The clinical effects of PEMF therapy in osteoarthritis

Pulsed electromagnetic fields (PEMF) have been widely used in the treatment of delayed union fractures for over a decade and there is a growing body of literature concerning the biological and clinical effects of such low frequency,

nonionizing forms of energy. Clinical responses have been reported in longstanding nonunion fractures, failed arthrodesis, avascular necrosis of the hips in adults and Legg-Perthes’s disease in children.

A device to generate PEMF installed in a body brace increased the success rate of lumbar fusions in a double-blind control study. There are also several reports of augmentation of peripheral nerve regeneration and function, and also of promotion of angiogenesis.
Patients with persistent rotator cuff tendinitis, refractory to steroid injection and other conventional measures, showed significant benefit compared to placebo treated patients. In clinical studies done over 17 years in over 200.000 patients treated safely with PEMF, no toxic effects have been reported.

The hard facts

The results of this prospective double-blind study of PEMF treatment shows beneficial effects in the amelioration of symptoms, subjective improvement in functional ability and decrease in objective findings in a small group of patients with OA (osteoarthritis). The benefit seemed to continue for at least the first month after the treatment was completed.
This application of PEMF therapy is not similar to any other physical modalities of treatment, such as ultrasound, TENS, diathermy, moxibustion, etc. The PEMF generated by the device used in our study differs from the device used in the treatment of unhealed fractures in that it generates a lower frequency

Mechanisms which have been suggested include some form of induced resonance of outer-shell electrons, an effect on cell membrane receptors or on other endogenous processes, such as experimental substantiation. Evidence exists that pulsed magnetic fields can modulate the actions of hormones, antibodies and neurotransmitters at surface receptor sites of a variety of cell types. Effects on fibroblast, chondrocyte and osteocyte metabolism and lymphocyte functions have been reported as well. Augmentation of mRNA and protein synthesis has also been reported in several tissue culture symptoms.
Although the factors responsible for the pain in patients with OA are varied and often uncertain in an individual patient, an attempt to delineate the mechanism of pain relief brought about by this form of therapy in relation to known biological effects of pulsed magnetic fields is quite certain.

Furthermore, this form of nonionizing radiation is not known to have any deleterious clinical effects despite the variety of metabolic changes that have been demonstrated in the laboratory experiments.

Conclusion

Several new therapeutic strategies have recently been introduced for the treatment of osteoarthritis, including cyclooxygenase-2 inhibitors, tetracycline derivatives, viscosupplementation with various preparations of hyaluronic acid, and oral chondroitin sulfate/glucosamine supplements. While some may provide symptomatic benefit, disease modification is somewhat uncertain.

Two clinical trials have been reported, demonstrating symptomatic benefit with pulsed direct current or low-frequency pulsed electromagnetic field (PEMF) exposure in human osteoarthritis. Thus, it has been demonstrated that exposure to PEMF enhances chondrogenic differentiation and the synthesis of cartilage extracellular matrix proteins.

References

1. Miner, W. K., & Markoll, R. I. C. H. A. R. D. (1993). A double-blind trial of the clinical effects of pulsed electromagnetic fields in osteoarthritis. J rheumatol, 20, 456-60.
2. Ciombor, D. M., Aaron, R. K., Wang, S., & Simon, B. (2003). Modification of osteoarthritis by pulsed electromagnetic field—a morphological study. Osteoarthritis and Cartilage, 11(6), 455-462.