Age-adjusted Charlson Comorbidity Index as an effective tool for the choice between simultaneous or staged bilateral total knee arthroplasty

The choice between simultaneous and staged bilateral total knee arthroplasty (BTKA) remains controversial. Age-adjusted Charlson Comorbidity Index(CCI) is a promising tool for risk-stratification. We aimed to compare the outcomes between patients who underwent simultaneous and staged BTKA, stratified by age-adjusted CCI scores. We conducted this retrospective, single-surgeon case series from 2010 to 2020. This study consisted of 1558 simultaneous BTKA and 786 staged BTKA procedures. The outcome domains included 30-day and 90-day readmission and 1-year reoperation events. We performed multivariate regression analysis to compare the risk of readmission and reoperation following simultaneous and staged BTKA. Other factors included age, sex, body mass index, diabetes mellitus, rheumatoid arthritis, smoking, receiving thromboprophylaxis and blood transfusion. The rates of 30-day, 90-day readmission and 1-year reoperation following simultaneous BTKA was 1.99