The Brazilian Journal of Infectious Diseases The Brazilian Journal of Infectious Diseases
Braz J Infect Dis 2017;21:613-9 - Vol. 21 Num.6 DOI: 10.1016/j.bjid.2017.06.003
Original article
Infections after shoulder arthroplasty are correlated with higher anesthetic risk score: a case-control study in Brazil
Leonardo Hideto Nagayaa, Mauro José Costa Sallesb,, , Lucas Sadawo Chagas Takikawaa, Marcelo Fregonezea, Pedro Doneuxa, Luciana Andrade da Silvaa, Guilherme do Val Sellaa, Alberto Naoki Miyazakia, Sergio Luiz Checchiaa
a Faculdade de Ciências Médicas da Santa Casa de São Paulo, Departamento de Ortopedia e Traumatologia, São Paulo, SP, Brazil
b Faculdade de Ciências Médicas da Santa Casa de São Paulo, Departamento de Medicina Interna, Secção de Doenças Infecciosas, São Paulo, SP, Brazil
Received 11 March 2017, Accepted 11 June 2017
Abstract
Purposes

Shoulder arthroplasty (SA) has been performed by many years for the treatment of several conditions, including osteoarthritis and proximal humeral fractures following trauma. Surgical site infection (SSI) following Shoulder arthroplasty remains a challenge, contributing to increased morbidity and costs. Identification of risk factors may help implementing adequate strategies to prevent infection. We aimed to identify pre- and intra-operative risk factors associated with deep infections after Shoulder arthroplasty.

Methods

An unmatched case-control study was conducted to describe the prevalence, clinical and microbiological findings, and to evaluate patient and surgical risk factors for prosthetic shoulder infection (PSI), among 158 patients who underwent SA due to any reason, at a tertiary public university institution. Risk factors for PSI was assessed by uni- and multivariate analyses using multiple logistic regression.

Results

168 SA from 158 patients were analyzed, with an overall infection rate of 9.5% (16/168 cases). Subjects undergoing SA with American Society of Anesthesiologists (ASA) grade III or higher (odds ratio [OR]=5.30, 95% confidence interval [CI]=1.58–17.79, p<0.013) and presenting local hematoma after surgery (odds ratio [OR]=7.10, 95% confidence interval [CI]=1.09–46.09, p=0.04) had higher risk for PSI on univariate analysis. However, only ASA score grade III or higher remained significant on multivariate analysis (OR=4.74, 95% CI=1.33–16.92, p=0.016). Gram-positive cocci and Gram-negative bacilli were equally isolated in 50% of cases; however, the most commonly detected bacterium was Pseudomonas aeruginosa (18.7%).

Conclusion

This study provides evidence suggesting that patient-related known factors such as higher ASA score predisposes to shoulder arthroplasty-associated infection. Furthermore, unusual pathogens associated with PSI were identified.

Keywords
Orthopedic infection, Hemiarthroplasty, Total shoulder arthroplasty, American Society of Anesthesiologists score, Risk factor, Pseudomonas aeruginosa
Braz J Infect Dis 2017;21:613-9 - Vol. 21 Num.6 DOI: 10.1016/j.bjid.2017.06.003