Intraosseous Versus Intravenous Vancomycin in Tourniquetless Primary Total Knee Arthroplasty: A Randomized Trial

Background: Intraosseous (IO) administration of vancomycin at the time of total knee arthroplasty (TKA) has been shown to be safer and more effective than intravenous (IV) administration at preventing early periprosthetic joint infection. Previous studies have relied on tourniquet inflation to enhance local tissue concentrations and mitigate systemic release. Methods: A single-blinded, randomized clinical trial was performed on 20 patients (10 IV, 10 IO) undergoing primary TKA. The control (IV) group received weight-dosed vancomycin approximately 1 hour prior to the incision and weight-dosed cefazolin immediately prior to the incision. The interventional (IO) group received weight-dosed cefazolin immediately prior to the incision and 500 mg of vancomycin delivered via the IO technique at the time of the incision. Systemic samples for vancomycin levels were taken prior to the incision and at closure. During the procedure, tissue samples were taken from the distal femur, proximal tibia, and suprapatellar synovium. There were no differences in patient demographics or changes in serum creatinine from preoperative to postoperatively between groups. Results: Significant differences in systemic vancomycin levels (ug/mL) were found at the start of the case (IV = 27.9 ± 4.9 versus IO = 0 ± 0, P = .0004) and at the end of the case (IV = 19.6 ± 2.6 versus IO = 7.8 ± 1.0, P = .001). No significant differences were seen in the average vancomycin concentration in the distal femur (IV = 61.0 ± 16.0 versus IO = 66.2 ± 12.3, P = .80), proximal tibia (IV = 52.8 ± 13.5 versus IO = 57.1 ± 17.0, P = .84), or suprapatellar synovial tissue (IV = 10.7 ± 5.3 versus IO = 9.0 ± 3.3, P = .80). There were no complications associated with vancomycin administration in either group. Conclusions: This study demonstrates the utility of IO vancomycin in tourniquetless TKA with similar local tissue and significantly lower systemic concentrations than IV administration. Level of Evidence: Level 1 therapeutic randomized trial.