Cyndari Karen I, Goodheart Jacklyn R, Miller Mark A, Oest Megan E, Damron Timothy A, Mann Kenneth A
Department of Orthopaedic Surgery, State University of New York Upstate Medical University, Syracuse, New York.
J Arthroplasty. 2017 Jul;32(7):2289-2300. doi: 10.1016/j.arth.2017.01.047. Epub 2017 Feb 3.
Loss of mechanical interlock between cement and bone with in vivo service has been recently quantified for functioning, nonrevised, cemented total knee arthroplasties (TKAs). The cause of interlocking trabecular resorption is not known. The goal of this study is to quantify the distribution of PE debris at the cement-bone interface and determine if polyethylene (PE) debris is locally associated with loss of interlock.
Fresh, nonrevised, postmortem-retrieved TKAs (n = 8) were obtained en bloc. Laboratory-prepared constructs (n = 2) served as negative controls. The intact cement-bone interface of each proximal tibia was embedded in Spurr's resin, sectioned, and imaged under polarized light to identify birefringent PE particles. PE wear particle number density was quantified at the cement-bone interface and distal to the interface, and then compared with local loss of cement-bone interlock.
The average PE particle number density for postmortem-retrieved TKAs ranged from 8.6 (1.3) to 24.9 (3.1) particles/mm (standard error) but was weakly correlated with years in service. The average particle number density was twice as high as distal (>5mm) to the interface compared to at the interface. The local loss of interlock at the interface was not related to the presence, absence, or particle density of PE.
PE debris can migrate extensively along the cement-bone interface of well-fixed tibial components. However, the amount of local bone loss at the cement-bone interface was not correlated with the amount of PE debris at the interface, suggesting that the observed loss of trabecular interlock in these well-fixed TKAs may be due to alternative factors.
最近已对功能正常、未翻修的骨水泥型全膝关节置换术（TKA）在体内使用时骨水泥与骨之间机械嵌合的丧失情况进行了量化。小梁骨吸收性嵌合丧失的原因尚不清楚。本研究的目的是量化聚乙烯（PE）碎片在骨水泥-骨界面的分布，并确定PE碎片是否与嵌合丧失存在局部关联。
完整获取新鲜、未翻修、死后取出的TKA（n = 8）。实验室制备的结构（n = 2）用作阴性对照。将每个近端胫骨完整的骨水泥-骨界面嵌入Spurr树脂中，切片，并在偏光下成像以识别双折射PE颗粒。对骨水泥-骨界面及其远端的PE磨损颗粒数密度进行量化，然后与骨水泥-骨嵌合的局部丧失情况进行比较。
死后取出的TKA的平均PE颗粒数密度范围为8.6（1.3）至24.9（3.1）个颗粒/mm（标准误差），但与使用年限的相关性较弱。与界面处相比，界面远端（>5mm）的平均颗粒数密度高出两倍。界面处嵌合的局部丧失与PE的存在、缺失或颗粒密度无关。
PE碎片可沿固定良好的胫骨部件的骨水泥-骨界面广泛迁移。然而，骨水泥-骨界面处局部骨丢失的量与界面处PE碎片的量不相关，这表明在这些固定良好的TKA中观察到的小梁骨嵌合丧失可能是由其他因素导致的。
