Electromagnetic energy for knee osteoarthritis
- Systematic review
- Results
- Comment
The
pages of our newspapers offer all sorts of quackery for all sorts of medical
conditions. One suggested treatment is pulsed electromagnetic field therapy, in
which magnetic fields are pulsed on and off to supposedly promote tissue
healing, to relieve pain, and inflammation. Some reviews have been produced,
with equivocal results, perhaps due in part to the variable quality of trials
included. A new systematic review [1] provides a clearer picture.
Systematic
review
The
review used a Cochrane search strategy to find randomised trials of pulsed
electromagnetic field therapy in adults with knee osteoarthritis who had
clinical or radiological diagnosis. Any type of pulsed electromagnetic field
therapy was accepted, using validated patient-reported pain and function as the
outcomes.
Results
Five
studies with 276 patients met the inclusion criteria. They had good reporting
quality, all scoring 3 out of 5 points or better on a standard scale. Duration
of treatment was two to six weeks, with two using a visual analogue scale for
pain, and three using the WOMAC scale.
All
five trials reported pain outcomes (Figure 1). No single trial showed any
benefit of pulsed electromagnetic field therapy over placebo for pain, nor was
there any difference overall. Four trials measured function. One showed a
trivial improvement, but there was no improvement overall.
Comment
Despite
the small number of small trials, there was not a smidgen of clinical benefit.
It is good, though, that people have taken the trouble to test pulsed
electromagnetic field therapy in properly randomised trials.
