Department of Orthopedics and Trauma Surgery, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
Int Orthop. 2021 Apr;45(4):837-846. doi: 10.1007/s00264-020-04889-z. Epub 2020 Nov 27.
Besides other diagnostic test methods, established serum inflammatory markers such as serum C-reactive protein or leukocyte count are widely used preoperatively to aid in diagnosing periprosthetic joint infections (PJI). Although low accuracies were reported, these parameters are easily accessible and routinely available. Novel biomarkers with promising results in diagnosing PJI (platelet count to mean platelet volume ratio) or other infectious conditions (percentage of neutrophils, neutrophils to lymphocytes ratio) were described. The purpose of this study was to investigate the diagnostic value of established and novel serum inflammatory biomarkers for the diagnosis of PJI so as to compare the results to find the serum inflammatory marker with the best performance.
In 177 patients with a previous total hip (n = 91) or knee (n = 86) arthroplasty and indicated revision surgery, the diagnostic value of the routinely available serum inflammatory markers C-reactive protein (CRP), white blood cell count (WBC), percentage of neutrophils (%N), neutrophils to lymphocytes ratio (NLR), fibrinogen and platelet count to mean platelet volume ratio (PC/mPV) were examined retrospectively via receiver operating characteristic curve analysis (AUC). The curves were compared using the z-test.
Sensitivities of serum CRP, WBC, %N, NLR, fibrinogen and PC/mPV were calculated with 68%, 36%, 66%, 63%, 69% and 43%, respectively. Specificities were 87%, 89%, 67%, 73%, 89% and 81%, respectively. Serum CRP (0.78) and fibrinogen (0.79) showed significantly better AUCs compared with serum WBC (0.63), %N (0.67), NLR (0.68) and PC/mPV (0.62) (p < 0.0001). Patients with PJI caused by a low-virulent microorganism (median CRP: 17.6 mg/L) obtained lower CRP levels compared with infections caused by high-virulent microorganisms (median CRP: 49.2 mg/L; p = 0.044). The combination of CRP and fibrinogen showed a better sensitivity (77%) with similar specificity (83%) than one method alone but not at a significant level (CRP (p = 0.200); fibrinogen (p = 0.437)).
Serum CRP and fibrinogen showed the best accuracies among these widely available serum inflammatory parameters. However, due to the insufficient performance, these biomarkers can only be recommended as suggestive criteria in diagnosing PJI. The preoperative workup should always be complemented by more specific tests such as synovial fluid analysis.
除其他诊断测试方法外，已建立的血清炎症标志物（如血清 C 反应蛋白或白细胞计数）也广泛用于术前辅助诊断假体周围关节感染（PJI）。尽管报道的准确性较低，但这些参数易于获得且常规可用。已经描述了一些具有诊断 PJI （血小板计数与平均血小板体积比）或其他感染性疾病（中性粒细胞百分比、中性粒细胞与淋巴细胞比）有前景的新型生物标志物。本研究旨在探讨已建立和新型血清炎症标志物在诊断 PJI 中的诊断价值，以便比较结果，找到表现最佳的血清炎症标志物。
在 177 名先前接受过全髋关节（n=91）或全膝关节（n=86）置换术并需要进行翻修手术的患者中，通过接收者操作特征曲线分析（AUC）回顾性地检查了常规可用的血清炎症标志物 C 反应蛋白（CRP）、白细胞计数（WBC）、中性粒细胞百分比（%N）、中性粒细胞与淋巴细胞比（NLR）、纤维蛋白原和血小板计数与平均血小板体积比（PC/mPV）的诊断价值。使用 z 检验比较曲线。
血清 CRP、WBC、%N、NLR、纤维蛋白原和 PC/mPV 的敏感性分别为 68%、36%、66%、63%、69%和 43%，特异性分别为 87%、89%、67%、73%、89%和 81%。血清 CRP（0.78）和纤维蛋白原（0.79）的 AUC 明显优于血清 WBC（0.63）、%N（0.67）、NLR（0.68）和 PC/mPV（0.62）（p<0.0001）。由低毒微生物引起的 PJI 患者（中位 CRP：17.6mg/L）的 CRP 水平低于由高毒微生物引起的感染患者（中位 CRP：49.2mg/L；p=0.044）。CRP 和纤维蛋白原的组合具有更好的敏感性（77%）和相似的特异性（83%），但并不显著（CRP（p=0.200）；纤维蛋白原（p=0.437））。
在这些广泛可用的血清炎症参数中，血清 CRP 和纤维蛋白原的准确性最高。然而，由于性能不足，这些生物标志物只能作为诊断 PJI 的提示性标准。术前检查应始终辅以更具体的测试，如关节液分析。
