Failure after two-stage exchange arthroplasty for treatment of periprosthetic joint infection: the role of antibiotics in the cement spacer

Introduction: Failure after a two-stage exchange surgery for periprosthetic joint infections (PJI) is high. Previous studies demonstrated that positive cultures at reimplantation are associated with failure afterwards. The aim of this multicenter study was to define the role of antibiotics in the cement spacer in relation to reimplantation cultures and subsequent failure. Methods: We retrospectively evaluated two-stage exchange procedures between 2000 and 2015. Culture-negative PJIs, cases in whom no cultures were obtained during reimplantation and cases without data on cement spacers were excluded. Results: 344 cases were included. The rate of positive cultures during reimplantation was 9.5% for cement spacers containing a glycopeptide (27/284) (with or without an aminoglycoside) versus 21.7% for those containing monotherapy with an aminoglycoside (13/60) (p 0.008), and was mostly attributed by a reduction in coagulase-negative staphylococci (CoNS) (17% versus 2%, p < 0.001). Failure rate was more than two-folds higher at 40.0% (16/40) in cases with positive cultures at reimplantation compared to 15.8% (48/304) for those with negative cultures (p < 0.001). Overall, a glycopeptide in the cement spacer was not associated with a lower failure rate (18% versus 23%, p 0.3), but was associated with lower failure due to CoNS (2.5% versus 13.3%, p < 0.001). Conclusion: In a two-stage exchange procedure for PJI, adding a glycopeptide to the cement spacer reduces the rate of positive cultures during reimplantation and is associated with a lower failure rate due to CoNS afterwards.