Periprosthetic joint infection (PJI) is a national health crisis and leads to very poor outcomes for patients undergoing elective joint replacement. Within the realm of elective total knee arthroplasty (TKA), various methods of infection prophylaxis are in place. These include sterile precautions, would/tissue handling, and antibiotic prophylaxis. With respect to the latter, various approaches have been utilized including intravenous and intraosseous administration of vancomycin, preoperatively. Intraosseous administration does require another wound and a specific device to administer. The investigators proposed that intraarticular injection of vancomycin is non-inferior to intraosseous administration, thus reducing wounds, time, and cost.

Inclusion Criteria:

• Any patient over the age of 18 years of age receiving treatment at UC San Diego Health
• Undergoing primary unilateral TKA
• Ability to provide consent

Exclusion Criteria:

• previous surgery on the knee (with the exception of arthroscopy)
• BMI > 35
• contraindication to receiving vancomycin, cefepime or cefazolin (ie, allergy, etc)
• diabetics with A1c>7.5% (unless controlled fructosamine)
• immunocompromised or immunosuppressed patients (HIV, Hepatitis C, end stage renal disease (ESRD), post transplant, chemotherapy or radiation therapy within 6 months of surgery, immunomodulating meducations)
• no history of active infections
• no history of chronic kidney disease