A new study in JAMA finds that hospitals now are performing more than twice as many knee replacement surgeries as they were two decades ago, a trend that may be driving up health care costs in the United States.
For the study, University of Iowa Carver College of Medicine's Peter Cram and colleagues analyzed more than 3.5 million first-time and revised knee replacement procedures performed on Medicare patients between 1991 and 2010.
Altogether, they found that hospitals in 2010 performed 243,802 knee replacement surgeries, up from 93,230 in 1991. They also found that:
- The number of knee surgeries performed increased from 31.2 per 10,000 beneficiaries in 1991 to 62.1 per 10,000 beneficiaries in 2010;
- Length of stay decreased from 7.9 days in 1991-1994 to 3.5 days in 2007-2010; and
- 30-day readmission increased from 4.2% in 1991-1994 to 5% in 2007-2010.
Among revision surgeries, overall readmissions increased from 6.1% in 1991-1994 to 8.9% in 2007-2010. "I think there is definitely the hint in there that we are now discharging people so quickly that more of them are requiring readmission," Cram says.
According to the study, demand for knee replacement surgeries could reach 3.5 million a year by 2030.
The researchers attribute the potential increase in demand to various factors, including aging baby boomers who hope to maintain healthy and active lifestyles. They note that there has been an expansion in the types of patients who may benefit from replacements, and a rise in conditions that contribute to arthritis—namely obesity (Kutscher, Modern Healthcare, 9/25; Wang, Wall Street Journal, 9/26; Pittman, Reuters, 9/25).