Pulsed electromagnetic field (PEMF) is an electrical instrument used to generate specific kind of magnetic fields that can influence the physiology of the human body. Each magnetic pulse generated by PEMF stimulates a tiny electrical signal in the cells of the body resulting in stimulation of the repair process. PEMF is a non-invasive instrument with established safety. FDA approved devices of PEMF are available for stimulating the process of bone healing.
PEMF and bone
Healing of the injured tissues is a normal process, which does not require outside stimulation in most of the cases. However, healing process of bones is very slow, especially in elderly people and people with diabetes. Almost 8 million fractures are reported to occur in the United States annually; among which 5-10% fractures show delayed healing or incomplete healing.
1 PEMF can be used as an adjuvant physical therapy to fasten the union of the fracture. Beneficial effects of PEMF have also been observed in the healing of soft-tissues (tissue surrounding bone e.g. muscles, tendon, ligament, cartilage); suppression of inflammation, pain relief and facilitating motion in various musculoskeletal disorders. 2 Research work done on PEMF and bone healing US National Library of Medicine, maintained by the National Institute of Health, is a comprehensive online database that stores the research works published in reputed international journals. A search using keyword “PEMF bone” resulted in 159 articles, among which 70 articles were discussing the research commenced on human volunteers. Few important articles are discussed here.
1. Study of PEMF in patients with delay in union of tibial fracture (fracture of leg bone) 3 In this study, 44 patients (average age of 50 years) were involved. The patients were sufferings from delay in tibial fracture healing with conventional plasters. All the patients received PEMF therapy for 3 hours daily. At the end of 36 months, fractures were healed completely in 34 patients (77.4% of total population). The minimum time required for fracture union was 8 months and maximum time was 36 months. Probability of fracture union was higher with longer duration of therapy. The authors concluded that PEMF is an effective therapy for the patients not having fracture healing with conventional plasters.
2. Study of PEMF in cervical fusion 4 Cervical fusion or cervical spinal fusion is a type of surgery that is used to join two adjacent vertebrates for a variety of reasons like neck pain due to compressed cervical nerve root, injury, misalignment of vertebrates, etc. During cervical fusion surgery, a bone graft is attached to the vertebrates, which further facilitates fusion of the two vertebrates. The effect of PEMF therapy on the outcome of cervical fusion was evaluated in 323 patients with neck pain. Among them, PEMF therapy was given to 163 patients and remaining 160 patients did not receive PEMF therapy. After the 6 months from the surgery, more than 83% patients receiving PEMF therapy showed successful fusion; whereas the successful fusion rate in the patients not receiving PEMF therapy was only 68.6%. At the end of 12 months, fusion rate was 92.8% in the PEMF group compared to 86.7% in the non PEMF group. Thus, PEMF was found to be effective in fastening the growth of bone graft used in cervical fusion surgery.