The clinical dilemma of asymptomatic bacteriuria in orthopedic surgery: a systematic review and meta-analysis

Background: Periprosthetic joint infection (PJI) is one of the most serious complications after major orthopedic surgery, leading to significant morbidity, reoperation, and healthcare costs. Asymptomatic bacteriuria (ASB) is common in orthopedic surgical candidates and has been suggested as a potential risk factor for PJI, prompting many centers to perform routine preoperative urine cultures and administer antibiotics. Conflicting current guidelines highlight the urgent need for an updated synthesis of the evidence. Methods: This systematic review and meta-analysis were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic databases were searched from inception through July 2025. Eligible studies compared outcomes between patients with and without preoperative ASB. Relative risks (RRs) with 95% confidence intervals (CIs) were pooled using a random-effects model. Prespecified subgroup analyses were also performed based on antibiotic treatment status. Results: Sixteen studies (43 960 patients; 2702 with ASB) were included; ASB prevalence was 6.2%, and most studies used ≥10 5 CFU/mL to define ASB. Compared with non-ASB, ASB was associated with higher PJI risk (10 studies; RR 2.83, 95% CI 1.23–7.64; I 2 = 68%) and any surgical site infection (SSI) risk (16 studies; RR 2.87, 95% CI 1.33–6.22; I 2 = 82%). In subgroup analyses, elevated rates were observed mainly in treated ASB cohorts, whereas untreated ASB did not differ significantly from controls. Direct comparison of treated versus untreated ASB showed no protective effect of antibiotics (five studies; RR 1.01, 95% CI 0.48–2.11). Urine and surgical isolates were discordant in 84.1% (37/44) paired cases. Conclusion: This study found that patients with preoperative ASB undergoing major orthopedic surgery were associated with a higher rate of PJI and SSI, though this finding is characterized by clinical heterogeneity. Subgroup analyses demonstrated that targeted antibiotic treatment of ASB does not reduce this postoperative infection risk. Therefore, current evidence does not support routine screening and antibiotic treatment of ASB as an effective prevention strategy, necessitating future randomized trials with adequate power to provide definitive guidance.