Changing Epidemiology of Distal Femur Fractures: Increase in Geriatric Fractures and Rates of Distal Femur Replacement

Abstract

Introduction: Distal femur fractures (DFFs) are associated with high complication and mortality rates in the elderly. Using the National Inpatient Sample and Medicare data, we describe trends in the incidence of DFFs by fixation type and associated healthcare costs. Methods: Annual population rates and volume of inpatient DFFs were estimated using Poisson regression with the US Census as a denominator. We used Current Procedural Terminology codes in Medicare patients to determine episode-of-care cost by treatment, classified as intramedullary nail, open reduction and internal fixation, and distal femur arthroplasty (DFR). Results: The annual incidence of DFFs in the United States is approximately 27.4 per 100,000. Admission for DFFs increased from 2002 to 2020, with the highest volume and rate in those aged 85 years and older. DFF incidence increased (1.95×) from 142 per 1 million (95% CI: 140 to 144) in 2006 to 281 per 1 million (95% CI: 278-284) in 2019. From 2012 to 2019, the percentage of DFFs treated by intramedullary nail increased from 6.8% to 8.4%, open reduction and internal fixation decreased from 89.9% to 76.6%, and DFR increased from 3.3% to 14.9%. DFR cost was significantly greater than other treatment choices across all years for initial inpatient admission costs and 90-day episode-of-care costs (all P < 0.0001). Conclusion: DFF volume has increased in the past 20 years, predominantly in elderly patients. Greater than 4.5× increase was observed in the proportion of geriatric DFFs treated with DFR during this study period. The total cost of DFR treatment was consistently greater than other surgical treatments.