Schmalzried T P, Jasty M, Rosenberg A, Harris W H
Orthopaedic Biomechanics Laboratory and Hip Implant Unit, Department of Orthopaedic Surgery, Massachusetts General Hospital and Harvard Medical School, Boston.
J Appl Biomater. 1994;5(3):185-90. doi: 10.1002/jab.770050302.
Differences in bearing surface conformity and wear mechanisms suggest that the polyethylene (PE) wear debris generated by total knee replacement (TKR) prostheses should be different than that in total hip replacement prostheses (THR). To address this issue, PE wear debris and the cellular response in periprosthetic tissues from 19 failed TKRs was compared to that from 24 failed THRs using polarized light microscopy and a semiquantitative grading system. The foreign-body inflammatory reaction in the THR case was characterized by plump macrophages with a diffuse cytoplasmic birefringence when examined under polarized light, indicating the presence of multiple submicron particles of PE. The majority of PE particles were less than 1 mum in size and only a small fraction of the total were greater than 10 mum. The foreign-body inflammatory reaction in the TKR cases was characterized by giant cells with fewer macrophages. In the TKR specimens, the size range of PE particles was broader than in the hips. PE particles between 2 and 20 mum were frequent in TKR specimens; particles less than 1 mum in length were less common than in the THR specimens. Diffuse cytoplasmic birefringence was not a characteristic of the TKR cases. These histologic differences were so consistently distinct that the source of the specimen (i.e., from a THR or TKR) could be blindly determined by light microscopy.(ABSTRACT TRUNCATED AT 250 WORDS)
关节面贴合度及磨损机制的差异表明，全膝关节置换（TKR）假体产生的聚乙烯（PE）磨损碎屑应与全髋关节置换（THR）假体产生的不同。为解决这一问题，采用偏光显微镜和半定量分级系统，对19例失败的TKR假体周围组织中的PE磨损碎屑及细胞反应与24例失败的THR假体周围组织中的情况进行了比较。在偏光显微镜下观察时，THR病例中的异物炎症反应表现为饱满的巨噬细胞，胞质呈弥漫性双折射，表明存在多个亚微米级的PE颗粒。大多数PE颗粒尺寸小于1μm，仅一小部分大于10μm。TKR病例中的异物炎症反应以巨细胞为主，巨噬细胞较少。在TKR标本中，PE颗粒的尺寸范围比髋关节标本中的更宽。2至20μm的PE颗粒在TKR标本中很常见；长度小于1μm的颗粒比THR标本中少见。弥漫性胞质双折射不是TKR病例的特征。这些组织学差异非常明显，以至于通过光学显微镜可以盲目确定标本的来源（即来自THR还是TKR）。（摘要截断于250字）
