Background
As the number of total hip and knee arthroplasty cases increases, it is important to understand the burden of factors that impact patient outcomes of these procedures. This article examined the time trends in key demographics, clinical characteristics, comorbidity burden (Deyo-Charlson Comorbidity Index [CCI]), and presence of depression in patients undergoing primary total hip arthroplasty and total knee arthroplasty using population-based, all-payer inpatient database, California Healthcare Cost and Utilization Project, from 2007 to 2010.