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【medical-news】关节液抽吸细胞计数和分类在诊断
Elie Ghanem, MD1, Javad Parvizi, MD, FRCS1, R. Stephen J. Burnett, MD, FRCS2, Peter F. Sharkey, MD1, Nahid Keshavarzi, MSc1, Ajay Aggarwal, MD2 and Robert L. Barrack, MD2
Background: Although there is no absolute diagnostic test for periprosthetic infection, the synovial fluid leukocyte count and neutrophil percentage have been reported to have high sensitivity and specificity. However, the cutoff values for these tests are not agreed upon. We sought to identify definite cutoff values for both the fluid leukocyte count and the neutrophil percentage that may help to diagnose infection at the site of a prosthetic joint.
Methods: We analyzed synovial fluid that had been aspirated preoperatively from 429 knees that had undergone revision arthroplasty at three different academic institutions; 161 knees were found to be infected, and 268 knees were not. Using receiver operating characteristic curves, we determined cutoff values for the fluid leukocyte count and neutrophil differential with an optimal balance of sensitivity and specificity for the diagnosis of periprosthetic infection. The sensitivity, specificity, and predictive values were calculated for those cutoff values. The erythrocyte sedimentation rate and C-reactive protein level cutoff values of 30 mm/hr and 10 mg/L, respectively, were combined with the cutoff values for the fluid leukocyte count and neutrophil percentage.
Results: The cutoff values for optimal accuracy in the diagnosis of infection were >1100 cells/10–3cm3 for the fluid leukocyte count and >64% for the neutrophil differential. When both tests yielded results below their cutoff values, the negative predictive value of the combination increased to 98.2% (95% confidence interval, 95.5% to 99.5%), whereas when both tests yielded results greater than their cutoff values, infection was confirmed in 98.6% (95% confidence interval, 94.9% to 99.8%) of the cases in our cohort. Similarly, when both the neutrophil percentage and the C-reactive protein level were less than the cutoff values of 64% and 10 mg/L, respectively, the presence of periprosthetic infection was very unlikely.
Conclusions: The synovial fluid leukocyte count and differential are useful adjuncts to the erythrocyte sedimentation rate and the C-reactive protein level in the preoperative workup of infection at the site of a total knee arthroplasty. The present study identified cutoff values for the leukocyte count (>1100 cells/10–3cm3) and neutrophil percentage (>64%) that can be used to diagnose infection. Combining the peripheral blood tests with the synovial fluid cell count and differential can improve their diagnostic value.
Level of Evidence: Diagnostic Level III. See Instructions to Authors for a complete description of levels of evidence.
本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领。 Cell Count and Differential of Aspirated Fluid in the Diagnosis of Infection at the Site of Total Knee Arthroplasty
关节液抽吸细胞计数和分类在诊断全膝关节置换感染中的作用
Elie Ghanem, MD1, Javad Parvizi, MD, FRCS1, R. Stephen J. Burnett, MD, FRCS2, Peter F. Sharkey, MD1, Nahid Keshavarzi, MSc1, Ajay Aggarwal, MD2 and Robert L. Barrack, MD2
Background: Although there is no absolute diagnostic test for periprosthetic infection, the synovial fluid leukocyte count and neutrophil percentage have been reported to have high sensitivity and specificity. However, the cutoff values for these tests are not agreed upon. We sought to identify definite cutoff values for both the fluid leukocyte count and the neutrophil percentage that may help to diagnose infection at the site of a prosthetic joint.
背景：尽管假体周围感染没有明确的诊断方法，但是有报告认为滑膜积液的白细胞计数和中性粒细胞比值有很高的敏感性和特异性。但是这些试验的临界值没有统一的标准。我们试图研究给出滑液白细胞计数和中性粒细胞比值的临界值来帮助诊断关节部位的假体周围感染。
Methods: We analyzed synovial fluid that had been aspirated preoperatively from 429 knees that had undergone revision arthroplasty at three different academic institutions; 161 knees were found to be infected, and 268 knees were not. Using receiver operating characteristic curves, we determined cutoff values for the fluid leukocyte count and neutrophil differential with an optimal balance of sensitivity and specificity for the diagnosis of periprosthetic infection. The sensitivity, specificity, and predictive values were calculated for those cutoff values. The erythrocyte sedimentation rate and C-reactive protein level cutoff values of 30 mm/hr and 10 mg/L, respectively, were combined with the cutoff values for the fluid leukocyte count and neutrophil percentage.
方法：我们对三个医学中心接受膝关节翻修手术的患者共429膝术前抽吸滑膜积液进行分析；161例膝关节发现感染，268例膝无感染。我们使用ROC曲线（受试者特征操作特征曲线）确定滑液中白细胞计数和中性粒细胞比值的临界值，使之能够在诊断假体周围感染时很好的平衡敏感性和特异性。对这些临界值计算其敏感性、特异性和预测价值。血沉和C反应蛋白的临界值分别为30 mm/hr 和10 mg/L，将其和滑液白细胞计数和中性粒比值结合进行临界值评估。
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作者:admin@医学,生命科学 2010-10-01 17:11
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