Surgical site infections (SSI) are a significant clinical issue that requires the use of a great amount of resources. In particular, periprosthetic joint infections (PJIs) have potentially catastrophic effects on patients' health-related quality of life, function, healthcare costs, outcomes and medical implications. National surveillance estimates may under-report the true incidence and when considering the large number of total hip (THA) and total knee arthroplasty (TKA) procedures performed each year.

Patients who have a high-level of nasal bacteria have been found to have a risk of surgical site infection that is three to six times the risk compared with noncarriers and low-level carriers. The association between a patient's nasal carriage of S. aureus, specifically MRSA, and PJI has been demonstrated in a systematic review and confirmed in recent cohort studies. While this association seems to be well accepted, no mechanistic explanation has been provided for this association.

Inclusion Criteria:

• All patients undergoing revision total knee or total hip arthroplasty at our institution will be eligible

Exclusion Criteria:

• Patients included in other prospective studies

Participants who are undergoing revision total knee or hip arthroplasty by one of the joints surgeons at Rothman Orthopaedics