运用偏振光观测聚乙烯磨屑颗粒诱导人工关节假体无菌性松动

Using Polarized Light to Observe Polyethylene Wear Particles Induced Artificial Joint Aseptic Loosening

目的:探讨运用偏振光显微镜来观测无菌性松动人工关节假体周围的聚乙烯颗粒分布,评估其在研究磨屑颗粒诱导假体无菌性松动机制及防治措施等实验研究中的可行性。方法:我们用雌性新西兰大白兔建立动物模型,在左侧胫骨髓腔内植入羟基磷灰石(hydroxyapatite,HA)涂层假体。并分别于假体表面和膝关节腔内植入0.5×10^7超高分子量聚乙烯(Ultra-high molecular weight polyethylene,UHMWPE)颗粒。术后行四环素荧光双标记。膝关节滑膜组织苏木精-伊红(hematoxylin-eosin,HE)染色、骨组织改良丽春红染色后分别用普通光镜和偏振光镜观察,未染色的骨组织行荧光显微镜和偏振光镜观察。结果:在聚乙烯颗粒刺激下,膝关节滑膜组织增生明显,骨-假体结合差,假体周围骨小梁稀疏,偏振光显微镜可清晰显示双折光性的聚乙烯颗粒在膝关节分布于滑膜及其深层结缔组织中,在骨-假体间隙间大量充填,阻碍骨-假体整合。结论:运用偏振光显微镜可以清晰而简便地观察滑膜和假体周围的聚乙烯颗粒分布,与传统实验方法相比,更加直观、简便和经济。

Objective: Using polarization microscope to observe the distribution of polyethylene particles around aseptic loosened artificial joints in animal model could evaluate its feasibility in the studies of the mechanism and the preventative and therapeutic interventions of wear debirs induced implant aseptic loosening. Methods: We used female New Zealand white rabbits to establish animal model. HA-coated implants were inserted into the left tibia, and 0.5×10^7 UHMWPE wear particles were injected both around implants and into knee joints. Tetracycline double labeling was used postoperatively. The synovial membrane of knee joint was observed by HE staining, while bone was observed by modified Ponceau staining under light microscope and polarization microscope. Non-stained bone was observed under fluorescence and polarization microscope. Results: The polyethylene particles induced synovial membrane hyperplasia, poor bone-implant integration, sparse peri-implant bone trabecula. Birefringent particles were observed in the whole synovial membrane and between the bone-implant interface under polarized light, which hampered bone-implant integration. Conclusion: The distribution of polyethylene particles in the synovial membrane and around implant could be observed easily under polarized light. Compared to traditional methods, polarization microscopy is much more intuitive, convenient and economical.