Introduction: Periprosthetic joint infection (PJI) is a common cause for reoperation after knee and hip arthroplasty surgery. Debridement, antibiotics and implant retention (DAIR) is recommended in early infections (< 4 weeks) and stable implants. Aims: To define the success rate of DAIR in early infections and to identify predictors for success. Material and methods: In a retrospective cohort study we included patients with hip- or knee arthroplasties reoperated for an early PJI at Danderyd Hospital 2007-2012. Logistic regression analysis was used to identify risk factors affecting success rate. Primary outcome variable was the success of the DAIR treatment. Secondary outcome variable vas risk factors for treatment failure.

Inclusion Criteria:

Patients treated with DAIR for early postoperative periprosthetic joint infection after knee- or hip arthroplasty surgery (<4-6 weeks postoperatively) at our institution between 2007-01-01 and 2012-12-01.

Exclusion Criteria:

Chronic or late presenting periprosthetic joint infection (>6 weeks postoperatively), acute hematogenous periprosthetic joint infection, when the periprosthetic joint infection diagnosis criteria according to American Musculoskeletal Infection Society (MSIS) 2011 definition of PJI definitions were not fulfilled and when the initial surgical treatment was with other treatment protocol than DAIR including one-stage revision and two -stage revision

Danderyd Hospital is a university hospital affiliated with the Karolinska Institute and is one of the four emergency hospitals in Stockholm, with a catchment area of approximately 500.000 inhabitants. The index cohort was extracted from the local in-hospital surgery database at the Department of Orthopaedic Surgery using ICD 10 coding and surgical intervention coding for PJI treatment.