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. In the case of bone healing, PEMF uses directed pulsed magnetic fields through injured tissue. This is believed to stimulate cellular repair. The FDA has approved several such stimulation devices. These devices provide a complementary solution that may aid in bone repair.

History

Although electromagnetic therapy became widely adopted in Western Europe, its use was restricted to animals in North America. Veterinarians became the first health professionals to use PEMF therapy, usually to heal broken legs in racehorses. Professional sports doctors then decided to experiment with veterinarian devices off label on professional athletes which ultimately led to legally licensed devices for human use in the United States - but under strict stipulations that it was only to be used for non-union bone fractures under a medical prescription from a licensed doctor.

In 1979 the FDA approved non-invasive devices using pulsed electromagnetic fields designed to stimulate bone growth.

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.

On 10/13/2015 the FDA reclassified PEMF devices from their existing Class 3 category to a Class 2 status. This change reduces the regulatory burden on manufacturers of PEMF devices that request FDA clearance to market their devices.

Today, there is a wide variety of professional and consumer PEMF devices that are sold on the internet as wellness devices. The companies that sell and manufacture them make no claims as to their effectiveness mainly to bypass medical device regulations and approvals. They often consist of full body mats and pillows that contain coils of wire that are energized by controller units that will "pulse" magnetic fields through the body.

Use

Delayed- and non-union fractures

In 1974 it was demonstrated that a pulsed magnetic field applied across the site of a bone fracture can accelerate the healing process (Bassett et al., 1974). The mechanism of osteogenesis is not clear; however, the use of PEMF therapy as an adjuvant therapy for delayed- and non-union fractures was supported by empirical evidence collected through clinical studies. While PEMF therapy may offer some benefit in the treatment of fractures, the evidence is inconclusive and is insufficient to inform current clinical practice.

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. Fukada’s and Yasuda’s discovery of the electric potential of bone provided evidence of electricity’s effect in promoting osteogenesis (bone growth), particularly in long bone non-unions. 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 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. Since that time, electrical stimulation has been shown to significantly increase the probability of bony arthrodesis in spinal fusions.

Depression

Transcranial magnetic stimulation is FDA approved since 2011 for use on patients that failed to respond to antidepressants. Weak magnetic stimulation of the brain is often called transcranial pulsed electromagnetic field (tPEMF) therapy. Early hints of efficacy of tPEMF as antidepressant came from observations that bipolar patients improved their mood after a magnetic resonance spectrogram, an approach which has been labeled LFMS. Studies in rodents have shown behavioural effects of tPEMF that are consistent with antidepressant effects. In humans, the treatment is usually given once or twice daily for two or more weeks.