Prosthetic joint replacement: should orthopedists check urine because it's there?

Remote infection has long been considered a risk factor for prosthetic joint infection (PJI), a dreaded complication for orthopedic surgeons and patients who require joint replacement. Symptomatic urinary tract infection has been suspected as a cause of PJI in such patients, with little supportive evidence. There is concern that asymptomatic bacteriuria (ASB) could be another cause and that frail, elderly patients needing joint replacement might not express or manifest symptoms of urinary tract infection, placing them at untoward risk of PJI. Such concerns often lead surgeons to more vigilant screening. Despite scant supporting evidence, preoperative screening with urinalysis and/or urine culture has been advocated to prevent ASB from causing PJI [1].Noting lack of clarity on the issue, David and Vrahas [2] advocated 8–10 days of perioperative treatment of ASB. Preoperative treatment of ASB is common in some quarters, and is often considered a standard of care. Should it be? To answer this question, several issues need to be addressed. First, does ASB itself constitute a risk for morbidity or mortality, or is it just a marker of vulnerability? In a seminal multicenter, observational study of ambulatory, elderly women, Abrutyn et al [3] found that 318 women with ASB were older, sicker, and had greater mortality than 1173 women without ASB. Multivariate analysis, however, showed that ASB was unrelated to mortality; in addition, treatment of ASB had no effect on mortality—early evidence that ASB is a marker of risk, rather than a risk factor itself. Second, how reliable is a finding of ASB? The accuracy, reproducibility, and value of urinalysis [1, 4] and urine culture [4–6] have all been called into question. Trautner [6] notes that ASB represents differing conditions among patient groups differing in age, sex, and genetic and mechanical risks, and is caused by organisms of variable relevance. In the setting of acute cystitis in women, isolating Escherichia coli from a voided specimen is highly predictive of E. coli in a concurrent catheterized specimen, whereas enterococci and group B streptococci are unreliable predictors and rarely cause cystitis by themselves [5]. Treatment of ASB is commonplace, but indications for treatment of ASB are few [4]. With the exception of pregnant women and patients about to undergo invasive bladder procedures, ASB should not be treated. Lacking sufficient data, Infectious Diseases Society of America guidelines do not address management of ASB preceding joint replacement surgery. So, does ASB affect risk of PJI? Ritter and Fechtman [7] cast doubt on this concept in 1987, prospectively studying preor perioperative ASB or urinary tract infection (UTI) in 277 patients undergoing hip or knee replacement. They found no correlation between PJI and any urinary tract complications. They buttressed their conclusions by retrospectively examining another 16 years of practice and found only a single episode of PJI occurring 20 months after ASB and concluded that ASB should not be a contraindication for total joint replacement. More recently, Cordero-Ampuero et al [8] surveyed urinalyses in 471 patients without urinary symptoms prior to hip arthroplasty. If urinalysis was abnormal, they obtained urine cultures and if ASB was detected, they randomized subjects to treatment or placebo. They determined that organisms found in the urine were dissimilar to organisms causing PJI and that no episodes of PJI could be linked to ASB. Furthermore, treatment of ASB had no effect on outcomes. Bouvet et al [9] found a similar Received 1 April 2014; accepted 2 April 2014; electronically published 9 April 2014. Correspondence: Robert A. Duncan, MD, MPH, Center for Infectious Diseases and Prevention, Lahey Hospital and Medical Center, 41 Mall Road, Burlington, MA 02458 (robert.a. [email protected]). Clinical Infectious Diseases 2014;59(1):48–50 © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals. [email protected]. DOI: 10.1093/cid/ciu243