The number of total knee replacement
surgeries has soared 161.5% among Medicare participants over the past 20
years, a $5 billion annual tab that will continue to grow as the USA's
77 million Baby Boomers age, according to a large study out today.
wider use of knee replacement, on one hand, is good news for the
rapidly aging population. But while knee surgery eases pain from severe
arthritis and improves quality of life, the improvements "can be viewed
as another strain on government, individuals,and businesses struggling
with unremitting growth in health care costs,'' the authors report in
the Journal of the American Medical Association.
are living longer and want to be active," says lead author Peter Cram.
"They feel great after this surgery. They can hike in the mountains and
ski. They can be active with their grandchildren." The challenges, he
adds, are how to address post-surgery problems that can develop from
shorter hospital stays and in patients with other conditions such as
diabetes and obesity, and how to ensure doctors are not overusing a
"highly reimbursed procedure."
A knee replacement costs Medicare
about $15,000, costs that would be higher, the authors find, had
Medicare not taken cost-lowering measures of shortening hospital stays
and relocating many rehabilitations from in-patient clinics into the
patients' homes. However, those strategies can lead to problems down the
road for some patients and add costs and longer recovery times.
study is the first to evaluate trends and outcomes linked to total knee
replacement, the authors write, and includes a breakdown of expensive
factors that can lead to rehospitalizations and additional surgeries.
1991 to 2010, 3.27 million patients ages 65 and older had total knee
replacements and 318,563 had knee revisions, additional surgery to fix
problems. The researchers found the number of primary replacements among
Medicare patients increased from 93,230 in 1991 to 243,802 in 2010 (an
increase of 161.5%). The number of revisions increased from 9,650 to
19,871. Total knee replacement surgeries increased 99.2% (31.2
procedures per 10,000 Medicare enrollees in 1991 to 62.1 procedures per
10,000 in 2010.)
"We not only have more people
aging than we did 20 years ago, but we have more of these surgeries
being performed,'' says Cram, a physician at the University of Iowa
Carver College of Medicine in Iowa City.
During the same time
period, length of hospital stay decreased from 7.9 days to 3.5 days for
total knee replacement and from 8.9 to five days for revisions. However,
re-admissions have increased slightly for total knee replacements but
have increased more than 100% for revisions.
"Revisions are a
much more complicated surgery,'' says Cram, "and we need to be thinking
more about which patients are suited for them and which ones aren't."
an accompanying editorial, the authors say the yearly demand for total
knee replacements could be as high as 3.48 million procedures by 2030
and can potentially "decrease the allocation of health care resources
used by patients."
Yet the surgeries also "will be a driver of
health care costs,'' and steps need to be taken to address "predisposing
modifiable factors such as obesity and to advance efforts at early
intervention strategies to treat mild arthritis and to prevent
progression'' requiring surgery.