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November 29th, 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.
A new study published in the December issue of Arthritis Care
& Research, 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.
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.
Source: John Wiley & Sons, Inc. |
