Purpose of this study is to compare the efficacy of intravenous and intraosseous antibiotic administration techniques during tourniquetless total knee arthroplasty.

Primary Objective: Comparable levels of vancomycin will be found in distal femur, proximal tibia, and periarticular soft tissues, as well as in systemic levels, between the intravenous and intraosseous administration groups.

Secondary Objective: Compare 30- and 90-day post-operative complication rates (infection) between the control (standard IV administration of vancomycin) versus the interventional group (intraosseous administration of vancomycin). The research team hypothesizes that there will be no difference in complication (infection) rates between groups

Inclusion Criteria:

• Patient is undergoing a primary total knee arthroplasty.
• Patient is able to understand the study design and intervention and gives informed consent to participate in the study. No LAR consents will be utilized for this study.
• Age >18 years.
• Total knee arthroplasty performed without the use of a tourniquet.

Exclusion Criteria:

• Previous surgery on the knee (including arthroscopic knee surgery)
• BMI above 35
• Contraindication to receiving vancomycin, cefepime, ancef, or other standard of care pre-operative antibiotic (allergy, medical issue, etc).
• Inability to locate the tibial tubercle or administer the IO infusion
• Refusal to participate
• Uncontrolled Diabetes Mellitus type 1 or 2, defined as Hemoglobin A1C >7.5.
• Immunocompromised or immunosuppressed patients (HIV, Hep C, End-Stage Renal Disease, dialysis, transplant, chemo/radiation treatment in last 6 months, and immunosuppresive medications)

• Participant will be blinded to their mode of vancomycin administration.
• Lab will be blinded to which group subject samples come from when doing concentration level testing.