Department of Orthopaedic Surgery, Mayo Clinic Arizona, Phoenix, AZ.
Department of Microbiology, Mayo Clinic Arizona, Phoenix, AZ.
J Arthroplasty. 2020 Aug;35(8):2217-2222. doi: 10.1016/j.arth.2020.03.011. Epub 2020 Mar 14.
The diagnosis of periprosthetic joint infection is often challenging in the setting of low aspiration volumes, or in the presence of infection with a slow-growing organism. We sought to determine if an optimal threshold of aspiration fluid volume exists when cultures from the preoperative aspiration are compared to intraoperative cultures.
All revision total hip and knee arthroplasty procedures over 5 years at our institution were reviewed. Cases were excluded if they underwent joint lavage during aspiration, had an antibiotic spacer in place, were suspected of adverse local tissue reaction to metal debris, did not have an accurate aspiration volume recorded, or if there were no aspiration or operative cultures available. Receiver operating characteristic curves were used to evaluate aspiration volume for identifying cases with identical aspiration and culture results.
A total of 857 revision cases were reviewed, among which 294 met inclusion criteria. There were 45 cases (15.3%) with discordant aspiration and operative cultures. The mean aspiration volume for identical cases was significantly higher than for discordant cases (19.1 vs 10.2 mL, P = .02). The proportion of slow-growing organisms was significantly greater among discordant compared to identical operative cultures (52.4% for discordant cases vs 8.2% for identical cases, P < .001). The optimal cutoff value for predicting identical cultures was 3.5 mL for typical organisms and 12.5 mL for slow-growing organisms.
Aspiration cultures are more likely to correlate with intraoperative cultures with higher aspiration volumes, and the optimal aspiration volume is higher for slow-growing organisms.
在抽吸量低或存在生长缓慢的感染病原体的情况下，假体周围关节感染的诊断常常具有挑战性。我们旨在确定当术前抽吸的培养物与术中培养物进行比较时，抽吸液量是否存在最佳阈值。
回顾我院 5 年内所有翻修全髋关节和膝关节置换术。如果在抽吸过程中进行了关节灌洗、放置了抗生素间隔器、怀疑对金属碎片有不良局部组织反应、未记录准确的抽吸量或没有抽吸或手术培养物，则排除病例。使用受试者工作特征曲线来评估抽吸量，以确定具有相同抽吸和培养结果的病例。
共回顾了 857 例翻修病例，其中 294 例符合纳入标准。有 45 例（15.3%）抽吸和培养结果不一致。相同病例的平均抽吸量明显高于不一致病例（19.1 比 10.2 毫升，P =.02）。与相同的手术培养物相比，不一致的抽吸培养物中生长缓慢的病原体比例明显更高（52.4% 对不一致病例，8.2% 对相同病例，P <.001）。预测相同培养物的最佳截断值为典型病原体时为 3.5 毫升，为生长缓慢的病原体时为 12.5 毫升。
抽吸培养物与术中培养物更相关，抽吸量越高，抽吸培养物与术中培养物更相关，生长缓慢的病原体的最佳抽吸量更高。
