Hip Department, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy.
Laboratory of Clinical Chemistry and Microbiology, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy.
Bone Joint J. 2019 Apr;101-B(4):372-377. doi: 10.1302/0301-620X.101B4.BJJ-2018-0752.R1.
Leucocyte esterase (LE) has been shown to be an accurate marker of prosthetic joint infection (PJI), and has been proposed as an alternative to frozen section (FS) histology for intraoperative diagnosis. In this study, the intraoperative assessment of LE was compared with FS histology for the diagnosis of prosthetic hip infection.
A total of 119 patients undergoing revision total hip arthroplasty (THA) between June 2015 and December 2017 were included in the study. There were 56 men and 63 women with a mean age of 66.2 years (27 to 88). Synovial fluid was collected before arthrotomy for the assessment of LE using enzymatic colourimetric strips. Between five and six samples were stained with haematoxylin and eosin for FS histology, and considered suggestive of infection when at least five polymorphonuclear leucocytes were found in five high-power fields.
The sensitivity and specificity of the LE assay were 100% and 93.8%, respectively; the positive (PPV) and the negative (NPV) predictive values were 79.3% and 100%, respectively. The mean time between the collection of the sample and the result being known was 20.1 minutes (sd 4.4). The sensitivity and specificity of FS histology were 78.3% and 96.9%, respectively; the PPV and the NPV were 85.7% and 94.9%, respectively. The mean time between the collection of the sample and the result being known was 27.2 minutes (sd 6.9).
The sensitivity of LE assay was higher, with similar specificity and diagnostic accuracy, compared with FS histology. The faster turnaround time, its ease of use, and low costs make LE assay a valuable alternative to FS histology. We now use it routinely for the intraoperative diagnosis of PJI. Cite this article: Bone Joint J 2019;101-B:372-377.
白细胞酯酶（LE）已被证实是假体关节感染（PJI）的准确标志物，并已被提议作为术中诊断的冰冻切片（FS）组织学的替代方法。本研究比较了 LE 的术中评估与 FS 组织学对假体髋关节感染的诊断价值。
本研究纳入了 2015 年 6 月至 2017 年 12 月期间行翻修全髋关节置换术（THA）的 119 例患者，其中男 56 例，女 63 例，平均年龄 66.2 岁（27 岁至 88 岁）。在关节切开术之前收集滑液，使用酶比色条评估 LE。对 5 至 6 个样本进行苏木精和伊红染色，当在 5 个高倍视野中发现至少 5 个多形核白细胞时，认为其具有感染的提示意义。
LE 检测的敏感性和特异性分别为 100%和 93.8%；阳性（PPV）和阴性（NPV）预测值分别为 79.3%和 100%。样本采集和结果获知之间的平均时间为 20.1 分钟（标准差 4.4）。FS 组织学的敏感性和特异性分别为 78.3%和 96.9%；PPV 和 NPV 分别为 85.7%和 94.9%。样本采集和结果获知之间的平均时间为 27.2 分钟（标准差 6.9）。
LE 检测的敏感性高于 FS 组织学，且具有相似的特异性和诊断准确性。LE 检测的快速周转时间、易用性和低成本使其成为 FS 组织学的有价值的替代方法。我们现在常规将其用于 PJI 的术中诊断。
Bone Joint J 2019;101-B:372-377.
