One hundred and twelve infected arthroplasties treated with 'DAIR' (debridement, antibiotics and implant retention): antibiotic duration and outcome

We describe treatment failure rates by antibiotic duration for prosthetic joint infection (PJI) managed with debridement, antibiotics and implant retention (DAIR). We retrospectively collected data from all the cases of PJI that were managed with DAIR over a 5 year period. Surgical debridement, microbiological sampling, early intravenous antibiotics and prolonged oral follow-on antibiotics were used. One hundred and twelve cases of PJI were identified. Twenty infections (18%) recurred during a mean follow-up of 2.3 years. The mean duration of antibiotic use was 1.5 years. Failure was more common after arthroscopic debridement, for previously revised joints and for Staphylococcus aureus infection. There were 12 failures after stopping antibiotics and 8 while on antibiotics [hazard ratio (HR) = 4.3, 95% confidence interval (CI) 1.4-12.8, P = 0.01]. However, during the first 3 months of follow-up, there were eight failures after stopping antibiotics and two while on antibiotics (HR = 7.0, 95% CI 1.5-33, P = 0.015). The duration of antibiotic therapy prior to stopping did not predict outcome. PJI may be managed by DAIR. The risk of failure with this strategy rises after stopping oral antibiotics, but lengthening antibiotic therapy may simply postpone, rather than prevent, failure.