Author(s): Odette C El Helou*, Elie F Berbari, Camelia E Marculescu, Wissam I El Atrouni, Raymund R Razonable, Arlen D Hanssen, James M Steckelberg And Douglas R Osmon, MD; Mayo Clinic, Rochester, MN
Title: Outcome of Prosthetic Joint Infections due to Enterococci
Purpose: To determine the outcome of PJI due to enterococci treated with different surgical modalities as well as either monotherapy with a penicillin or vancomycin or dual therapy with penicillin or vancomycin and an aminoglycoside.
Methods: The medical records of all patients with enterococcal total hip or knee arthroplasty infectionbetween 1969 and 2000 at our institution were reviewed. The survival free of treatment failure (TF) was assessed by the Kaplan-Meier method. Wilcoxon test for equality of survival was used to compare outcome. Chi-Square or Fisher exact test were used to compare patient¡¦s characteristics. Patients were followed until death, failure, or loss of follow-up.
Results: 50 episodes of PJI due to enterococci occurred in 47 patients during the study period. The median f/u period was 1253 days (29, 4610 days). The median age at the time of diagnosis was 70 years (range, 32-89 years). 50 % (25/50) of episodes occurred in males. 48 % (24/50) involved a TKA. Patients received systemic steroids in 12 % (6/50) of episodes. Rheumatoid arthritis was present in 20% (10/50) of cases. One patient had concomitant enterococcal bacteremia. None had concomitant endocarditis. 46%, 34% and 10% of all episodes were treated with resection arthroplasty/Girdlestone (RA), staged exchange (SE) and debridement/retention (DR) respectively and the 2 year survival free of TF in each group was 82% (?? 10), 88% (?? 8), 80% (?? 18). 62 % (31/50) and 38% (19/50) received mono and dual therapy respectively and the overall 2 year survival free of TF in each group was 72% (??10) and 88% (?? 8) respectively (p = 0.1). There was no difference in the 2 year survival free of TF in patients who received mono vs dual therapy in the sub groups of patients who underwent RA, SE, and DR. The 2 groups (mono vs dual therapy) differed by age distribution (p = 0.004) and the development of VIII nerve toxicity (p = 0.0017).
Discussion: Enterococcal PJI is an uncommon infection at our institution, representing 1.5% of the total PJI.Adequate treatment of enterococcal PJI is mainly extrapolated from the treatment of enterococcal endocarditis.In this retrospective review, dual therapy with an aminoglycoside was given in 38% of PJI episodes with doses equivalent to the one used in endocarditis. Outcome did not differ between patients receiving dual versus mono therapy. Toxicity was more likely in the dual therapy group.