Klinik und Poliklinik für Orthopädie und Sportorthopädie, Klinikum rechts der Isar der Technischen Universität München, Ismaninger Str. 22, 81675, Munich, Germany.
Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Technische Universität München, Trogerstr. 30, 81675, Munich, Germany.
Int Orthop. 2020 Sep;44(9):1629-1637. doi: 10.1007/s00264-020-04552-7. Epub 2020 Apr 15.
A major obstacle for the treatment of prosthetic joint infection (PJI) is the identification of the underlying causative organism. While the diagnostic criteria ruling PJI in or out have become ever more accurate, the detection of the causative pathogen(s) still relies mostly on conventional and time-consuming microbial culture. The aim of this study was to evaluate the diagnostic potential of a second-generation multiplex PCR assay (Unyvero ITI G2, Curetis AG, Holzgerlingen, Germany) used on synovial fluid specimens. Our hypothesis was that the method would yield a higher diagnostic accuracy in the pre-operative workup than synovial fluid culture. Thus, a more precise classification of septic and aseptic prosthesis failure could be achieved before revision surgery.
Prospectively collected frozen joint fluid specimens from 26 patients undergoing arthroplasty revision surgery of the hip or knee were tested as per the manufacturer's protocol. Sensitivities, specificities, positive and negative predictive values as well as positive and negative likelihood ratios with corresponding confidence intervals were estimated using the statistical software R. A combination of the serum C-reactive protein (CRP) level, leukocyte count, erythrocyte sedimentation rate, joint fluid culture, tissue biopsy culture, and tissue biopsy histology served as the gold standard.
Of the 26 patients included in the study, 15 were infected and 11 were aseptic. Conventional joint fluid culture showed a sensitivity of 0.67 and a specificity of 0.91. Joint fluid multiplex PCR yielded a sensitivity of 0.8 and a specificity of 1.0.
Using the second-generation Unyvero ITI cartridge on joint fluid aspirate for the detection of prosthetic joint infection, we were able to achieve a higher diagnostic accuracy than with conventional culture. We conclude that to improve pathogen detection before revision surgery, this method represents a valuable and practicable tool.
治疗人工关节感染（PJI）的主要障碍是确定潜在的病原体。虽然诊断 PJI 的标准变得越来越准确，但病原体的检测仍然主要依赖于传统的、耗时的微生物培养。本研究旨在评估第二代多重 PCR 检测方法（Unyvero ITI G2，Curetis AG，德国霍尔茨基尔根）在关节滑液标本中的诊断潜力。我们的假设是，与关节滑液培养相比，该方法在术前检查中具有更高的诊断准确性。因此，在进行翻修手术之前，可以更精确地对感染性和无菌性假体失败进行分类。
前瞻性收集 26 例髋关节或膝关节人工关节翻修术患者的冷冻关节滑液标本，按照制造商的方案进行检测。使用 R 统计软件估算敏感性、特异性、阳性和阴性预测值以及阳性和阴性似然比及其置信区间。血清 C 反应蛋白（CRP）水平、白细胞计数、红细胞沉降率、关节滑液培养、组织活检培养和组织活检组织学的组合作为金标准。
在纳入研究的 26 例患者中，15 例为感染，11 例为无菌。传统关节滑液培养的敏感性为 0.67，特异性为 0.91。关节液多重 PCR 的敏感性为 0.8，特异性为 1.0。
使用第二代 Unyvero ITI 试剂盒对关节滑液抽吸物进行检测，可提高诊断准确性。我们认为，为了提高翻修手术前的病原体检测水平，该方法是一种有价值且实用的工具。
