What Factors Cause Hip Reimplantation to Fail after a Two-Stage Revision Hip Arthroplasty ?

AbstrAct background: We analyzed the survivorship free-from-septic failure in a series of THA cases treated with a two-stage protocol at long-term follow-up, with a special focus on the relevance of positive frozen section and positive intraoperative culture taken during the reimplantation. Methods: We retrospectively reviewed data from 96 cases who met the Musculoskeletal Infection Society criteria for periprosthetic joint infection and who had undergone both stages of a two-stage protocol at our institution between 2008-2013. Mean follow-up was 90 months. Treatment failure was determined with a modified Delphi-based consensus definition. Kaplan-Meier estimate was used to determine survivorship free-from-septic failure. Log-Rank test was used to compare variables associated with septic failure. results: Survival free-from-septic failure was 82.65% at 2 years (95%CI 73.25%-88.99%), 80.40% at 5 years (95%CI 70.70%-87.17%) and 77.32% at 6-10 years (95%CI 66.90%-84.33%). Patients with a positive culture at reimplantation had significantly more septic failures than those without it (Log-Rank test, p=0.0208), while patients with a positive frozen section at reimplantation had significantly more septic failures than those without it (Log-Rank test, p=0.0154). conclusions: Reimplantations that remained at least 6 years without septic recurrences had a very low risk of further septic failure. Both positive frozen section and intraoperative culture at reimplantation were risk factors for septic failure.