Antibiotic Duration for Management of Surgical Site Infections
Moderate evidence supports that, in the setting of retained total joint arthroplasty, antibiotic protocols of 8 weeks do not result in significantly different outcomes when compared to protocols of 3 to 6-month duration.

Rationale

The optimal duration of antibiotic therapy is not known. There was one high quality study (Lora-Tamayo 2016) and two low quality (Puhto 2012, Siqueira 2015) studies that evaluated short term antibiotics vs long term antibiotics in the setting of infected total joint arthroplasties. Both studies showed no significant difference in resolution of infection according to treatment duration.

In the study by Lora-Tamayo 2016, patients with staphylococcal infection were treated with debridement and implant retention and then randomized to either eight weeks or three (hips) or six (knees) months of antibiotic therapy. Resolution of infection was similar in both groups.

In the Puhto 2012 study, which included patients with a variety of microbes, they compared short term (two months total for hips and three months for knees) to their previously used long term (three months for hips and six months for knees). Again, they found no difference in success.

While antibiotic duration may not impact likelihood of cure, long term suppression may reduce the risk of relapse for patients who are not cured (Siqueira 2015). The benefit of chronic antibiotic suppression in this low-quality study was only seen for patients with Staphylococcus aureus infection managed with implant retention.