Factors affecting range of motion following two-stage revision arthroplasty for chronic periprosthetic knee infection

Introduction: The purpose of this study was to evaluate factors that affect range of motion (ROM) following twostage revision arthroplasty as a treatment for chronic periprosthetic knee infection. Materials and methods: A total of 98 patients diagnosed with chronic periprosthetic joint infection (PJI) following primary total knee arthroplasty between January 2009 and December 2019 and then underwent two-stage revision arthroplasty were reviewed retrospectively. Multiple regression analysis was performed to evaluate the factors that affect ROM after two-stage revision arthroplasty. ROM after two-stage revision arthroplasty was used as a dependent variable, while age at the time of surgery, ROM at PJI diagnosis, ROM after the first-stage surgery, the interval between the first-stage surgery and the second-stage surgery, whether a re-operation was performed before the second-stage surgery, culture results (culture negative or culture positive), and body mass index (BMI) were used as independent variables. Results: Multiple regression analysis (R 2 = 0.843) revealed that among the independent variables, ROM (β = 0.604, P < 0.001) after the first-stage surgery, whether a re-operation was performed before the second-stage surgery (β = - 8.847, P < 0.001), the interval between the first-stage surgery and the second-stage surgery (β = - 0.778, P = 0.003), and BMI (β = - 0.698, P = 0.041) were associated with ROM after two-stage revision arthroplasty, the dependent variable. Conclusions: In two-stage revision arthroplasty for chronic periprosthetic knee infection, ROM after the first-stage surgery, whether a re-operation was performed before the second-stage surgery, the interval between the first-stage surgery and the second-stage surgery, and BMI were found to be factors that were associated with ROM after twostage revision arthroplasty.