Two-stage exchange arthroplasty remains the preferred surgical treatment method for patients with chronic periprosthetic joint infection (PJI). The success of this procedure is not known exactly as various definitions of success have been used. This study aimed at analyzing the difference in outcome following 2-stage exchange arthroplasty using different definitions for success.
A retrospective study of 703 patients with PJI who underwent resection arthroplasty and spacer insertion between January 1999 and June 2015 was performed. Chart review identified intraoperative cultures at the time of spacer, reimplantation, and any subsequent reinfections or surgeries following spacer insertion. After applying the exclusion criteria, a total of 570 patients were included in the analysis. Five definitions of treatment success were assessed: (1) Delphi consensus success, (2) modified Delphi consensus success, (3) microbiological success, (4) implant success, and (5) surgical success.
Of the 570 patients with PJIs, 458 were reimplanted at a mean of 4.1 months. Mortality was 13.9% with 6.7% occurring before reimplantation. Treatment success was highly variable depending on the definition used (54.2%-88.9%). In 19.6% of PJI cases, the Delphi consensus definition could not be assessed as reimplantation never occurred. Furthermore, 67.0% of these patients underwent reoperations, which may not be accounted for in the Delphi consensus definition.
Treatment success rates vary dramatically depending on the definition used at our institution. We hope these definitions can help bring forth awareness for standardized reporting of outcomes, but further validation and agreement of these definitions among surgeons and infectious disease physicians is crucial.