Microbiological Epidemiology in Patients Experiencing Microbiological or Clinical Failure Following Reimplantation After a Two-Stage Exchange Strategy for Hip or Knee Prosthetic Joint Infection (PJI)

BACKGROUND: Patients with late PJI are at risk for superinfection at the time of reimplantation. Different commercially available antibiotic-loaded cements (gentamicin, vancomycin, gentamicin+clindamycin [G+C], gentamicin+vancomycin [G+V]) could be used for the fixation of the new prosthesis and could be effective to treat or prevent superinfection. We aim to determine the microbiological epidemiology in patients experiencing failure following reimplantation to establish, based on the drug susceptibilities, which cement could be the most active. METHODS: Prospective cohort study including all patients with a two-stage exchange in 2013–2015. Microbiological failure was defined by positive culture at the time of reimplantation. Clinical failure was defined by patients with clinical signs of infection requiring a new surgery. RESULTS: We included 117 patients (median age 70 years). Fourteen patients (12%) experienced a failure: seven patients with microbiological failure (four CoNS, one P. acnes, one corynebacterium, and three Candida albicans); seven patients with a clinical relapse requiring a new surgery (three Enterobacteriaceae, two P. aeruginosa, one streptococcus spp., one CoNS, one P. acnes, one E. faecalis). Considering the use of a vancomycin-loaded cement, this antibiotic was inactive on Candida (n = 3) and Gram-negative isolates (n = 5). Considering the use of gentamicin, this antibiotic was inactive on Candida (n = 3) and five bacterial isolates. These five letter isolates were also not susceptible to Clindamycin. Considering the use of G+V, this combination was inactive on Candida (n = 3) and only one bacterial isolate (a gentamicin-resistant K. pneumonia). Consequently, the vancomycin-, gentamicin- and G+C-loaded cements may effectively treat or prevent 42.9% of superinfections, only. Conversely, the G+V-loaded cement may effectively treat or prevent 71.4% of them. CONCLUSION: Considering the commercially available antibiotic loaded: none of the Candida albicans superinfection could be locally treated, and the G+V-loaded cement could treat or prevent most bacterial superinfections. DISCLOSURES: T. Ferry, HERAEUS: Consultant, Speaker honorarium. S. Lustig, Heraeus: Consultant, Consulting fee