Exeter Knee Reconstruction Unit, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter NHS Foundation Trust, Exeter, United Kingdom.
University of Exeter Medical School, College of Medicine and Health, St Luke's Campus, Exeter, United Kingdom.
J Arthroplasty. 2019 Dec;34(12):3035-3039. doi: 10.1016/j.arth.2019.07.035. Epub 2019 Jul 30.
The diagnosis of prosthetic joint infection (PJI) is challenging because no single test has consistently demonstrated an adequate discriminative potential. The combination of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) with adequate thresholds is well established. This study sought to investigate the role of plasma viscosity (PV) in the diagnosis of PJI following painful total knee arthroplasty.
The medical notes, and hematological and microbiology results of 310 patients who underwent revision for a painful total knee arthroplasty were evaluated. Infection was confirmed using Musculoskeletal Infection Society criteria in 102 patients (32.9%), whereas 208 patients (67.1%) were classified as noninfected. Serum investigations including ESR, CRP, and PV were analyzed using receiver observer curves and optimal cutoff points identified.
There was a strong correlation between PV and both ESR and CRP. The area under curve was 0.814 for PV and 0.812 for ESR. Statistical analysis showed noninferiority of PV as compared to ESR in diagnosing PJI. A PV value of ≥ 1.81 mPa.s. had the best efficiency of 82.1%. Combining a CRP ≥ 13.5 mg/L with a PV ≥ 1.81 mPa.s. in a serial test approach yielded the highest specificity of 97.9% and positive likelihood ratio of 22.8. Sensitivity was 47.9% and a negative likelihood ratio of 0.53.
PV is noninferior to ESR in diagnosing PJI. Its use is justified in clinical practice. It is cheaper, quicker, more efficient, and not influenced by hematocrit levels or medication. In this cohort, a PV value ≥ 1.81 mPa.s. would be an adequate cutoff to diagnose PJI in combination with CRP ≥ 13.5 mg/L.
假体关节感染（PJI）的诊断具有挑战性，因为没有单一的测试能够始终表现出足够的鉴别潜力。红细胞沉降率（ESR）和 C 反应蛋白（CRP）与适当的阈值相结合已得到充分确立。本研究旨在探讨血浆粘度（PV）在诊断全膝关节置换术后疼痛性 PJI 中的作用。
评估了 310 例因全膝关节置换术后疼痛而接受翻修手术患者的病历、血液学和微生物学结果。根据肌肉骨骼感染学会标准，102 例患者（32.9%）确诊为感染，208 例患者（67.1%）为非感染。通过接收者操作者曲线和确定最佳截断点分析了包括 ESR、CRP 和 PV 在内的血清研究。
PV 与 ESR 和 CRP 之间存在很强的相关性。PV 的曲线下面积为 0.814，ESR 为 0.812。统计分析表明，PV 在诊断 PJI 方面不劣于 ESR。PV 值≥1.81 mPa.s. 的效率最佳，为 82.1%。在连续测试方法中，将 CRP≥13.5mg/L 与 PV≥1.81 mPa.s. 结合使用，可获得最高的特异性 97.9%和阳性似然比 22.8。敏感性为 47.9%，阴性似然比为 0.53。
PV 在诊断 PJI 方面不劣于 ESR。在临床实践中使用是合理的。它更便宜、更快、更有效，不受红细胞压积水平或药物的影响。在本队列中，PV 值≥1.81 mPa.s.与 CRP≥13.5mg/L 结合使用将是诊断 PJI 的适当截断值。
