The purpose of this study is to compare infection rates when patients, elected for primary or aseptic revision THA / TKA, have a single intravenous antibiotic dose versus one single intravenous antibiotic dose in combination with intra-articular antibiotics. This is a prospective, randomized clinical survey on selected outcome measurements on 1834 subjects who will be recruited in a period of about 2 years.

Group A: patients receiving single dose of IV cefazolin 10-60 minutes before incision.

Group B: patients receiving a single dose of IV cefazolin 10-60 minutes before incision + a single dose of intra-articular vancomycin powder before articulation (hip or knee) closure.

Inclusion Criteria:

• Standard criteria for the implantation of primary total hip or knee replacement
• Revision of an aseptic THA or TKA.
• Adults >18 years of age
• Diagnosis of Osteoarthrosis (OA), Osteonecrosis (ON), Arthritis; or aseptic loosening of THA/TKA.
• Subject is willing to consent to participate in the study
• Subject is available for follow-up through at least 2 years
• Subject has met acceptable preoperative medical clearance and is free of or treated for medical conditions that would pose excessive operative risk.
• Subject who are fluent in English and / or French and able to understand their role in the study

Exclusion Criteria:

• Active, local infection or systemic infection.
• Participation in any other pharmaceutical, biologic or medical device clinical investigation
• Subjects with known allergy to vancomycin
• Subjects unable to consent
• Patient with skin pathology

Because of the nature of the intervention, it is impossible for the surgeon to be blinded. However, postoperative infection will be diagnosed by an independent co-worker, not involved in the surgery. Patients will be blind as they will not be aware if they had intra-articular vancomycin powder or not