Mihalič René, Zdovc Jurij, Brumat Peter, Trebše Rihard
Service for Bone Infections, Valdoltra Orthopaedic Hospital, Ankaran, Slovenia.
Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia.
Bone Jt Open. 2020 Dec 7;1(12):737-742. doi: 10.1302/2633-1462.112.BJO-2020-0166.R1.
Synovial fluid white blood cell (WBC) count and percentage of polymorphonuclear cells (%PMN) are elevated at periprosthetic joint infection (PJI). Leucocytes produce different interleukins (IL), including IL-6, so we hypothesized that synovial fluid IL-6 could be a more accurate predictor of PJI than synovial fluid WBC count and %PMN. The main aim of our study was to compare the predictive performance of all three diagnostic tests in the detection of PJI.
Patients undergoing total hip or knee revision surgery were included. In the perioperative assessment phase, synovial fluid WBC count, %PMN, and IL-6 concentration were measured. Patients were labeled as positive or negative according to the predefined cut-off values for IL-6 and WBC count with %PMN. Intraoperative samples for microbiological and histopathological analysis were obtained. PJI was defined as the presence of sinus tract, inflammation in histopathological samples, and growth of the same microorganism in a minimum of two or more samples out of at least four taken.
In total, 49 joints in 48 patients (mean age 68 years (SD 10; 26 females (54%), 25 knees (51%)) were included. Of these 11 joints (22%) were infected. The synovial fluid WBC count and %PMN predicted PJI with sensitivity, specificity, accuracy, PPV, and NPV of 82%, 97%, 94%, 90%, and 95%, respectively. Synovial fluid IL-6 predicted PJI with sensitivity, specificity, accuracy, PPV, and NPV of 73%, 95%, 90%, 80%, and 92%, respectively. A comparison of predictive performance indicated a strong agreement between tests.
Synovial fluid IL-6 is not superior to synovial fluid WBC count and %PMN in detecting PJI.Level of Evidence: Therapeutic Level IICite this article: 2020;1-12:737-742.
人工关节周围感染（PJI）时，滑液白细胞（WBC）计数及多形核细胞百分比（%PMN）会升高。白细胞会产生不同的白细胞介素（IL），包括IL-6，因此我们推测滑液IL-6可能比滑液WBC计数及%PMN更准确地预测PJI。本研究的主要目的是比较这三种诊断检测方法在检测PJI方面的预测性能。
纳入接受全髋关节或膝关节翻修手术的患者。在围手术期评估阶段，测量滑液WBC计数、%PMN及IL-6浓度。根据IL-6和WBC计数与%PMN的预定义临界值，将患者标记为阳性或阴性。获取术中样本进行微生物学和组织病理学分析。PJI定义为存在窦道、组织病理学样本中有炎症，以及在至少采集的4份样本中至少2份或更多份样本中培养出相同微生物。
共纳入48例患者的49个关节（平均年龄68岁（标准差10；26例女性（54%），25个膝关节（51%））。其中11个关节（22%）感染。滑液WBC计数及%PMN预测PJI的敏感性、特异性、准确性、阳性预测值（PPV）和阴性预测值（NPV）分别为82%、97%、94%、90%和95%。滑液IL-6预测PJI的敏感性、特异性、准确性、PPV和NPV分别为73%、95%、90%、80%和92%。预测性能比较表明各检测方法之间有很强的一致性。
在检测PJI方面，滑液IL-6并不优于滑液WBC计数及%PMN。证据级别：治疗性II级引用本文：2020；1 - 12：737 - 742。
