Clinical Outcome of Patients with Acute Periprosthetic Joint Infections Caused by Pseudomonas aeruginosa Compared to Other Gram-Negative Bacilli.

Pseudomonas aeruginosa is considered as more difficult to treat than other Gram-negatives in patients with acute periprosthetic joint infections (PJIs). However, clinical data to support this hypothesis are lacking. This retrospective multicenter cohort study included 39 patients with acute PJIs caused by P. aeruginosa and 84 control patients with another Gram-negative bacillus (i.e., Enterobacterales). Both groups were managed by surgical debridement, antibiotics, and implant retention (DAIR). Treatment failure within one-year follow-up was defined as prosthesis extraction, a clinical need for suppressive antibiotic treatment and/or PJI-related death. Distribution of affected joints, and revision versus primary arthroplasties, did not differ between groups. Most PJIs were polymicrobial (87% in cases, 81% in control patients, p = 0.451). Surgical and antibiotic management was similar between groups. Treatment failure did not differ between groups: 5/39 cases (12.8%) and 14/84 control patients (16.7%, p = 0.610). An acceptable success rate of acute PJI caused by P. aeruginosa when treated with DAIR was observed. This success rate did not differ compared to PJIs caused by Enterobacterales. Therefore, P. aeruginosa should not be considered a more difficult to treat microorganism compared to other Gram-negatives. No additional surgical or antimicrobial interventions are needed when patients can be treated with a fluoroquinolone.