Niedzwiecki S, Klapperich C, Short J, Jani S, Ries M, Pruitt L
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
J Biomed Mater Res. 2001 Aug;56(2):245-9. doi: 10.1002/1097-4636(200108)56:2<245::aid-jbm1091>3.0.co;2-t.
Quantification of ultrahigh molecular weight polyethylene (UHMWPE) wear debris remains a challenging task in orthopedic device analysis. Currently, the weight loss method is the only accepted practice for quantifying the amount of wear generated from a PE component. This technique utilizes loaded soak controls and weight differences to account for polymeric material lost through wear mechanisms. This method enables the determination of the amount of wear in the orthopedic device, but it provides no information about debris particulate size distribution. In order to shed light on wear mechanisms, information about the wear debris and its size distribution is necessary. To date, particulate isolation has been performed using the base digestion technique. The method uses a strong base, ultracentrifugation, and filtration to digest serum constituents and to isolate PE debris from sera. It should be noted that particulate isolation methods provide valuable information about particulate size distribution and may elucidate the mechanisms of wear associated with polymeric orthopedic implants; however, these techniques do not yet provide a direct measure of the amount of wear. The aim of this study is to present alternative approaches to wear particle isolation for analysis of polymer wear in total joint replacements without recourse to ultracentrifugation. Three polymer wear debris isolation techniques (the base method, an acid treatment, and an enzymatic digestion technique) are compared for effectiveness in simulator studies. A requirement of each technique is that the wear particulate must be completely devoid of serum proteins in order to effectively image and count these particles. In all methods the isolation is performed through filtration and chemical treatment. Subsequently, the isolated polymer particles are imaged using scanning electron microscopy and quantified with digital image analysis. The results from this study clearly show that isolation can be performed without the use of ultracentrifugation and that these methods provide a viable option for wear debris analysis.
在骨科器械分析中，超高分子量聚乙烯（UHMWPE）磨损颗粒的定量分析仍然是一项具有挑战性的任务。目前，失重法是唯一被认可的用于量化PE部件磨损量的方法。该技术利用加载浸泡对照和重量差异来计算因磨损机制而损失的聚合材料量。这种方法能够确定骨科器械中的磨损量，但它无法提供关于磨损颗粒尺寸分布的任何信息。为了深入了解磨损机制，有关磨损颗粒及其尺寸分布的信息是必要的。迄今为止，颗粒分离一直采用碱消化技术。该方法使用强碱、超速离心和过滤来消化血清成分，并从血清中分离出PE颗粒。需要注意的是，颗粒分离方法提供了有关颗粒尺寸分布的有价值信息，并可能阐明与聚合物骨科植入物相关的磨损机制；然而，这些技术尚未提供磨损量的直接测量方法。本研究的目的是提出替代的磨损颗粒分离方法，用于在不借助超速离心的情况下分析全关节置换术中的聚合物磨损。在模拟器研究中，比较了三种聚合物磨损颗粒分离技术（碱法、酸处理和酶消化技术）的有效性。每种技术的一个要求是，磨损颗粒必须完全不含血清蛋白，以便有效地对这些颗粒进行成像和计数。在所有方法中，分离都是通过过滤和化学处理进行的。随后，使用扫描电子显微镜对分离出的聚合物颗粒进行成像，并通过数字图像分析进行定量。本研究的结果清楚地表明，无需使用超速离心即可进行分离，并且这些方法为磨损颗粒分析提供了一个可行的选择。
