Pulsed electromagnetic field therapy

Drolet's 1990 Rhumart system, a PEMF device.

Pulsed electromagnetic field therapy (PEMFT), also called pulsed magnetic therapy, pulse magnetotherapy, or PEMF, is a reparative technique most commonly used in the field of orthopedics for the treatment of non-union fractures, failed fusions, congenital pseudarthrosis and depression.^[1] The FDA has cleared several such stimulation devices.^[2][3]

Use

Delayed- and non-union fractures

An old fracture with nonunion of the fracture fragments.

The mechanism of osteogenesis is not clear.^[4][5] While PEMF therapy is claimed to offer some benefit in the treatment of fractures, the evidence is inconclusive and is insufficient to inform current clinical practice.^[6]

Depression

Transcranial magnetic stimulation is FDA approved since 2011 for use on patients that failed to respond to antidepressants.^[7] Weak magnetic stimulation of the brain is often called transcranial pulsed electromagnetic field (tPEMF) therapy.^[8] The treatment is usually given once or twice daily for two or more weeks.^[8]

Other animals

Studies in rodents have shown behavioural effects of tPEMF that are consistent with antidepressant effects.^[9][10][11]

History

Electromagnetic field therapy has been in use since the invention of electricity. It was widely adopted in East and Western Europe but its use was restricted to animals in North America until recently.^[12] Veterinarians became the first health professionals to use PEMF therapy, usually to heal broken legs in racehorses.^[13]

In 2004, pulsed electromagnetic field system was approved by FDA as an adjunct to cervical fusion surgery in patients at high risk for non-fusion.^[13] On 10/13/2015 the FDA reclassified PEMF devices from their existing Class 3 category to a Class 2 status. PEMF devices that have been FDA cleared to make health claims require a doctor's prescription for use.

Although electricity’s potential to aid bone healing was reported as early as 1841, it was not until the mid-1950s that scientists seriously studied the subject. During the 1970s, Bassett and his team introduced a new approach for the treatment of delayed fractures, a technique that employed a very specific biphasic low frequency signal ^{[14][15][16][17]} to be applied for non-union/delayed fractures. The use of electrical stimulation in the lumbosacral region was first attempted by Alan Dwyer of Australia. In 1974, he reported successful initiation of graft incorporation in 11 of 12 fusion patients.^[18][19]

Wellness devices

The original PEMF devices consisted of a Helmholtz coil which generated a magnetic field. The patient's body was placed inside the magnetic field to deliver treatment. Today, the majority of PEMF wellness devices resemble a typical yoga mat in dimensions but are slightly thicker to house several flat spiral coils to produce an even electromagnetic field. A frequency generator is then used to energize the coils to create a "pulsed" electromagnetic field. Today, there is a wide variety of professional and consumer PEMF devices that are sold and marketed on the internet as FDA registered wellness devices.^[20] The majority are manufactured in Germany, Austria and Switzerland and are imported into North America as electric massagers or full body electric yoga mats. They are either placed on a massage table for clinical use or directly on the floor in the home to practice simple yoga postures. The companies that sell and manufacture them as "general wellness products" are not permitted to make medical claims of effectiveness in treating disease.^[21]

References

Further reading

• Vavken, Patrick; Arrich, Ferdi; Schuhfried, Othmar; Dorotka, Ronald (2009-05-01). "Effectiveness of pulsed electromagnetic field therapy in the management of osteoarthritis of the knee: a meta-analysis of randomized controlled trials". Journal of Rehabilitation Medicine. 41 (6): 406–411. doi:10.2340/16501977-0374. ISSN 1651-2081. PMID 19479151.