Risk Factors Related to Poor Outcomes in the Treatment of Non-conventional Periprosthetic Infection.

 To identify the main risk factors related to poor outcomes after the treatment for periprosthetic infection.  Medical records from 109 patients who underwent non-conventional endoprosthesis surgeries (primary and revision procedures) from January 1, 2007, to December 31, 2018, were retrospectively evaluated. In total, 15 patients diagnosed with periprosthetic infection were eligible to participate in the study. Variables including gender, age at diagnosis, affected bone, surgery duration, white blood cell (WBC) count before endoprosthesis placement, urinary tract infection during the first postoperative year, and time elapsed from endoprosthesis placement to infection diagnosis were related to outcomes using the Fisher exact test (for the bicategorical variables) or analysis of variance (ANOVA, for the tricategorical variables). The mean times from diagnosis to final outcome were compared using the Student -test.  These risk factors did not show a statistically significant correlation with the outcomes. The data revealed a trend towards a difference between the mean time for the onset of infection and the final outcome. Due to the limited sample, we believe that studies with larger cohorts can prove this trend.  We identified that the time from endoprosthesis placement to the onset of the symptoms of infection tends to be related to the outcome and evolution of the patient evolution during the treatment for periprosthetic infection. Although apparently correlated, other associated factors were not statistically linked to poor treatment outcomes.