The Effect of Obesity on Revision Total Knee Arthroplasty: Functional Outcome, Ninety-Day Costs, Reoperations, Readmissions and Cost-Effectiveness

The demand for revision total knee arthroplasty (RTKA) is increasing due to obesity and an aging population. The purpose of this study is to evaluate the effect of different body mass index (BMI) categories on RTKA using a retrospective cohort analysis. The first part was to assess patients’ functionality post-RTKA. The second part was to determine the survival of RTKA and re-revision rate. The third part was to explore the complication and readmission rates, and to estimate the 90-day costs of RTKA. We found the most common indication for RTKA in super obese patients is infection, unlike other BMI categories, whose most common indication is aseptic loosening. The improvement after RTKA is comparable across all BMI cohorts. Our analysis showed that a BMI ≥45 kg/m2 increases the risk of infection and re-revision, but only super obese patients are at an increased risk of readmissions and therefore have higher 90-day costs