Mortality and re- revision following single- stage and two- stage revision surgery for the management of infected primary knee arthroplasty in England and Wales

AimsWe compared the risks of re-revision and mortality between two -stage revision surgery and single -stage revision surgery among patients with infected primary knee arthroplasty. Methods Patients with a periprosthetic joint infection (PJI) of their primary knee arthroplasty, initially revised with a single -stage or a two -stage procedure in England and Wales between 2003 and 2014, were identified from the National Joint Registry. We used Poisson regression with restricted cubic splines to compute hazard ratios (HR) at different postoperative periods. The total number of revisions and re-revisions undergone by patients was compared between the two strategies.ResultsA total of 489 primary knee arthroplasties were revised with single -stage procedure (1,390 person-years) and 2,377 with two -stage procedure (8,349 person-years). The adjusted inci-dence rates of all -cause re-revision and for infection were comparable between these strat-egies (HR overall five years, 1.15 (95% confidence interval (CI) 0.87 to 1.52), p = 0.308; HR overall five years, 0.99 (95% CI 0.70 to 1.39), p = 0.949, respectively). Patients initially man-aged with single -stage revision received fewer revision procedures overall than after two -stage revision (1.2 vs 2.2, p < 0.001). Mortality was lower for single -stage revision between six and 18 months postoperative (HR at six months, 0.51 (95% CI 0.25 to 1.00), p = 0.049 HR at 18 months, 0.33 (95% CI 0.12 to 0.99), p = 0.048) and comparable at other timepoints.ConclusionThe risk of re-revision was similar between single-and two -stage revision for infected pri-mary knee arthroplasty. Single -stage group required fewer revisions overall, with lower or comparable mortality at specific postoperative periods. The single -stage revision is a safe and effective strategy to treat infected knee arthroplasties. There is potential for increased use to reduce the burden of knee PJI for patients, and for the healthcare system.