Efficacy of Intra-wound Vancomycin in Prevention of Peri-prosthetic Joint Infection After Primary Total Knee Arthroplasty. A Prospective Double-Blinded Randomized Control Trial

Introduction: Peri-prosthetic Joint Infection (PJI) after total knee arthroplasty (TKA) is a devastating complication. Intra-wound vancomycin powder has been shown to reduce infection rates in spine surgery. Previous studies on the efficacy of local vancomycin powder in hip or knee arthroplasty are mostly retrospective case series. The aim of this prospective RCT was to evaluate the efficacy and safety of intra-wound vancomycin in preventing PJI after primary TKA. Methods: This study was a National Trial Registry-approved RCT of patients undergoing primary TKA. 1022 patients were randomized to the study group (n=507, received 2g intrawound vancomycin powder before arthrotomy closure) and control groups (n=515, no local vancomycin). The minimum follow-up was 12-months. The primary outcome was PJI rate. Secondary outcomes included surgical site infection (SSI) rates, incidence of revision for PJI/SSI, and incidence of wound complications. High-risk groups (Obesity and Diabetes) in both cohorts were also evaluated. Results: The overall infection rate in 1022 patients was 0.66%. There was no significant difference in PJI rate in the study group (0.2%) versus the control group (0.58%), p=0.264. Reoperation rates in the study group (N=4;0.78%) and Control (N=5;0.97%) and SSI rates in the study (N=1;0.2%) and control groups (N=2;0.38%) were comparable. The Vancomycin cohort however demonstrated a significantly higher number of minor wound complications(n=67;13.9%) compared to the control group (n=39;8.4%, p<0.05). There was no difference in PJI/SSI rates or minor surgical complications among high-risk groups and no cases of nephrotoxicity were reported in the study. Conclusion: Intra-wound vancomycin powder does not appear to reduce PJI/SSI rate in primary total knee arthroplasties, including high-risk groups. Although safe from a renal perspective, intra-wound vancomycin was associated with an increase in postoperative aseptic wound complications such as persistent wound drainage. Intra-wound vancomycin may not be effective in reducing the rate of PJI in primary TKA.