were studied. Five million wear tests were carried out on the artificial knee joint friction and wear tester, and the effects of different wear cycles on the characteristics of wear debris under the compound motion mode were discussed. The results show that: (1) Under the single sliding mode, the larger the surface contact stress is, the smaller the friction coefficient and the debris size are, and the wear mechanism gradually transits from abrasive wear to adhesive wear. (2) In the compound motion mode, with the increase of wear cycle, the number of debris first increases and then decreases, and the size of debris is mainly 5 μm or less. (3) The morphology of wear debris includes granule, ball, flake and fiber. There are significant differences in the size of different shapes of debris. The size of granular debris ranges from hundreds of nanometers to tens of microns, while the size of spherical and flake-like debris is mostly less than 1 μm. And the size of fibrillar debris is mostly between 1 to 5 μm.Secondly, for the artificial cervical intervertebral disc, through 50000 reciprocating sliding wear tests and 200000 in vitro simulation wear tests, the friction and wear properties and debris characteristics of non-crosslinked, high-crosslinked and antioxidant UHMWPE materials under single sliding mode and compound motion mode were compared. The results show that: (1) Under single sliding mode, the friction coefficient and wear loss of non-crosslinked UHMWPE are the largest, but the size and quantity distribution of the three materials are similar under 48 MPa, and the size of most wear debris is under 10 μm. (2) The shape and distribution of UHMWPE debris of artificial cervical intervertebral disc under compound motion mode are similar to that of artificial knee joint debris, which are mainly granular debris, with a small number of spherical and fibrillar debris. The size of wear debris is concentrated in 1-5 μm and larger than the debris from artificial knee joint.Finally, the effects of the size and concentration of UHMWPE debris on the cytotoxicity of mouse fibroblasts were investigated, in which the size gradients were nanoscale, 6 μm, 13 μm, 25 μm and the concentration gradients were 0.1 mg/mL, 0.5 mg/mL and 2.5 mg/mL. The results of cell proliferation rate showed that: (1) The cytotoxicity of nanoscale debris was significantly stronger than that of other sizes. (2) In this certain range, the higher the concentration of debris, the stronger the cytotoxicity.