Rothman Orthopaedic Institute at Thomas Jefferson University, Philadelphia, Pennsylvania.
J Arthroplasty. 2022 Dec;37(12):2437-2443.e1. doi: 10.1016/j.arth.2022.06.016. Epub 2022 Jun 22.
The diagnostic utility of synovial C-reactive protein (CRP) has been debated for a while. Existing studies are limited by small sample sizes and using outdated criteria for periprosthetic joint infection (PJI). Furthermore, the relationship between synovial and serum CRP has rarely been investigated in the setting of PJI. This study aimed to evaluate the diagnostic utility of synovial CRP and to assess its relationship with serum CRP and other common biomarkers.
We reviewed 621 patients who underwent evaluation for PJI prior to revision arthroplasty from 2014 to 2021. Biomarkers, including serum CRP and erythrocyte sedimentation rate, synovial CRP, polymorphonuclear leukocyte percentage, white blood cell count, and alpha-defensin, were evaluated using the 2018 International Consensus Meeting criteria.
In total, 194 patients had a PJI; 394 were considered aseptic failures and 33 were inconclusive. Synovial CRP showed an area under the curve (AUC) of 0.951 (95% CI, 0.932-0.970) with 74.2% sensitivity and 98.0% specificity, whereas, serum CRP had an AUC of 0.926 (95% CI, 0.903-0.949) with 83.5% sensitivity and 88.3% specificity. There was a good correlation between synovial and serum CRP (R = 0.703; 95% CI, 0.604-0.785). The combination of serum and synovial CRP yielded a significantly higher AUC than that obtained when using serum CRP alone (AUC 0.964 versus 0.926, P = .016).
Synovial CRP demonstrated excellent accuracy when used to determine the presence of PJI. There was a good correlation between serum and synovial CRP levels in revision arthroplasty patients and the combined use of serum and synovial CRP proved to be more accurate than the serum test alone. These findings support the use of synovial CRP as an adjunct in the workup of PJI.
滑膜 C 反应蛋白（CRP）的诊断效用一直存在争议。现有的研究受到样本量小和使用过时的假体周围关节感染（PJI）标准的限制。此外，在 PJI 情况下，滑膜和血清 CRP 之间的关系很少被研究。本研究旨在评估滑膜 CRP 的诊断效用，并评估其与血清 CRP 和其他常见生物标志物的关系。
我们回顾了 2014 年至 2021 年间接受翻修关节成形术评估的 621 例 PJI 患者。使用 2018 年国际共识会议标准评估了包括血清 CRP 和红细胞沉降率、滑膜 CRP、多形核白细胞百分比、白细胞计数和α-防御素在内的生物标志物。
共有 194 例患者患有 PJI；394 例被认为是无菌性失败，33 例结果不确定。滑膜 CRP 的曲线下面积（AUC）为 0.951（95%置信区间，0.932-0.970），灵敏度为 74.2%，特异性为 98.0%，而血清 CRP 的 AUC 为 0.926（95%置信区间，0.903-0.949），灵敏度为 83.5%，特异性为 88.3%。滑膜和血清 CRP 之间存在良好的相关性（R=0.703；95%置信区间，0.604-0.785）。与单独使用血清 CRP 相比，血清和滑膜 CRP 的联合使用显著提高了 AUC（AUC 0.964 与 0.926，P=0.016）。
滑膜 CRP 在确定 PJI 时具有出色的准确性。在接受翻修关节成形术的患者中，血清和滑膜 CRP 水平之间存在良好的相关性，并且血清和滑膜 CRP 的联合使用比单独使用血清检测更准确。这些发现支持将滑膜 CRP 作为 PJI 检查的辅助手段。
