Forecasting the burden of advanced knee osteoarthritis over a 10-year period in a cohort of 60–64 year-old US adults

SummaryObjectiveTo forecast the burden of symptomatic knee osteoarthritis (OA) in the elderly US population over a 10-year horizon.DesignUsing a computer simulation model of the natural history and management of knee OA combined with population-based data from the 2008 US Census we projected the 10-year burden of knee OA among persons 60–64 years of age. Knee OA incidence and progression rates were derived from national cohorts and calibrated to published literature.ResultsUsing national data we estimated that 13% of 14,338,292 adults 60–64 years old have prevalent symptomatic, radiographic knee OA. Among persons surviving the next decade, 20% will have symptomatic advanced (Kellgren–Lawrence [K–L] grade 3) or end-stage (K–L 4) knee OA. Prevalence of advanced knee OA will range from 10% among non-obese to 35% among obese persons. Our estimates show that a more sensitive imaging tool, such as magnetic resonance imaging (MRI), may increase the number of OA cases diagnosed by up to 94% assuming that 50% of all ‘pre-radiographic knee OA’ (K–L 1) has some evidence of cartilage degeneration seen on MRI.ConclusionsProjecting new and advanced cases of knee OA among persons aged 60–64 years over the next decade creates a benchmark that can be used to evaluate population-based benefits of future disease-modifying OA drugs that are currently undergoing testing at various stages.