Surgical site infection following elective orthopaedic surgeries in geriatric patients: Incidence and associated risk factors

The purposes of this study were to investigate the incidence of surgical site infection (SSI) following geriatric elective orthopaedic surgeries and identify the associated risk factors This was a retrospective two-institution study. Between January 2014 and September 2017, patients aged 60 years or older undergoing elective orthopaedic surgeries were included for data collection and analysis. SSI was identified through the review of patients' medical records for the index surgery and through the readmission diagnosis of SSI. Patients' demographics, characteristics of disease, surgery-related variables, and laboratory examination indexes were inquired and documented. Univariate and multivariate logistic analyses were performed to determine independent risk factors for SSI. There were 4818 patients undergoing elective orthopaedic surgeries, and within postoperative 1 year, 74 patients were identified to develop SSIs; therefore, the overall incidence of SSI was 3.64%, with 0.4% for deep and 1.1% for superficial infection. Staphylococcus aureus (25/47, 53.2%) and coagulase-negative staphylococci (11/47, 23.4%) were the most common causative pathogens; half of S. aureus SSIs were caused by Methicillin-resistant Staphylococcus aureus (MRSA) (12/25, 48.0%). Five risk factors were identified to be independently associated with SSI, including diabetes mellitus (odds ratio [OR], 3.7; 95% confidence interval [95% CI], 1.7-5.6), morbid obesity (OR, 2.6; 95% CI, 1.3-3.9), tobacco smoking (OR, 4.2; 95% CI, 2.1-6.4), surgical duration>75th percentile (OR, 1.9; 95% CI, 1.0-2.9), and ALB < 35.0 g/L (OR, 2.3; 95% CI, 1.3-3.4). We recommend the optimisation of modifiable risk factors such as morbid obesity, tobacco smoking, and lower serum albumin level prior to surgeries to reduce the risk of SSI.