Haertlé Marco, Kolbeck Louisa, Macke Christian, Graulich Tilman, Stauß Ricarda, Omar Mohamed
Department of Trauma Surgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
J Clin Med. 2022 May 25;11(11):2979. doi: 10.3390/jcm11112979.
The diagnosis of periprosthetic infections (PJI) can be challenging in clinical practice because the clinical presentations of aseptic loosening and low-grade infections are similar. Semiquantitative evaluation of leukocyte esterase (LE) in synovial fluid using a urine strip test has already established itself as a diagnostic method over the past decade. The analysis of LE in synovial fluid leads to a high number of false-positive test results. In the present study, the value of a combined semiquantitative determination of glucose and LE in synovial fluid to improve the diagnosis of PJI was investigated. Over a 4-year period, 145 synovial samples were collected from patients who developed joint effusion after arthroplasty. LE and glucose test strips were considered as an index test for the diagnosis of PJI. A ++ or +++ LE and a negative glucose test strip reading were considered as positive test results. Modified diagnostic criteria for PJI as recommended by the Musculoskeletal Infection Society (MSIS) served as the reference test, except that intraoperative findings were excluded. Forty-six out of 145 samples were classified as septic complication according to the reference test. In regard to PJI, our data showed that combined use of LE and glucose strip test reading displayed a 98.0% specificity (95% confidence interval (CI): 95.2% to 100%), a 50% sensitivity (95% CI: 35.6% to 64.4%), a 92% positive predictive value (95% CI: 81.4% to 100.0%), and an 80.3% negative predictive value (95% CI: 73.2% to 87.4%). In contrast, the exclusive analysis of LE on the urine strip to diagnose PJI demonstrated a 90.9% specificity (95% CI: 85.2% to 96.6%), a 67.4% sensitivity (95% CI: 53.8% to 80.9%), a 77.5% positive predictive value (95% CI: 64.6% to 90.4%), and an 85.7% negative predictive value (5% CI: 79.0% to 92.4%). A combination of LE and glucose test pad reading is considered superior as a potential "rule-in" method for the diagnosis of PJI compared with LE test pad analysis alone. However, combined LE and glucose synovial fluid testing also demonstrated lower test sensitivity and thus diagnostic accuracy compared with LE analysis alone. Therefore, combined glucose and LE test pad analysis does not represent a sufficient diagnostic standard to exclude PJI with certainty.
在临床实践中，假体周围感染（PJI）的诊断具有挑战性，因为无菌性松动和低度感染的临床表现相似。在过去十年中，使用尿试纸条对滑液中的白细胞酯酶（LE）进行半定量评估已成为一种诊断方法。滑液中LE的分析会导致大量假阳性检测结果。在本研究中，探讨了联合半定量测定滑液中葡萄糖和LE以改善PJI诊断的价值。在4年期间，从关节置换术后出现关节积液的患者中收集了145份滑液样本。LE和葡萄糖试纸条被视为诊断PJI的指标检测。LE为++或+++且葡萄糖试纸条读数为阴性被视为阳性检测结果。除排除术中发现外，采用肌肉骨骼感染学会（MSIS）推荐的PJI改良诊断标准作为参考检测。根据参考检测，145份样本中有46份被归类为感染性并发症。关于PJI，我们的数据显示，联合使用LE和葡萄糖试纸条读数显示特异性为98.0%（95%置信区间（CI）：95.2%至100%），敏感性为50%（95%CI：35.6%至64.4%），阳性预测值为92%（95%CI：81.4%至100.0%），阴性预测值为80.3%（95%CI：73.2%至87.4%）。相比之下，仅通过尿试纸条对LE进行分析来诊断PJI的特异性为90.9%（95%CI：85.
