2025 ISAKOS Biennial Congress Paper
Intramedullary Positive Tissue Culture Increases the Risk of Re-Infection Following One-Stage Septic Revision Total Knee Arthroplasty
Luigi Zanna, Florence ITALY
Min Jae Lee, MD, Hamburg GERMANY
Taner Karlidag, MD GERMANY
David Luo, MD, PhD, Hamburg GERMANY
Mustafa Citak, MD, Prof., MBA, Hamburg GERMANY
Helios ENDO Klinik Hamburg, Hamburg, GERMANY
FDA Status Not Applicable
Summary
A positive intramedullary culture sample is significantly associated with septic failure after one-stage exchange for PJI of the knee
Abstract
Background
Intraoperative acquisition of representative tissue samples is essential during revision arthroplasty of the infected total knee arthroplasty (TKA). While the number of intraoperative tissue samples needed to identify the organism is well described in the literature, there is still a paucity of evidence regarding the location of positive intraoperative samples and their correlation to postoperative outcomes.
Methods
There were forty-two patients who had septic failure following one-stage revision TKA for periprosthetic joint infection (PJI) who were identified between January 2009 to December 2017. They were matched to a control group of patients who had successful one-stage revision TKA without septic failure. The location of positive intraoperative tissue samples was categorized as: 1) soft tissue; 2) interface between bone and prosthesis; and 3) intramedullary. Chi-square t, Student’s t-, and Wilcoxon Mann- Whitney U-tests were used as appropriate. Univariate and multivariate logistic regression analyses were performed to evaluate predictors of septic failure.
Results
Weight > 100 kilograms (P = 0.033), higher Charlson Comorbidity Index (P < 0.001), and positive intramedullary cultures (P < 0.001) were associated with a higher risk of re-infection after one-stage revision TKA. A positive intramedullary sample carried a nearly five-fold increase in odds of re-infection (OR [odds ratio] 4.86, 95% CI [confidence interval] 1.85 to 12.78, P = 0.001).
Conclusion
A positive intramedullary culture sample is significantly associated with septic failure after one-stage exchange for PJI of the knee. Patients who had positive intramedullary cultures may benefit from longer postoperative antibiotic therapy for the treatment of one-stage exchange arthroplasty to minimize the risk of re-infection.