Michael A. Mont,Kimona Issa

Total hip and knee arthroplasties are major orthopaedic procedures that are reliable and cost-effective and deliver excellent long-term implant survivorships and clinical and patient-reported outcomes. These procedures also have other extensive medical and non-medical benefits for patients and for society. An analysis of 185,829 patients by Dall et al.proposed that working-age individuals in the United States who had undergone a total hip or total knee arthroplasty had a 20% to 28% increase in likelihood of employment, $4300 to $6200 higher mean annual income, six to twenty-two fewer missed work days each year, and a 24% decreased probability of receiving supplemental security income compared with adults with untreated musculoskeletal disorders. Thus, because of the success of these procedures in treating end-stage joint arthritis, total joint arthroplasties are being increasingly offered to younger, more active patients, as well as to those who have a higher body mass index. It is expected that the demand for these procedures will continue to rise in the future, and thus, studies that attempt to provide accurate trends and future projections may help orthopaedic surgeons and policy makers to better structure the health-care system for improvements in patient care.

The economic downturn in 2001, in conjunction with the terrorist attacks on the World Trade Center, and the recession in 2008 to 2009 have been associated with a higher rate of unemployed individuals and a lower national Gross Domestic Product (GDP) in the United States. All of these events might have impacted the number of lower-extremity total joint arthroplasties performed. Kurtz et al. used data from the Nationwide Inpatient Sample (NIS) and the National Health Expenditure from 1993 to 2010 in an attempt to better evaluate future trends on the number of total joint arthroplasties. These authors previously reported their projectionsusing the NIS database (1990 to 2003); however, in the present work, they attempted to update these outcomes and to evaluate the effects of the economic downturns during the past decade. They found that although the total number of primary and revision total hip and knee arthroplasties was reduced and/or plateaued during the recent downturns (especially in 2008 to 2009), overall the long-term growth trends for these procedures for the United States population were insensitive during these times. Kurtz and colleagues reported that the new model proposed a higher number of total hip arthroplasties and a lower number of total knee arthroplasties by 2020 compared with the results in their previous report in 2007. Among the economic indicators that were evaluated, the National Health Expenditure was found to have the strongest correlation in historical variance with the incidence of primary total joint arthroplasties (97% to 98%) and revision total joint arthroplasties (69% to 94%).