Risk Factors for Surgical Site Infections Following Total Hip, Knee Replacement

Orthopedic surgeon with replacement hip
Researchers conducted a study to determine the risk factors associated with postoperative surgical site infection in patients who underwent total hip or knee replacements.

Obesity was found to significantly increase the risk for postoperative surgical site infection (SSI) among patients who underwent either total hip replacement (THR) or total knee replacement (TNR), according to results of a study published in Journal of Infectious Diseases and Epidemiology.

Researchers conducted a case-control study to assess the risk factors and frequency of postoperative SSI among patients who underwent THR or TKR at a hospital in Brazil between January 2007 and December 2011. Of a total of 390 patients included in the study 16 (4.1%) developed a postoperative SSI.

Among patients who underwent TKR, 11 developed a postoperative SSI. In addition, the researchers noted that obesity emerged as the most statistically significant risk factor for infection (P =.016). Preoperative bathing occurred in 37 (74%) patients and was associated with a decreased risk for postoperative SSI (P =.012). Among patients who underwent THR, 5 developed a postoperative SSI, and obesity and diabetes were the most representative risk factors, however, neither factor was statistically significant.

The infectious agents identified among all patients who developed a postoperative SSI were Staphylococcus aureus (33.3%), Acinetobacter baumannii (25%), Enterococcus faecalis (16.7%), Klebsiella sp (25%), Proteus mirabilis (16.7%), Enterobacter cloacae (8.3%), Escherichia coli (8.3%), and Serratia marcescens (8.3%). There were no deaths associated with infection, and 85.7% of patients underwent revision of prosthesis in two stages.

The researchers concluded that “the infection rate was approximately 4% in both procedures and probably reflects a sample composed of patients with comorbidities such as obesity, advanced age, and polymicrobial infection caused by bacteria [with the] most resistance.”


Braga ML, Henriques JF, Percope de Almeida MA, et al. Retrospective evaluation of post-hip arthroplasty and knee infections: frequency, associated risk factors and developments. J Infect Dis Epidemiol. 2021;7:220. doi.org/10.23937/2474-3658/1510220