Risk of Surgical Site Infection in Patients with Asymptomatic Bacteriuria or Abnormal Urinalysis before Joint Arthroplasty: Systematic Review and Meta-Analysis

Abstract

Background: Routine screening and treatment for pre-operative asymptomatic bacteriuria (ASB) before joint arthroplasty are controversial. This systematic review and meta-analysis aimed to evaluate the impact of ASB and other bacterial colonization markers (BCM) observed in abnormal urine analyses, such as positive nitrites, leukocyturia, or positive leukocyte esterase in the risk of surgical site infections (SSIs) of joint arthroplasty patients.

Methods: Studies published between 1970 and 2017 that reported data on SSI and prosthetic joint infection (PJI) in patients after joint arthroplasty of the hip, knee, or shoulder with pre-operative ASB or BCM were included. A meta-analysis with random effect model was performed.

Results: Eleven studies were included (29,371 patients and 35,323 joints). The main procedures were total hip replacements (53.3%) and the mean follow-up period was 21.5 months, with 12 months being the minimum time of follow-up. A total of 2,400 cases (9.5%) reported pre-operative BCM (15%) or ASB (85%). The proportion of SSI was higher in patients with ASB (2.3% vs. 1.1%) (p < 0.001) and was related to a higher risk of SSI (odds ratio [OR] 2.89; 95% confidence interval [CI] 1.36-6.17), however, in only six cases (12.7%) was the SSI micro-organism correlated with the urine culture. Finally, antibiotic treatment for ASB did not reduce the SSI risk (OR = 0.82; 95% CI 0.34-1.97).

Conclusions: Asymptomatic bacteriuria represent a relatively common finding among these patients and is related to a higher risk of SSI. However, the poor microbiologic correlation suggests that ASB could represent a surrogate marker for other conditions correlated with bacterial infection. Therefore, systematic urinalysis screening should be discouraged, whereas a complete risk assessment that considers comorbidities and past medical history should be promoted.

Keywords: Urgical Site Infection; asymptomatic bacteriuria; bacterial colonization markers; prosthetic joint infection.