NEW YORK (Reuters Health) -
Judging by the symptoms of people with knee arthritis,
one-third of knee replacement surgeries may be
inappropriate, according to a new study.
“We found that some patients undergo total knee replacement when
they have very low grade symptoms or minor knee arthritis,” lead
author Daniel L. Riddle from Virginia Commonwealth University in
Richmond told Reuters Health in an email.
The number of total knee replacement surgeries done each year more
than doubled between 1991 and 2010, leading some to question whether
the procedure is overused. This is hard to prove, though, since
symptoms like pain tend to drive the decision to proceed to surgery,
and different people perceive pain differently.
To get a better idea of what is going on, Riddle and his team
analyzed data from a study of about 4,800 people in the U.S. with
knee osteoarthritis or at high risk of the condition. During the
study period, 205 of them had total knee replacement surgery.
The researchers used criteria for knee replacements developed by Dr.
Antonio Escobar of Hospital de Basurto in Vizcaya, Spain and his
colleagues. Surgeries were judged to be appropriate, inappropriate
or inconclusive considering factors like a person’s range of motion,
pain and arthritis severity.
Based on prior studies, the researchers expected to find that about
20 percent of surgeries were inappropriate. What they found, though,
was that about 34 percent of patients had total knee replacements
that were deemed to be inappropriate.
For the most part, these patients had symptoms that were moderate at
worst and joint damage that was not widespread.
Less than half of knee replacements - 44 percent - were classified
as appropriate, according to findings published in Arthritis &
Rheumatology. That left about 22 percent in the inconclusive
category, which included patients with severe symptoms who were
either younger than 55 years old or had less joint damage and normal
Does this mean U.S. surgeons are performing too many knee
replacements on patients who don’t need them? Not necessarily. For
one thing, Riddle said, “the scientific content and the standard at
the time (this system) was developed is clearly different from that
in the U.S. in 2014.”
Doctors and patients need to do a better job deciding when it’s the
right time for a knee replacement, if ever, he added.
“I would encourage patients to gather and share information with
their family physician and surgeon to determine if they are good
candidates for the procedure,” Riddle said.
“The key issues, in addition to a reasonably healthy medical status,
are the extent of pain, extent of compromised function and extent of
knee osteoarthritis,” Riddle explained. “We have very good
prognostic data now and we know that persons with high levels of
psychological distress, minor knee osteoarthritis, serious (other
health conditions) and multiple joint arthritic disease are at
greatest risk of poor outcome.”
The authors say that research should now focus on developing a
system to separate inappropriate from appropriate knee replacements
that is based around U.S. patients.