摘要目的:探讨外固定支架钉-骨界面表面培养在钉道感染诊断中的应用价值。方法:前瞻性筛选2023年6月至9月期间在南方医科大学南方医院创伤骨科利用外固定支架治疗后拟行部分或全部外固定支架拆除的患者。对螺钉所在钉道的分泌物（钉-软组织界面）行涂板细菌培养；对螺钉位于骨内的螺纹（钉-骨界面）用胰酪大豆胨琼脂浇筑进行螺钉表面培养，比较两个界面的培养结果，并对培养阳性者行细菌定性培养及药物敏感试验。结果:共纳入23例患者，男18例，女5例；年龄（37.3±17.6）岁；外固定支架佩戴时间为8.1（4.0，11.3）个月。共培养212个标本，钉-软组织界面细菌培养阳性率为53.8%（57/106），显著高于钉-骨界面[17.9%（19/106）]，差异有统计学意义（ P< 0.05）。钉-骨界面与钉-软组织界面细菌培养结果并未显示相关性（ r=-0.011， P=0.913）。细菌类型方面，19个钉-骨界面细菌培养阳性标本均为单一致病菌，最常见的致病菌为金黄色葡萄球菌（7个）；57个钉-软组织界面培养阳性标本中，单一致病菌感染51个，混合细菌感染6个。两个界面均培养阳性标本10对，其中4对标本细菌类型完全一致，1对标本细菌类型部分一致。共有82个细菌标本进行药物敏感试验，其中葡萄球菌感染占74.4%（61/82）。葡萄球菌的药物敏感试验结果显示：耐药前3名的药物分别为氨苄西林、苯唑西林及青霉素；而敏感药物前3名分别为万古霉素、替考拉宁及利奈唑胺，均未表现耐药。 结论:外固定支架钉-骨界面培养评估深部骨组织有无感染是必要的，钉-骨界面和钉-软组织界面同时培养可以为钉道感染的治疗提供更加全面的依据。

abstractsObjective:To evaluate the pin-bone interface surface culture in the diagnosis of pin tract infection in external fixation.Methods:A prospective observational study was conducted to enroll the patients who underwent either partial or complete removal of external fixators after external fixation at Department of Orthopaedic Trauma, Nanfang Hospital, Southern Medical University from June 2023 to September 2023. The secretions from the pin track (pin-soft tissue interface) were plated for bacterial culture. Additionally, the surface of the pins placed within the bone (pin-bone interface) was cultured directly with tryptic soy agar (TSA). Positive cases were subjected to additional analysis using qualitative microbial culture and antibiotic susceptibility testing. Comparisons were made between the cultural results derived from both interfaces.Results:The present study enrolled 23 patients [18 males and 5 females with an age of (37.3±17.6) years] and a duration of bearing external fixation of 8.1 (4.0, 11.3) months. A total of 212 samples were cultured. The positive rate of bacterial culture at the pin-soft tissue interface was 53.8% (57/106), significantly higher than that at the pin-bone interface [17.9% (19/106)] ( P<0.05). No correlation was found in the results of bacterial culture between the pin-bone interface and the pin-soft tissue interface ( r=-0.011, P=0.913). In terms of bacterial strains, single pathogenic bacteria were found in all the 19 positive samples cultured at the pin-bone interface, with Staphylococcus aureus as the most common pathogenic bacteria (7); of the 57 positive samples cultured at the pin-soft tissue interface, single pathogen infection was found in 51 and mixed bacterial infection in 6. Positive culture was found at both interfaces in 10 samples, of which identical bacterial strains were found in 4 and partially identical bacterial strains in 1. A total of 82 bacterial samples were subjected to drug sensitivity testing, of which 74.4% (61/82) were infected with Staphylococcus. The drug sensitivity test of Staphylococcus showed that the top 3 resistant drugs were ampicillin, oxacillin, and penicillin. The top 3 sensitive drugs were vancomycin, teicoplanin, and linezolid, all of which showed little resistance. Conclusions:Pin-bone interface culture of external fixators is a necessary evaluation of the infection of deep bone tissue. Simultaneous culture of pin-bone interface and pin-soft tissue interface can provide more comprehensive basis for the treatment of pin tract infection.