Department of Orthopaedics and Trauma Surgery of Hospital Clínic of Barcelona, Barcelona 08036, Spain.
Clin Orthop Relat Res. 2010 Aug;468(8):2238-43. doi: 10.1007/s11999-010-1254-3. Epub 2010 Feb 17.
Identifying the etiologic microorganism is essential to guide antimicrobial therapy in prosthetic joint infection.
QUESTIONS/PURPOSE: We (1) compared the frequency of positive cultures with synovial fluid inoculated in blood culture flasks (SF) with those of periprosthetic tissues or swabs in traditional cultures from patients with acute and chronic prosthetic joint infections (PJI) and (2) determined the sensitivity, specificity, and predictive values of the three methods.
We retrospectively reviewed 87 patients with PJIs (54 knees, 33 hips) and 63 patients with aseptic loosening (34 knees, 29 hips). Two SF, periprosthetic tissue, and swab samples were taken for culture in all 150 patients except for 14 in whom only one SF fluid sample was obtained. Synovial fluid was inoculated in blood culture flasks and periprosthetic tissue and swab samples in standard media. Positive cultures were identified with standard biochemical procedures.
SF samples were positive in 78 of 87 infected cases (90%), periprosthetic tissue samples were positive in 71 (82%), and swab samples were positive in 59 (68%). SF, periprosthetic tissue, and swab samples were positive more frequently in acute than in chronic infections (96% versus 82% for SF, 87% versus 74% for periprosthetic tissue, and 87% versus 44% for swabs). The sensitivity, specificity, and positive and negative predictive values of SF were 91, 100, 100, and 93 for acute infections and 79, 100, 100, and 88 for chronic infections, respectively.
SF samples cultured in flasks had higher sensitivity, specificity, and positive and negative predictive values for diagnosis of PJI when compared with standard tissue and swab samples. The usefulness of all samples was less in chronic than in acute infections.
Level II, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.
确定病原体对于指导人工关节感染的抗菌治疗至关重要。
问题/目的：我们（1）比较了急性和慢性人工关节感染（PJI）患者关节滑液接种于血培养瓶（SF）的阳性培养率与传统的关节周围组织或拭子培养率，并（2）确定了这三种方法的灵敏度、特异性和预测值。
我们回顾性分析了 87 例 PJI（54 膝，33 髋）和 63 例无菌性松动（34 膝，29 髋）患者。除了 14 例患者仅获得了 1 份 SF 液样本外，150 例患者的 SF 均进行了两份，同时对关节周围组织和拭子进行了两份培养。SF 接种于血培养瓶，关节周围组织和拭子接种于标准培养基。阳性培养物通过标准生化程序进行鉴定。
87 例感染病例中，SF 样本阳性 78 例（90%），关节周围组织样本阳性 71 例（82%），拭子样本阳性 59 例（68%）。SF、关节周围组织和拭子样本在急性感染中阳性率更高，而非慢性感染（SF 为 96%对 82%，关节周围组织为 87%对 74%，拭子为 87%对 44%）。SF 对急性感染的灵敏度、特异性、阳性预测值和阴性预测值分别为 91%、100%、100%和 93%，对慢性感染分别为 79%、100%、100%和 88%。
与标准组织和拭子样本相比，SF 样本在培养瓶中培养时，对 PJI 的诊断具有更高的灵敏度、特异性和阳性预测值和阴性预测值。在慢性感染中，所有样本的有用性均低于急性感染。
2 级，诊断研究。有关证据水平的完整描述，请参见作者指南。
