Risk factors for amputation in periprosthetic knee infection

Treatment for prosthetic knee replacement is becoming more common. Infection is an arthroplasty-related complication leading to prolonged hospitalization, multiple surgical procedures, permanent loss of the implant, impaired function, impaired quality of life and even amputation of the limb. Previous studies have evaluated the risk factors associated with periprosthetic knee infection, but scarce information related to risk factors associated with amputation in this group of patients is available. The purpose of this study was to identify risk factors for amputation in periprosthetic infected knee through a case–control study, analyzing patients treated from January 2012 to November 2016 in a hospital with a high incidence of this diagnosis. We included 183 patients with periprosthetic knee infection; 23 required amputation as definitive management (cases). We found that patients with surgical time >120 min (p = 0.01), surgical risk higher than two points according to the American Society of Anesthesiology score (p = 0.00), smokers (p = 0.04), obesity and diabetes mellitus (p = 0.00) had an increased risk of amputation.