Risk of re-admission, reoperation, and mortality within 90 days of total hip and knee arthroplasty in fast-track departments in Denmark from 2005 to 2011

PURPOSE: To compare the risks of re-admission, reoperation, and mortality within 90 days of surgery in orthopedic departments with well-documented fast-track arthroplasty programs with those in all other orthopedic departments in Denmark from 2005 to 2011. METHODS: We used the Danish hip and knee arthroplasty registers to identify patients with primary total hip arthroplasty or total knee arthroplasty. Information about re-admission, reoperation, and mortality within 90 days of surgery was obtained from administrative databases. The fast-track cohort consisted of 6 departments. The national comparison cohort consisted of all other orthopedic departments. Regression methods were used to calculate relative risk (RR) of adverse events, adjusting for age, sex, type of fixation, and comorbidity. Cohorts were divided into 3 time periods: 2005–2007, 2008–2009, and 2010–2011. RESULTS: 79,098 arthroplasties were included: 17,284 in the fast-track cohort and 61,814 in the national cohort. Median length of stay (LOS) was less for the fast-track cohort in all 3 time periods (4, 3, and 3 days as opposed to 6, 4, and 3 days). RR of re-admission due to infection was higher in the fast-track cohort in 2005–2007 (1.3, 95% CI: 1.1–1.6) than in the national cohort in the same time period. This was mainly due to urinary tract infections. RR of re-admission due to a thromboembolic event was lower in the fast-track cohort in 2010–2011 (0.7, CI: 0.6–0.9) than in the national cohort in the same time period. No differences were seen in the risk of reoperation and mortality between the 2 cohorts during any time period. INTERPRETATION: The general reduction in LOS indicates that fast-track arthroplasty programs have been widely implemented in Denmark. At the same time, it appears that dedicated fast-track departments have been able to optimize the fast-track program further without any rise in re-admission, reoperation, and mortality rates.