Projected increase in total knee arthroplasty in the United States - an alternative projection model

M. C.S. Inacio, E. W. Paxton, S. E. Graves, R. S. Namba, S. Nemes

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181 Citations (Scopus)


Objective: The purpose of our study was to estimate the future incidence rate (IR) and volume of primary total knee arthroplasty (TKA) in the United States from 2015 to 2050 using a conservative projection model that assumes a maximum IR of procedures. Furthermore, our study compared these projections to a model assuming exponential growth, as done in previous studies, for illustrative purposes. Methods: A population based epidemiological study was conducted using data from US National Inpatient Sample (NIS) and Census Bureau. Primary TKA procedures performed between 1993 and 2012 were identified. The IR, 95% confidence intervals (CI), or prediction intervals (PI) of TKA per 100,000 US citizens over the age of 40 years were calculated. The estimated IR was used as the outcome of a regression modelling with a logistic regression (i.e., conservative model) and Poisson regression equation (i.e., exponential growth model). Results: Logistic regression modelling suggests the IR of TKA is expected to increase 69% by 2050 compared to 2012, from 429 (95%CI 374-453) procedures/100,000 in 2012 to 725 (95%PI 121-1041) in 2050. This translates into a 143% projected increase in TKA volume. Using the Poisson model, the IR in 2050 was projected to increase 565%, to 2854 (95%CI 2278-4004) procedures/100,000 IR, which is an 855% projected increase in volume compared to 2012. Conclusions: Even after using a conservative projection approach, the number of TKAs in the US, which already has the highest IR of knee arthroplasty in the world, is expected to increase 143% by 2050.

Original languageEnglish
Pages (from-to)1797-1803
JournalOsteoarthritis and Cartilage
Issue number11
Publication statusAccepted/In press - 2017


  • Epidemiology
  • Incidence rates
  • Projections
  • Total knee arthroplasty

ASJC Scopus subject areas

  • Rheumatology
  • Orthopedics and Sports Medicine
  • Biomedical Engineering

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