Risk of second revision and mortality following first-time revision due to prosthetic joint infection after primary total hip arthroplasty: results on 1,669 patients from the Danish Hip Arthroplasty Register.

Background and Purpose:  Prosthetic joint infection (PJI) following total hip arthroplasty (THA) has a severe impact on patients. We investigated the risk of second revision and mortality following first-time revision due to PJI.
Methods:  We identified 1,669 first-time revisions including 416 treated with debridement, antibiotics, and implant retention (DAIR) from the Danish Hip Arthroplasty Register (DHR). First-time revision due to PJI was defined as a revision with ≥ 2 culture-positive biopsies for the same bacteria or re-ported as PJI to the DHR within 1 year after primary THA with non-PJI revisions as controls. We retrieved information on Charlson Comorbidity Index (CCI), death, cohabitation status, and cultures from intraoperative biopsies. The adjusted relative risk (RR) with 95% confidence interval (CI) was calculated by first-time revision (PJI or non-PJI). Patients were followed from first-time revision until end of study.
Results:  PJI was found in 140 of 280 patients having a second revision following any first-time revision. Of these 280 patients, 200 were treated with DAIR as second revision. Patients with first-time revision due to PJI had an increased risk of second revision compared with first-time revision for non-PJI with an adjusted RR for second revision due to any cause of 2.7 (CI 1.9-3.8) and second revision due to PJI of 6.3 (CI 4.0-10). The 10-year adjusted RR for mortality for patients with first-time revision due to PJI compared with non-PJI was 1.8 (CI 0.7-4.5).
Conclusion:  The risk of second revision was increased both for second revision due to any reason and due to PJI following first-time revision due to PJI. Mortality risk following first-time revision due to PJI was increased, but not statistically significant.