Evaluation of comorbidity scoring systems in patients undergoing knee arthroplasty.

Background: Ageing populations are increasing the demand for knee arthroplasty. Concurrently, the prevalence of medical comorbidities are rising too. The Self-Administered Comorbidity Questionnaire was developed to provide a patient's assessment of their own comorbidities whereas the American Society of Anesthesiologists grades and the Charlson Comorbidity Index utilise clinical evaluation to objectively measure perioperative morbidity and mortality risk.