Antibiotics With Low Preoperative Suspicion or Established PJI
Strong evidence supports that preoperative prophylactic antibiotics be given prior to revision surgery in patients at low preoperative suspicion for periprosthetic infection and those with an established diagnosis of periprosthetic joint infection of known pathogen who are undergoing reoperation.

Rationale

Preoperative prophylactic antibiotics mitigate the risk for surgical infection and PJI and thus should be administered prior to revision surgery in patients with low preoperative suspicion for PJI. Additionally, patients with an established diagnosis of PJI and a known pathogen from preoperative synovial aspirate who are undergoing surgery would also benefit from preoperative antibiotic prophylaxis. Two high quality studies (Bedencic et al. 2016, Tetreault et al. 2014) in hip and knee revision patients and two low quality knee studies (Ghanem et al. 2007, Burnett et al. 2010) found no significant difference in false negative rates in their study population when antibiotics were given before surgery versus after intraoperative cultures were obtained. Additionally, two moderate quality randomized controlled trials found that patients not given any antibiotic prophylaxis were at increased risk of PJI compared to those who were given antibiotics preoperatively (Carlsson et al. 1977, Hill et al.1981).

POSSIBLE HARMS OF IMPLEMENTATION
In the patient with a known diagnosis of PJI and an identified organism, there are no known associated risks or harms with this recommendation. It is  possible that implementing this recommendation could mask an occult PJI in a patient is undergoing revision for presumed aseptic causes of failure. In these patients, a preoperative evaluation should have established a low suspicion of PJI prior to undergoing revision surgery. The evidence would suggest that the ability to culture an organism from intraoperative specimens would not be affected by the preoperative antibiotic prophylaxis.

FUTURE RESEARCH
No indications for future research.