Positive bacterial cultures did not predict antibiotic treatment failure in patients with complex periprosthetic joint infection (PJI) undergoing 2-stage surgical revision and reimplantation, according to results of a retrospective single-center study published in Infectious Diseases Now.
Researchers included all consecutive patients who underwent 2-stage revision procedures for the management of PJI at a single center between 2015 and 2018. All patients underwent complete removal of the prosthesis, debridement and implantation of a gentamicin-based spacer, and antibiotic prophylaxis with cefazoline for 6 to 12 weeks or at a duration decided by the attending physician. After the spacer was removed, patients underwent debridement and reimplantation of a new joint prosthesis.
Perioperative tissue, bone, and joint fluid specimens were collected from all patients during both the first and second stages of the procedure. Following the procedure, patients with positive and negative bacterial cultures received antibiotic treatment for 6 weeks or 10 days, respectively. Logistic regression was used to assess predictors of positive bacterial cultures during a minimum follow-up period of 2 years.
There were 50 patients included in the analysis, of whom the median age was 69 (IQR, 62-77 years), 64% were men, and 48% had PJIs involving the hip. The most commonly isolated pathogens were Staphylococcus aureus in 36% of patients and coagulase-negative staphylococci in 24%.
Perioperative bacterial cultures obtained during the second stage of the procedure were negative for 80% and positive for 20% of patients. Compared with patients with negative cultures, those with positive cultures were more likely to have a prosthesis implant for an inflammatory disease (50% vs 10%) and less likely to have an implant for osteoarthritis (50% vs 90%).
The incidence density of antibiotic treatment failure was 0.07 (95% CI, 0.02-0.18) events per 1000 patient-days. Analysis of Kaplan-Meier survival curves showed no difference in the probability of antibiotic treatment failure on the basis of perioperative tissue culture positivity, with similar results noted in regard to the duration of antibiotic treatment following the procedure. A multivariate analysis showed that antibiotic treatment failure was not independently associated with perioperative tissue culture positivity after adjustments were made for potential confounders. Osteoarthritis (adjusted odds ratio [aOR], 0.09; 95% CI, 0.01-0.65; P =.02) and inflammatory diseases (aOR, 12.4; 95% CI, 1.46-1.53; P =.03) were independently associated with positive bacterial cultures at reimplantation, with similar results for the duration of antibiotic treatment after the second stage of the procedure.
This study was limited by its small sample size and heterogeneity in regard to the location of patients’ PJIs.
“Our findings suggest that with proper microbiological techniques (including automated grinding), cultures grow rapidly, and consequently, that post-reimplantation antibiotic [treatment] should not exceed 10 days,” the researchers concluded.
Anastasia S, Jean-Michel U, David LP, et al. Microbiology and antibiotics after second-stage revision of periprosthetic joint infections: a two-year follow-up cohort. Infect Dis Now. Published online June 24, 2022. doi:10.1016/j.idnow.2022.06.005