• 
• 

Three Part Question

In [adults with OA] will [magnetic bands or bracelets] improve [symptoms and increase function]

Clinical Scenario

A 60 year old female patient has treatment for widespread generalised OA. Her friend peruses the shopping channel and wants to buy a magnetic bracelet as a gift. Your patient wonders if this is a waste of money or may help her pain. You investigate further.

Search Strategy

MEDLINE 1966-09/06, CINHAL 1982-090/06, AMED 1985-09/06, SPORTDiscus 1830-09/06, EMBASE 1996-09/06, via the OVID interface. In addition the Cochrane database and PEDro database were also searched.
(magnetic therapy.mp OR magnets) AND (osteoarthritis OR OA OR arthritis OR arthropathy OR arthrosis) LIMIT to human AND English language.

Search Outcome

1 systematic review had a paragraph on magnets. 3 RCTs were also found that fulfilled the three part question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Hinman, M.R., Ford, J., Heyl, H. 2002 USA	n=43 Chroninc pain in 1 or both knee joints due to degenerative changes. Magnetic pad around knee	Double-blind randomised controlled clinical trial	WOMAC	Improvement in pain and physical function in subjects wearing magnets over placebo.	Only 2 weeks long. n=43 Used uni-polar magnets (? does this have and effect over bi-polar) Blinding threatened.
			15m Walk	Slight improvement in gait speed but not statistically significant.
Wolsko, P.M., Eisenberg, D.M., Simon, L.S., Davis R.B., Walleczek, J., Mayo- Smith, M., Kaptchuk, T. 2004 USA	n = 29 Idiopathic or post traumatic OA Magnets in knee sleeve Group A = High strength magnets (active) Group B = Placebo magnets (placebo)	Randomised double blind placebo controlled pilot study	WOMAC	Increase wrap wearing time > median time/day in active and placebo group = improvement in all WOMAC subscales @ 6/52 than wearing < median time /day.	Pilot: n = 29 Decreased placebo effect due to small sample size.
			Change in 50m walk time	Superior results at 4 hours but not significant. No difference at 1 or 6 weeks
			VAS	Superior results at 4 hours but not significant. No difference at 1 or 6 weeks
			Global Ax of change	Superior results at 4 hours but not significant. No difference at 1 or 6 weeks
Harlow, T., Greaves, C., White, A., Brown, L., Hart A., Ernst, E. 2004 UK	n = 194 OA hip or knee Bracelets worn on ventral wrist Group A = Standard magnets Group B = Weak magnets Group C = Non-magnetic steel washers	Randomised placebo controlled trial	WOMAC A	@ 12/52 standard magnet group = greater pain reduction, than placebo but not different from weak magnet group.	Blinding threatened Manufacturing error = wide variability in strength of placebo, some = same strength as standard. Can not be certain whether data shows specific effect of magnets, a placebo effect or both. Sample patients = predominately white with severe OA (WOMAC greater than or equal to 8)
			WOMAC B	No difference between groups.
			WOMAC C	@ 12/52 standard magnet group = improvement in functioning, than placebo but not different from weak magnet group.
			VAS	Significant mean difference between standard magnets and placebo.
			Perceived monetary value of the bracelet	Participants estimate of the monetary worth did not differ significantly.
Ernst, E. 2005 UK	x1 Cochrane Review x3 RCT +1 other	Review	Pain	Improved on motion in those who had magnet therapy over placebo	x1 Cochrane and x2 studies looked at pulsed magnetic fields not static magnets
			Cochrane review	no definitive evidence of magnet efficacy
			Beneficial effects	x1 study
			Non beneficial	x2 studies

Comment(s)

- Differing results due to different type and strength of magnets used and length of treatment time. - Small sample sizes. - Difficulty maintaining blinding. - Studies that showed no effect on pain generally used weaker magnets (19-50mtesla)

Clinical Bottom Line

There is some contradictory evidence that magnetic bracelets maybe beneficial in relieving symptoms of OA Knee/Hip

References

1. Hinman, M.R., Ford, J., Heyl, H. Effects of static magnets on chronic knee pain and physical function: a double blind study Alternative Therapies July/Aug 2002. Vol 8. No 4. p50-55
2. Wolsko, P.M., Eisenberg, D.M., Simon, L.S., Davis R.B., Walleczek, J., Mayo- Smith, M., Kaptchuk, T. Double-blind placebo-controlled trail of static magnets for the treatment of osteoarthritis of the knee: results of a pilot study Alternative Therapies Mar/Apr 2004. Vol. 10. No. 2.
3. Harlow, T., Greaves, C., White, A., Brown, L., Hart A., Ernst, E. Randomised controlled trail of magnetic bracelets for relieving pain in osteoarthritis of the hip and knee. BMJ Volume 329 18-25 December 2004 p1450-1454
4. Ernst, E. Complementary or alternative therapies for osteoarthritis Nature Clinical Practice Rheumatology February 2006 Vol 2 No 2