Superior Clinical Results With Intraosseous Vancomycin in Primary Total Knee Arthroplasty

Background: Periprosthetic joint infection (PJI) remains a feared complication after total knee arthroplasty (TKA). This study reports updated outcomes of the incidence of PJI, adverse reactions, and complications of our cohort with increased clinical follow-up of our previous study reported in 2021. Methods: A retrospective review of 1,923 knees that received either intravenous (IV) or intraosseous (IO) vancomycin during primary TKA between May 2016 and May 2023 with a minimum 90-day follow-up (mean 913 ± 611 days). There were 564 cases in the IV group and 1,359 in the IO group. The IV group received a weight-based dose of vancomycin before incision, and the IO group received 500 mg of vancomycin in the proximal tibia after tourniquet inflation. All patients received a weight-based dose of IV cefazolin perioperatively. The 2018 International Consensus Meeting criteria were used to diagnose PJI. Acute kidney injury (AKI) was defined as a creatinine increase of 0.3 mg/dL. Results: The IO group demonstrated a significantly lower incidence of PJI compared to the IV group at 90-day (0.5 versus 1.6%, P = 0.018), 1-year (0.7 versus 1.8%, P = 0.048), and 2-year (0.9 versus 2.4%, P = 0.032) follow-up. Additionally, there was a lower incidence of nonoperative wound complications requiring oral antibiotics in the IO group at 30-day (2.3 versus 4.3%, P = 0.023) and at 90-day (2.5 versus 5.4%, P = 0.003) follow-up. There was a lower incidence of AKI in the IO group (1.6 versus 3.2%, P = 0.078), but this did not reach statistical significance. There was no difference in the incidence of deep vein thrombosis, pulmonary embolism, or operative wound complications. Conclusions: Intraosseous vancomycin demonstrated superior clinical outcomes over IV vancomycin with a reduced incidence of PJI at 90-day, 1- and 2-year follow-up after primary TKA. Additional benefits of IO vancomycin were a reduction in nonoperative wound complications through 90-day follow-up and a nonstatistically significant reduction in the incidence of AKI.