Sigmund Irene K, McNally Martin A, Luger Markus, Böhler Christoph, Windhager Reinhard, Sulzbacher Irene
Department of Orthopaedics and Trauma Surgery, Medical University of Vienna, Vienna, Austria.
Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
Bone Joint Res. 2021 Aug;10(8):536-547. doi: 10.1302/2046-3758.108.BJR-2021-0058.R1.
Histology is an established tool in diagnosing periprosthetic joint infections (PJIs). Different thresholds, using various infection definitions and histopathological criteria, have been described. This study determined the performance of different thresholds of polymorphonuclear neutrophils (≥ 5 PMN/HPF, ≥ 10 PMN/HPF, ≥ 23 PMN/10 HPF) , when using the European Bone and Joint Infection Society (EBJIS), Infectious Diseases Society of America (IDSA), and the International Consensus Meeting (ICM) 2018 criteria for PJI.
A total of 119 patients undergoing revision total hip (rTHA) or knee arthroplasty (rTKA) were included. Permanent histology sections of periprosthetic tissue were evaluated under high power (400× magnification) and neutrophils were counted per HPF. The mean neutrophil count in ten HPFs was calculated (PMN/HPF). Based on receiver operating characteristic (ROC) curve analysis and the z-test, thresholds were compared.
Using the EBJIS criteria, a cut-off of ≥ five PMN/HPF showed a sensitivity of 93% (95% confidence interval (CI) 81 to 98) and specificity of 84% (95% CI 74 to 91). The optimal threshold when applying the IDSA and ICM criteria was ≥ ten PMN/HPF with sensitivities of 94% (95% CI 79 to 99) and 90% (95% CI 76 to 97), and specificities of 86% (95% CI 77 to 92) and 92% (95% CI 84 to 97), respectively. In rTKA, a better performance of histopathological analysis was observed in comparison with rTHA when using the IDSA criteria (p < 0.001).
With high accuracy, histopathological analysis can be supported as a confirmatory criterion in diagnosing periprosthetic joint infections. A threshold of ≥ five PMN/HPF can be recommended to distinguish between septic and aseptic loosening, with an increased possibility of detecting more infections caused by low-virulence organisms. However, neutrophil counts between one and five should be considered suggestive of infection and interpreted carefully in conjunction with other diagnostic test methods. Cite this article: 2021;10(8):536-547.
组织学是诊断人工关节周围感染（PJI）的既定工具。已经描述了使用各种感染定义和组织病理学标准的不同阈值。本研究确定了在使用欧洲骨与关节感染学会（EBJIS）、美国传染病学会（IDSA）和2018年国际共识会议（ICM）的PJI标准时，不同多形核中性粒细胞阈值（≥5个PMN/HPF、≥10个PMN/HPF、≥23个PMN/10个HPF）的性能。
共纳入119例行翻修全髋关节置换术（rTHA）或膝关节置换术（rTKA）的患者。对人工关节周围组织的永久组织学切片进行高倍镜（400倍放大）评估，并计算每个HPF中的中性粒细胞数量。计算十个HPF中的中性粒细胞平均计数（PMN/HPF）。基于受试者工作特征（ROC）曲线分析和z检验，对阈值进行比较。
使用EBJIS标准时，≥5个PMN/HPF的临界值显示敏感性为93%（95%置信区间（CI）81至98），特异性为84%（95%CI 74至91）。应用IDSA和ICM标准时的最佳阈值为≥10个PMN/HPF，敏感性分别为94%（95%CI 79至99）和90%（95%CI 76至97），特异性分别为86%（95%CI 77至92）和92%（95%CI 84至97）。在rTKA中，使用IDSA标准时，与rTHA相比，组织病理学分析表现更佳（p<0.001）。
组织病理学分析可作为诊断人工关节周围感染的确认标准，具有较高的准确性。建议采用≥5个PMN/HPF的阈值来区分感染性和无菌性松动，从而更有可能检测到更多由低毒力微生物引起的感染。然而，1至5之间的中性粒细胞计数应被视为感染的提示，并结合其他诊断测试方法进行仔细解读。引用本文：2021；10（8）：536-547。
