High revision rates following repeat septic revision after failed one- stage exchange for periprosthetic joint infection in total knee arthroplasty

Aims The outcome of repeat septic revision after a failed one -stage exchange for periprosthet-ic joint infection (PJI) in total knee arthroplasty (TKA) remains unknown. The aim of this study was to report the infection- free and all- cause revision- free survival of repeat septic revision after a failed one -stage exchange, and to determine whether the Musculoskeletal Infection Society (MSIS) stage is associated with subsequent infection-related failure. Methods We retrospectively reviewed all repeat septic revision TKAs which were undertaken after a failed one -stage exchange between 2004 and 2017. A total of 33 repeat septic revisions (29 one -stage and four two-stage) met the inclusion criteria. The mean follow- up from repeat septic revision was 68.2 months (8.0 months to 16.1 years). The proportion of patients who had a subsequent infection-related failure and all- cause revision was reported and Kaplan -Meier survival for these endpoints was determined. Patients were categorized according to the MSIS staging system, and the association with subsequent infection was analyzed. Results At the most recent follow- up, 17 repeat septic revisions (52%) had a subsequent infection-related failure and the five- year infection- free survival was 59% (95% confidence interval (CI) 39 to 74). A total of 19 underwent a subsequent all- cause revision (58%) and the five-year all- cause revision- free survival was 47% (95% CI 28 to 64). The most common indica-tion for the first subsequent aseptic revision was loosening. The MSIS stage of the host status (p = 0.663) and limb status (p = 1.000) were not significantly associated with subse- quent infection-related failure. Conclusion Repeat septic revision after a failed one -stage exchange TKA for PJI is associated with a high rate of subsequent infection-related failure and all- cause revision. Patients should be counselled appropriately to manage expectations. The host and limb status according to the MSIS staging system were not associated with subsequent infection-related failure.