Acta Orthop Belg. 2021 Sep;87(3):553-556.
Septic arthritis is a serious condition that can lead to rapid destruction of joint if it is not rapidly diagnosed and treated appropriately. The reported annual incidence is 10 in 100 000 although this increases to 70 in 100 000 in those with risk factors for developing septic arthritis mainly rheumatoid arthritis and immune-compromised patients. The aim of this study is to examine the sensitivity and specificity, and thus the clinical usefulness, of gram stain results. This was a single centre, retrospective case series. All joint aspirates over a three year period from May 2015 to April 2018 were reviewed. The gram stain and final culture results noted. 830 samples were included from both native and replaced joints. Native joints accounted for a total of 701 cases (84%) of the aspirates, whilst those obtained from prosthetic joints 129 (16%). In 74 (9%) cases there was a discrepancy between the gram stain and culture results. The sensitivity of the gram stain in this case series is 22% and the specificity of the test is 99.6%. The clinician should have a low threshold for overlooking a negative gram stain result and place greater emphases on the clinical findings in conjunction with biochemical markers.
化脓性关节炎如果不能迅速诊断和适当治疗，可能会迅速导致关节破坏。据报道，其年发病率为每 10 万人中有 10 例，然而在有发生化脓性关节炎风险因素（主要为类风湿关节炎和免疫功能低下患者）的人群中，发病率上升至每 10 万人中有 70 例。本研究旨在评估革兰氏染色结果的灵敏度、特异性和临床实用性。这是一项单中心、回顾性病例系列研究。回顾了 2015 年 5 月至 2018 年 4 月三年内所有关节抽吸物的革兰氏染色和最终培养结果。共纳入了 830 例来自原发性和置换关节的样本。原发性关节占所有抽吸物的 701 例（84%），而来自人工关节的 129 例（16%）。在 74 例（9%）中，革兰氏染色和培养结果存在差异。在本病例系列中，革兰氏染色的灵敏度为 22%，特异性为 99.6%。临床医生不应忽视革兰氏染色的阴性结果，而应更加重视临床发现并结合生化标志物。
