Background: Outcome of streptococcal prosthetic hip infection is often thought to be better than that caused by other pathogens. That supposition was not confirmed in our experience with group B streptococcal prosthetic joint infection.
Objective: We compared outcomes of group B streptococcal and other-pathogen prosthetic hip infections.
Methods: One hundred and thirty nine patients, 24 with group B streptococcal and 115 other-pathogen prosthetic hip infections, were included. The primary outcome was the time from surgical treatment to treatment failure, defined as relapse, infection- or treatment-related death. Secondary outcomes were the times from surgical treatment to relapse or any event (event-free survival). The cumulative incidence estimator was used to model primary and secondary outcomes. Multivariable regression analysis was used to determine a set of independent predictors of treatment failure.
Results: With a median follow-up of 22 months, treatment failed more frequently in patients with group B streptococcal prosthetic hip infections (hazard ratio, 4.88 [95% CI, 1.4-17], P=.012). Multivariable analysis retained the American Society of Anesthesiologist score and group B streptococcal infection as independent risk factors of treatment failure; event-free survival was lower for these patients (hazard ratio, 2.64 [95% CI, 1.2-6], P=.02).
Conclusion: Despite high antibiotic susceptibility, outcomes of group B streptococcal and other-pathogen prosthetic hip infection differ.