Just one year ago, doctors and researchers alike were
puzzled by the fact that women who underwent hip-replacement surgery were
almost 30 percent more likely than men to need repeat surgery within the first
three years.
Because of ongoing negligence litigation against the
manufacturer of one hip-replacement model, the focus tended to be on the
replacement itself, rather than on the patients. That was until a study
of more than 35,000 patients found that, no matter what model was used, women
who received this type of orthopedic service experienced replacement failure
more often.
The statistic was all the more troubling because the
majority of the more than 400,000 Americans who undergo full or partial hip
replacement surgeries each year are women.
Co-author of the 2013 study, Dr. Art Sedrakyan, associate
professor of public health at Weill Cornell Medical College in New York City,
said that, although the overall risk of the surgery remains low, "What
we've observed is, regardless of size, women had higher rate of revision occurrence."
One year later, researchers may have found a treatment that
can lower the risk of joint-replacement failure for women overall. In other
words, while the 2013 research focused on hip replacement, new research
indicates there could be a way to help women avoid a second surgery after any
joint replacement. According to a new British
study published online in Annals of the Rheumatic Diseases, hormone
replacement therapy offers significant promise.
Implants fail for several reasons, but the most common is osteolysis, which results
from bone loss caused by inflammation that occurs when small particles from the
implant irritate the supporting bone.
In order to prevent this bone loss, researchers tried
administering bisphosphonates, the class of drugs typically used to treat
osteoporosis; drugs like Actonel, Fosamax and Boniva. However, bisphosphonates
are associated with rare but serious side effects, so they decided to look at
hormone replacement therapy (HRT) instead due to its ability to relieve
symptoms of menopause, including thinning bones.
They looked at the records of women undergoing a first hip
or knee replacement between 1986 and 2006. Of the 24,733 women who had joint
surgery, they selected 2,700 who had used HRT for at least six months before or
after the surgery and matched them with 8,100 nonusers. Then they followed the
two groups for at least three years.
At the end of the study, 168 women from the original group
had undergone revision surgery. After accounting for control factors such as
age, weight, the type of joint replacement, and other drugs the patients were
taking, results indicated that women who used HRT for at least six
months after the original joint replacement were 38 percent less
likely to need a repeat procedure than those who had not used HRT.
Results improved over time too. For those who continued
taking HRT for a year, odds of needing a second surgery decreased an additional
10%.
As
lead researcher, Dr. Nigel Arden, director of musculoskeletal epidemiology at
the University of Oxford in England, pointed out, "There is evidence that
drugs like hormone replacement therapy, used usually to prevent osteoporosis
and fractures, might have a beneficial effect on implant survival in patients
undergoing knee or hip replacement.”
"These
findings must be confirmed in further studies, but they are consistent with
previous reports by our group showing an association between use of other drugs
that have similar effects on bone and the risk of implant revision [surgery],”
he concluded.
Using
HRT for any length of time before surgery had no effect on bone loss
or implant failure. In fact, Dr. Arden suggests that pre-surgical HRT could
cause harm by preventing implants from anchoring properly to the bone. Additionally,
he notes that hormone therapy should be stopped six weeks before surgery to
reduce blood clot risk.
Even
post-operatively, there are still side effects and risks associated with HRT such
as blood clots and increased risk of certain cancers. Many women are reluctant
to try it for that reason. Study results notwithstanding, the question remains
as to whether the benefits related to joint replacement revision surgery outweigh
those risks.
Elena Losina, PhD, codirector of the Orthopedics and
Arthritis Center for Outcomes Research at Brigham and Women’s Hospital in
Boston, calls
the Oxford study “very well designed and executed using appropriate, modern
analytic methods.”
However, she adds, “As [the study authors] highlighted, in
order to consider these results more definitively in clinical practice, they
need to be confirmed and reproduced in a multicenter, randomized controlled
trial.”
Dr. Arden agrees. He points out that his study adds “a
relevant piece of information for women who have received a total knee or hip
replacement and are considering hormone replacement therapy for menopause.
[But] it is only proof of principle and shouldn’t actually influence
prescribing until [a randomized control trial] is performed.”
After
all, while the risk to women of a second surgery is higher than for men, it is
still small overall. Doctor Arden agrees that this is a consideration, but
suggests women look at HRT as part of their healthcare in general, not just
orthopedic services alone:
"Indeed,
this is only a small added benefit of hormone replacement therapy. However, it
is a relevant piece of information for women who have received a total knee or
hip replacement and are considering hormone replacement therapy for menopausal
symptoms.”
If you are a woman who has just begun seeking orthopedic
services for joint pain, or are already considering or have decided to undergo
joint replacement surgery, these study results are important.
If you are already considering HRT for other symptoms -
especially osteoporosis - discuss with your doctor whether or not
post-operative HRT would be right for you, or whether the HRT drugs you are already
taking should be discontinued prior to surgery, then restarted as part of your
recovery.
As a 229-bed acute care hospital located in the heart of
Slidell, LA, Slidell Memorial
Hospital provides access to orthopedic
services, as well as the latest treatments, technology and expert
physicians.
