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Link
http://www.sciencedaily.com/releases/2007/11/071129085737.htm
Long-term Improvement Seen With Hip
Replacement
ScienceDaily (Dec. 4, 2007) — Total
hip arthroplasty (THA), or hip replacement, is an
effective treatment for osteoarthritis (OA), but most
studies have only followed patients for up to one year.
Researchers examined patients after an average of eight
years following hip replacement and found a long-term
positive impact on their physical functioning.
Led by Professor Cyrus Cooper and Ms. Janet Cushnaghan
of the University of Southampton in Southampton, UK, the
study included 282 patients from two English health
districts who had OA and were placed on the waiting list
for a hip replacement between 1993 and 1995. It also
included 295 matched controls from the general
population.
At the start of the study patients were interviewed
about hip injury, pain, physical function, vitality and
mental health. In addition, their BMI was calculated,
their hands were examined for Heberden's nodes, an
indication of OA, and their hip X-rays were evaluated
for severity of OA. Between 2001 and 2004, they
completed a self-administered questionnaire asking if
and when they had undergone hip replacement, as well as
questions about their physical function, vitality and
mental health. Follow-up of the patients took place an
average of eight years following hip replacement.
The results showed that patients who were waiting for a
hip replacement had markedly worse physical functioning
than the controls but only small differences in vitality
and mental health at the start of the study. By the time
of the follow-up, the physical functioning of the OA
patients had improved (while that of the controls had
deteriorated) but their vitality had deteriorated. In
addition, better physical functioning at the start of
the study was associated with a greater decline at
follow-up, but higher BMI seemed to have no impact.
Those with more severe OA according to their X-rays
showed the most improvement in physical functioning.
"Our findings are consistent with a sustained beneficial
impact on physical functioning following THA for OA, but
we found no evidence for parallel improvement in
vitality or mental health," Professor Cooper stated. The
researchers noted that the study is limited because it
was an observational investigation as opposed to a
randomized controlled trial and information about the
patients' disease and surgical procedures was limited.
But this weakness was offset by the fact that the study
had a long follow-up interval and a relatively large
number of patients and controls. "Even when allowance is
made for possible confounding effects, the long-term
improvement in the physical functioning of the cases is
striking when set against the decline that occurred in
controls," the authors note, suggesting that the
benefits of hip replacement are substantial and
long-lasting.
Although some previous studies have suggested that hip
replacement benefits mental health as well, the current
study did not find this to be the case, possibly because
the mental health status of the patients at the
beginning of the study was no different from the control
group, even though they had greater physical
limitations. Regarding the finding that BMI did not
affect long-term physical functioning, the authors
suggest that surgeons are perhaps careful in selecting
obese patients for this procedure, but in any case a BMI
in the range of up to 30 should not be a deterrent to
hip replacement as long as the patient is healthy enough
to undergo surgery.
The authors conclude that the study adds to the
accumulating evidence of the long-term benefits of hip
replacement, especially in patients with more severe
changes seen on X-rays, and that perhaps these patients
should be given higher priority for the procedure.
Journal article: "Long-Term Outcome Following Total Hip
Arthroplasty: A Controlled Longitudinal Study," Janet
Cushnaghan, David Coggon, Isabel Reading, Peter Croft,
Patricia Byng, Ken Cox, Paul Dieppe, Cyrus Cooper,
Arthritis Care & Research, December 2007.
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