Hip and knee arthroplasties in Catalonia [Spain] from 1994 to 2005

Objective: Hip and knee arthroplasties are the most frequent surgical procedures in Catalonia. The aim of this study was to describe changes in the rates of these procedures and in their characteristics between 1994 and 2005. Methods: We performed a cross-sectional study of total hip (THR) and knee (TKR) primary and revision joint replacement discharges using the Minimum Data Set (ICD-9-CM codes 81.51, 81.53, 81.54 and 81.55). Standardized THR and TKR rates by age and sex and revision burden were calculated and changing trends were analyzed through joinpoint regression. Four time periods were defined and patient and hospital stay characteristics were analyzed by comparing period 4 with period 1 through logistic regression models. Results: In THR, the rates per 10,000 inhabitants increased from 4.1 to 6.6 between 1994 and 2000. In TKR, rates increased from 2.6 to 15.5 between 1994 and 2005. Hip revision burden increased until 2001, whereas knee revision burden increased for the entire period. The main reason for surgery was osteoarthritis. In both THR and TKR, the number of patients aged 75 or older and comorbidity increased. Conclusions: The increase in the rates and the change in patients' profile may reflect broadening of the indication criteria for these procedures. The impact of the foreseeable increase in revision surgery could be reduced by developing systems to evaluate prosthesis survival and clinical practice guidelines.