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 Table of Contents  
Year : 2020  |  Volume : 12  |  Issue : 1  |  Page : 1-5

Risk of infection following total knee arthroplasty in patients with asymptomatic bacteriuria: A meta-analysis

1 Hospital Clínica Ortopédica e Traumatológica, Orthopaedics and Traumatology Study Center; Hospital Manoel Victorino, Medical Residency in Orthopaedics and Traumatology, Salvador, Bahia, Brazil
2 Hospital Clínica Ortopédica e Traumatológica, Orthopaedics and Traumatology Study Center, Salvador, Bahia, Brazil
3 Faculdade de Tecnologia e Ciência, Medical School, Salvador, Bahia, Brazil
4 Hospital Manoel Victorino, Medical Residency in Orthopaedics and Traumatology, Salvador, Bahia, Brazil

Date of Submission31-Jan-2020
Date of Acceptance26-Mar-2020
Date of Web Publication26-Jun-2020

Correspondence Address:
Dr. David Sadigursky
Avenida Santa Luzia, 284. Edf. Horto Barcelona. Apartamento 901A, Zip Code: 40295-050, Salvador, Bahia
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jotr.jotr_8_20

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Introduction: In recent years, the treatment of asymptomatic bacteriuria (AB) is a topic approached in the orthopedic literature, with conflicting results about the need for treatment in the preoperative total knee arthroplasty (TKA). Objective: Systematic review with meta-analysis relating the presence of AB, as preoperative routine finding, to the risk of surgical site infection (SSI) following TKA, as well as the need for preoperative treatment of this condition. Methods: For the systematic review performed, five original articles were selected, following the PRISMA-p 2015. The keywords such as “asymptomatic bacteriuria” and “arthroplasty” or “joint replacement” or “joint infection” were used for the literature search in the databases of Bireme, PubMed, Medline, Science Direct, Google Scholars, and SciElo, between January and July 2018. Statistical analysis using the Mantel–Haenszel method and statistical test of relative risk with random effects were performed. Risks for publication bias were examined using a funnel plot. All analyzes were conducted using Review Manager version 5.3. Results: The results were inconclusive as to the increase in infection rates in patients undergoing TKA with AB. Conclusion: The study showed that the treatment of AB with antibiotics in the TKA preoperative period remains controversial due to the lack of data that reinforce this hypothesis.

Keywords: Arthroplasty, bacteriuria, infection, knee

How to cite this article:
Sadigursky D, Sousa MD, de Jesus LR, Neto JM, Lobão DM, Azi ML. Risk of infection following total knee arthroplasty in patients with asymptomatic bacteriuria: A meta-analysis. J Orthop Traumatol Rehabil 2020;12:1-5

How to cite this URL:
Sadigursky D, Sousa MD, de Jesus LR, Neto JM, Lobão DM, Azi ML. Risk of infection following total knee arthroplasty in patients with asymptomatic bacteriuria: A meta-analysis. J Orthop Traumatol Rehabil [serial online] 2020 [cited 2022 May 22];12:1-5. Available from: https://www.jotr.in/text.asp?2020/12/1/1/287722

  Introduction Top

Total knee arthroplasty (TKA) started in 1974, when John Insall performed the first total condylar prosthesis, and it has been improved during the year.[1] In 2006, it was already a consolidated procedure, with 270 thousand primary prostheses being done in the USA,[2] with 3.48 million annual prostheses estimated for 2030.[3]

However, TKA postoperative infection is a devastating complication, associated with mortality, morbidity, and increased economic costs. Although it is well known that the presence of urinary tract infection (UTI) is associated with an increased risk of following arthroplasty infection, few studies have demonstrated the need of asymptomatic bacteriuria (AB) treatment in the preoperative period and its relation with the increase of postoperative infection.[4] Thus, the occurrence and importance of AB in patients subject to hip and knee arthroplasty are still debate.[1]

The primary objective of this systematic review and meta-analysis is to determine whether an increased risk of TKA postoperative infection in patients with AB takes place or not.

  Methods Top

For this systematic review and meta-analysis, a literature search was done using the terms and Boolean operators “asymptomatic bacteriuria” AND “arthroplasty” OR “joint replacement” OR “joint infection”, in Bireme, PubMed, Medline, Science Direct, Google Scholars, and SciElo databases. Only original articles, published from 2014, on were included, following PRISMA-P protocol (2015).[5]

The abstracts of all studies identified were evaluated by two of the authors and reviewed bytwo senior authors. The complete versions of the studies were evaluated on those considered potentially relevant for inclusion in this review and on those abstracts which generated doubts about their relevance for eligibility.

Studies which had evaluated TKA postoperative infection risk in patients whose urine laboratory analysis showed evidence of preoperative AB were considered eligible. Studies exclusively on arthroplasty of other joints, literature reviews, authors' opinions, case reports, and case series with reduced samples were excluded from the study.

Data from the studies in the complete versions were independently extracted by two authors. Any disagreements were settled by consensus. The quality of the study was evaluated based on the design of the study and its classification by Centre for Evidence-Based Medicine. The presence of AB within TKA preoperative period and the occurrence of surgical site infection (SSI) postarthroplasty were used as parameters for data extraction. AB was determined according to the Infectious Diseases Society of America (IDSA) definitions: asymptomatic individuals presenting two consecutive voided urine specimens with isolation of the same bacterial strain in quantitative counts ≥10,000 cfu/mL, for women, or single, clean-catch voided urine specimen with 1 bacterial species isolated in a quantitative count ≥10,000 cfu/mL, for men.[6] As all data we analyzed were drawn from published literature, no informed consent or ethical approval was needed.

The measure of association chosen was the relative risk (RR), under the Mantel–Haenszel method. Analyses were conducted using a random effects model once the analyzed studies presented different designs. Heterogeneity (I2) was estimated by the restricted maximum likelihood method. All analyses were conducted using the Review Manager (RevMan) [Computer program] Version 5.3. Copenhagen: The Nordic Cochrane Centre, the Cochrane Collaboration, 2014.

  Results Top

Database research led to 32 studies. Five of them fulfilled the inclusion criteria of the present systematic review and meta-analysis [Figure 1], comprising a total of 4,361 patients. The studies included in the final selection are detailed in [Table 1]. The chart presented in [Figure 1] shows how the study was guided.
Figure 1: Flowchart summarizing the study selection process

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Table 1: Cohort features included in the meta.analysis infection post arthroplasty with asymptomatic bacteriuria

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All five studies were analyzed, showing the period and populations of each one of them. One can notice that the risk of patients with AB to develop SSI in postoperative TKA is demonstrated in only two studies: Sousa et al. 2014[7] and Martínez-Vélez et al. 2016.[8] However, the other studies did not show risk association when compared to patients without AB.[1],[4],[9] The RR of infection for AB patients was 2.79 with a confidence interval (CI 95%) of 0.81–9.59, this result being translated as no statistical significance [Chart 1] and [Chart 2].

  Discussion Top

For patients under TKA preoperative period, urinary investigation routine before surgery is mandatory for the majority of hospitals, with urinary alterations very frequently being detected in patients who remain asymptomatic. At the present study, the results found do not prove, statistically, that the presence of AB increases the SSI risk (RR 2.79 CI 0.81–9.59). The results, consequently, are inconsistent so one can affirm that AB patients, evaluated through urine laboratory test, should be treated with antibiotics, during preoperative period as prevention against postoperative TKA infection.

Within the current surgery sphere, the relation between AB and postoperative TKA infection is controverted. There are two contrary fronts in that context: the first is based on evidence from recent studies which observed AB patients, diagnosed by urine biochemical analysis and uroculture, present an augmented postoperative complication risk when compared to the group which did not present urine test alterations; the other brings a question regarding urine investigations in asymptomatic patients once it has not been demonstrated any association between preoperative AB and the increase of post-TKA infection, when compared to the group without urine alterations. Regardless the heterogeneity of specialists' opinions, urine investigation remains a pattern protocol in various health centers.[7]

Currently, there are no studies focused on cost-effectiveness or guidelines from official organizations, such as the IDSA, regarding to routine urinary screening and antimicrobial therapy, including in asymptomatic cases, in patients to undergo arthroplasty.[7] Preventing infection brings the benefit of reducing inherent morbidity and mortality and patient suffering, treatment time and prolonged hospital stay, necessity of reoperations, and the high costs involved in the process.[10]

The European Association of Urology (EAU) presents a respectable consensus on urological infections that, although easy to read, is rarely used in clinical practice. Their recommendations suggest that AB is, in fact, an important risk factor in procedures which invade the urinary tract and violate the mucosa; hence, it must be treated. They also suggest that a urine culture should be performed before the interventions and the AB treatment should be performed preoperatively not only for urological surgery but also for other specialties.[11],[12]

However, the new results obtained in orthopedic prostheses surgeries show that AB is common among TKA candidates, representing a risk of periprosthetic infection.[6] Contrary to EAU beliefs, preoperative antibiotic treatment did not show any benefits, so there is no evidence that it should be recommended.[6],[8],[13]

According to the periprosthetic infection guidelines, UTI is a factor for urinary screening and treatment due to an infection risk.[6] Since the hospital has routine antibiotics prophylaxis as protocol, no risks would be added in the case of AB.[14] However, those are specialists' opinions, while there are meta-analyses showing lack of evidence in literature on TKA preoperative management, including its treatment, duration, and antibiotics of choice.[15]

Martínez-Vélez et al.,[8] in 2016, published a 48-month follow-up of 215 patients subjected to TKA, finding positive urine culture without symptoms in 11/215. Those 11 patients were divided into two groups. The first one with four patients to be treated and the control group with seven patients. Only one case of SSI was found in the group with AB treated with antibiotic therapy. However, the bacteria isolated in sample culture of the operatory wound was different from the one found in the preoperative urine culture. Thus, AB has a low prevalence in the study, and once periprosthetic joint infections secondary to urinary tract focus were not found, it lacks evidence to support AB as a risk factor for Surgical Site Infection (SSI).

Between 2011 and 2012, Bouvet et al.[4] assessed 510 patients (309 women and 201 men), with average age 69 (16–97 years), subject to lower limbs joint replacement (290 hips and 220 knees), whereas 182 (36%) presented AB during preoperative period, being  Escherichia More Details coli the main pathogen, and 181 (35%) presented augmented leukocytes in the urine laboratory test. The majority of patients (95%) received a single intravenous dose of antibiotics as perioperatory prophylaxis (cefuroxime 1.5 g). On the 3rd postoperative day, the urine analysis showed an increase of leukocytes count in 99 (19%) of patients and AB in 208 (41%). Only 25 patients (5%) developed a symptomatic urinary infection during their hospital stay or in the 3 subsequent months to surgery procedure. Two-third of the identified organisms were not related to those found during admission. All symptomatic infections were successfully treated with oral antibiotics with no single case of SSI. It was concluded that investigating with laboratory tests and treating asymptomatic urinary tract colonization, prior to articulation substitution, were unnecessary measures.

Sousa et al., in 2014,[7] analyzed a total of 2492 patients subjected to joint replacement, 1247 of whom were subjected to TKA. Approximately two-third of them (63.0%) were women and the average age was 68 years. AB was diagnosed in 12.1% of them, being 16.3% women and 5.0% men. The global rate of SSI in the population studied was 1.7% (43 of 2.497). The infection rate in the AB group was 4.3% (13 of 303), significantly superior to the rate 1.4% in the group without AB diagnosis, concluding with their study that AB may increase the occurrence of SSI during postoperative arthroplasty, suggesting the necessity for previous treatment in all cases.

Gou et al. (2014)[9] revised 739 primary arthroplasty patient records. A total of 131 patients presented AB results in preoperative evaluation (17.7%) and 7 of 739 patients were diagnosed with SSI during the postoperative period. AB diagnosed prior to TKA procedure was not confirmed as a risk factor for the infection occurrence of multivariate regression with odds ratio adjusted of 1.04 (P > 0.05). Hence, according to Gou et al. (2014),[9] AB presence must not be considered as a motive for postponement of total arthroplasty.

Bhadra et al., in 2011,[16] revised 400 patients who have undergone primary arthroplasty. Bacteriuria was present in 172 patients; there were three cases of prosthesis infection, but only one was related to AB. It was considered a motive for postponement only at the presence of comorbidity which increases the risk.

As demonstrated in this meta-analysis, up to this moment, there is no statistical proof that AB preoperative presence increases the SSI risk. Consequently, AB preoperative treatment indication or postponement or suspension of the proposed TKA surgery is not fomented by literature due to the presence of AB during preoperative evaluation.

As limitations for the present study, we can verify that the results found in the sample varied according to the hospital situations and different follow-ups. The lack of specific studies regarding AB investigated during TKA preoperative period, with similar local characteristics, may interfere in the results found. In spite of the wide sample of patients from various studies, many of them still present biases, making it difficult to conclude and interpret the results. Thus, although the results differ, many health institutions still opt for proceeding urinary study in all patients, including urine cultures, during the protocols of preoperative preparation.[14]

  Conclusion Top

From the studies analyzed in this systematic review with meta-analysis, due to insufficient evidence found, it was noticed that the necessity of treatment of AB, in TKA preoperative period, as a method of SSI prophylaxis, is not consolidated. As a consequence, it is fundamentally the continuity of investigation and new studies, with significant samples, so that one can establish whether the augmented risk of post-TKA SSI exists, at the preoperative presence of AB, standardizing the necessity or not for treatment under these conditions and elucidating possible flaws while conducing preoperative procedures in patients with that diagnostics.

Recognizing that TKA postoperative infection is a feared and severe surgical complication, resulting in permanent and potentially incapacitating damage to patients, measures which attenuate that condition are of great relevance.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Glynn MK, Sheehan JM. The signi cance of asymptomatic bacteriuria in patients undergoing hip/knee arthroplasty. Clin Orthop Relat Res 1984;(185):151-4.  Back to cited text no. 1
Singh JA. Epidemiology of knee and hip arthroplasty: A systematic review. Open Orthop J 2011;5:80-5.  Back to cited text no. 2
Slover J, Zuckerman JD. Increasing use of total knee replacement and revision surgery. JAMA 2012;308:1266-8.  Back to cited text no. 3
Bouvet C, Lübbeke A, Bandi C, Pagani L, Stern R, Hoffmeyer P, et al. Is there any benefit in pre-operative urinary analysis before elective total joint replacement? Bone Joint J 2014;96-B: 390-4.  Back to cited text no. 4
Moher D, Liberati A, Tetzlaff J, Altman DG; The PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Med 2009;6:e1000097.  Back to cited text no. 5
Grein JD, Kahn KL, Eells SJ, Choi SK, Go-Wheeler M, Hossain T, et al. Treatment for positive urine cultures in hospitalized adults: A three medical center survey of prevalence and risk factors. Infect Control Hosp Epidemiol 2016;37:319-26.  Back to cited text no. 6
Sousa R, Muñoz-Mahamud E, Quayle J, Dias da Costa L, Casals C, Scott P, et al. Is asymptomatic bacteriuria a risk factor for prosthetic joint infection? Clin Infect Dis 2014;59:41-7.  Back to cited text no. 7
Martínez-Vélez D, González-Fernández E, Esteban J, Cordero-Ampuero J. Prevalence of asymptomatic bacteriuria in knee arthroplasty patients and subsequent risk of prosthesis infection. Eur J Orthop Surg Traumatol 2016;26:209-14.  Back to cited text no. 8
Gou W, Chen J, Jia Y, Wang Y. Preoperative asymptomatic leucocyturia and early prosthetic joint infections in patients undergoing joint arthroplasty. J Arthroplasty 2014;29:473-6.  Back to cited text no. 9
Bozic KJ, Kurtz SM, Lau E, Ong K, Chiu V, Vail TP, et al. The epidemiology of revision total knee arthroplasty in the United States. Clin Orthop Relat Res 2010;468:45-51.  Back to cited text no. 10
Cai T, Mazzoli S, Lanzafame P, Caciagli P, Malossini G, Nesi G, et al. Asymptomatic bacteriuria in clinical urological practice: Preoperative control of bacteriúria and manegement of recurrente UTI. Pathogens 2016;5.  Back to cited text no. 11
Tan CW, Chlebicki MP. Urinary tract infections in adults. Singapore Med J 2016;57:485-90.  Back to cited text no. 12
Cortes-Penfield NW, Trautner BW, Jump RL. Urinary tract infection and asymptomatic bacteriuria in older adults. Infect Dis Clin North Am 2017;31:673-88.  Back to cited text no. 13
Parvizi J, Gehrke T, Chen AF. Proceedings of the international consensus on periprosthetic joint infection. Bone Joint J 2013;95-B:1450-2.  Back to cited text no. 14
Voigt J, Mosier M, Darouiche R. Systematic review and meta-analysis of randomized controlled trials of antibiotics and antiseptics for preventing infection in people receiving primary total hip and knee prostheses. Antimicrob Agents Chemother 2015;59:6696-707.  Back to cited text no. 15
Bhadra AK, Armstrong J, Ghazi CA, Malkani AL. Significance of Asymptomatic Bacteriuria in Knee and Hip Arthroplasty. AAOS; 2011.  Back to cited text no. 16


  [Figure 1]

  [Table 1]


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