通过比较术前无症状性菌尿(ASB)患者与术前无感染患者，行初次人工关节置换术后，假体周围感染(PJI)的发生率的差异情况，探讨术前ASB与PJI发生的相关性，为术前ASB的处理方法提供依据。

回顾性分析2015年1月至2018年12月期间，西安交通大学第二附属医院骨科1 294例行初次人工关节置换患者，明确诊断ASB的患者共132例(患病率10.2%)，非ASB患者共1 162例(89.8%)。排除标准：既往有泌尿系统疾病，或者术前有尿道感染症状的患者，合并其他部位感染的患者。将ASB患者分为两组，治疗组和未治疗组。出院后患者随访≥12个月，以术后发生PJI为临床结局。将临床特征因素(包括年龄、性别、手术部位、是否合并糖尿病、是否肥胖)以及有无合并ASB纳入单因素分析，PJI患者假体周围分泌物行细菌学培养并与尿培养的结果进行对比。

在ASB组中PJI发病率为4.6% (6/132)；非ASB的患者共15例，PJI发病率为1. 3%(15/1 162)，ASB组的PJI发生率明显高于非ASB组(χ²＝7.864，P＝0.005)。单因素分析结果显示PJI组合并ASB患者的占比高(P<0.05)，而PJI患者和非PJI患者在年龄、性别、手术部位、是否合并糖尿病、是否肥胖方面，差异均无统计学意义(均为P>0.05)。ASB患者中治疗组、未治疗两组术后PJI发生率分别为4.7%(3/64)、4.4%(3/68)，两组差异无统计学意义(P＝1)。ASB患者术前尿培养以革兰阴性杆菌多见，尤其以大肠埃希菌为主，而PJI感染病原学以革兰阳性球菌多见。在PJI中分离的微生物与所有ASB患者术前尿培养物中的微生物均不相符，且没有其他因素与革兰氏阴性感染显著相关。

ASB患者在人工关节置换术前使用抗生素的情况下，并不会显著降低术后PJI的发生率。而且感染患者尿培养的细菌与PJI伤口局部培养的细菌不一致，也不支持PJI与ASB有直接关系。因此ASB患者术前针对ASB的抗生素治疗并不是必要的。

To investigate the correlation between preoperative ASB and PJI after the initial artificial joint replacement by comparing the incidence of periprosthetic infection (PJI) between patients with preoperative asymptomatic bacteriuria (ASB) and patients without preoperative infection after primary arthroplasty, and to provide a basis for the treatment of preoperative ASB.

From January 2015 to December 2018, 1 294 patients with primary artificial joint replacement were analyzed in the Department of Orthopedics of the Second Affiliated Hospital of Xi′an Jiaotong University, and a total of 132 patients with a definitive diagnosis of ASB (prevalence of 10.2%) and 1 162 patients (89.8%) of non-ASB patients were confirmed. Exclusion criteria: patients with preoperative urinary tract infections, patients with previous urinary tract diseases, or other local infections. The ASB patients were divided into two groups, the treated group and the untreated group. The patients were followed up≥12 months after discharge, with postoperative PJI as the clinical outcome. Clinically characteristic factors (including age, sex, surgical site, presence of diabetes mellitus, obesity) and the presence or absence of ASB were included in the univariate analysis, and bacteriological cultures of periprosthetic secretions were compared with the results of urine cultures in patients with PJI.

The incidence of PJI in the ASB group was 4. 6% (6/132); while the incidence of PJI was 1.3% (15/1 162) in The non-ASB group. The results showed that the incidence of PJI in the ASB group was significantly higher than that in the non-ASB group (χ²=7.864, P=0.005). Univariate analysis showed that the proportion of PJI patients with ASB was higher (P<0.05). There was no significant difference between the patients with or without diabetes or obesity (all P>0.05). In the ASB patients, the incidence of postoperative PJI was 4.7% (3/64) in the treatment group and 4.4% (3/68) in the untreated group; there was no significant difference between the two groups (P=1). The preoperative urine culture of the patients with ASB was mostly Gram-negative bacilli, especially escherichia coli, while the etiology of PJI infection was mostly Gram-positive cocci. Microbes isolated in PJI did not match those in the preoperative urine cultures of all the ASB patients, and no other factor was significantly associated with Gram-negative infection.

The use of antibiotics before artificial joint replacement in ASB patients does not significantly reduce the incidence of postoperative PJI. Moreover, the bacteria cultured in the urine of infected patients may not be consistent with the bacteria cultured locally in the PJI wound, nor does it support a direct relationship between PJI and ASB. Preoperative antibiotic therapy for ASB in patients with ASB is not necessary.