兔用金属对金属表面人工膝关节假体置入的可行性

背景：目前抗磨损方面的研究主要集中在关节摩擦副的改进和选择，其中金属对金属摩擦副是重要的革新与探索方向之一。 目的：观察兔用金属对金属表面人工膝关节假体置入动物体内的可行性及置入后12个月的使用情况，并探讨其生物力学性能。 方法：自行设计完成兔膝关节假体，人工股骨和人工胫骨假体表面均为不锈钢材料，使其摩擦表面配对成为金属对金属。10 只成年新西兰大白兔随机分成两组，每组5只，实验组和对照组分别行左侧人工膝关节置换，髌骨不置换，分别置入生物型网孔假体和骨水泥固定的非网孔假体。 结果与结论：置换后12个月，实验组标本大体观察可见大量骨质重建现象；两组膝关节功能差异无显著性意义；X射线检测示两组均固定良好，无脱位及松动发生；生物力学测试假体骨界面最大剪切强度实验组明显高于对照组(P < 0.05)；扫描电镜观察实验组假体固定界面可见新骨形成，对照组假体与骨固定界面无新骨形成。提示金属对金属表面人工膝关节，无论是骨水泥假体还是生物型假体，均适合于在动物体内使用，置换后12个月动物实验观察见生物型假体及骨水泥假体在动物体内生存良好，多层网孔表面兔用生物型人工膝关节假体置入动物体内的固定强度要优于骨水泥假体。

Feasibility of metal-on-metal prostheses for total knee arthroplasty in rabbits

BACKGROUND:The present studies of the anti-wear are focused on the improvement and choice of the joint surface. The surface of metal-on-metal is the most important direction of reform and investigation. OBJECTIVE:To explore the feasibility and the utilization information after 12 months of metal-on-metal prosthesis of total knee arthroplasty (TKA) in rabbits and evaluate the biomechanical characteristics of the prosthesis. METHODS:The prostheses were designed personally, surfaces of femoral and tibial prostheses were reformed by stainless steel-mesh, friction surfaces were used to match metal-on-metal. Ten adult New Zealand rabbits underwent TKA and non-replacement of the patella were divided randomly into two groups (5 in each group). The experimental prosthesis was fixed biologically and the control group was used with bone cement. RESULTS AND CONCLUSION: At 12 months after replacement, a great amount of bone reconstructions were found in the experimental group. The difference of function of the knee joint between the two groups was not significant. Roentgenograms proved that two groups were fixed well and no dislocation and no loosening. The maximal shear strength of prosthesis bone interface in the experimental group was higher than that in the control group (P < 0.05).There were new bone formation of the thick stereo mesh surface of the prosthesis in the experimental group and no new bone formation of the surface of the cementless prosthesis in the control group under fluorescence microscopy. The metal-on-metal prosthesis of TKA is suitable to be fixed biologically for the rabbits, no matter whether use bone cement or not. The fixation strength of prosthesis by two layer stainless steel-mesh is better than that of the bone cement prosthesis at 12 months after operation.