The use of pulsed electromagnetic fields (PEMF) in osteoarthritis (OA) of the knee preliminary report.

Magnets are widely used by arthritic patients for symptom control. Clinical benefits have been reported from the intermittent application 01 pulsed electromagnetic fields to osteoarthritic joi nts.’ However. puhl shed trials have used complex electromagnetic fields generated b eumhersomeexpensiveequipment. limiting true portability and widespread use. We report comparable beneficial effects using a continu ous sine ave input to 1-Ielmholz coils run on standard household eleetricit\. Fifteen patients with osteoarthritis of at least one knee as defThed by Altman 4 were drawn from the outpatient Adult Rheumatology prac tice of one of the authors (TDC). Patients had to be older than 18 years and symptomatic in the subject knee for at least one year. Pain had to be incompletely relieved by analgesics. nonsteroidal antiinliammatory drugs (NSAIDs) and phsical therapy. No new treatments intra—artieular injection into the subject Joint. PT. NSAIDs were allowed ss ithin a month of. and during the study. Stable regimes were continued. Pregnant and premenopausal women not using contraception were excluded, as were patients with pacemakers or medical problems judged unstable. Subjects applied the supplied magnet to the designated knee for three hours daily for thirty days. They then returned to the clinic for reevaluation, and to receise the second magnet, which was then similarly applied at home, Of the pairs of magnets sequentially used by each patient, one magnet (hereinafter referred to as the “active magnet”) consisted of 1-Ielmholz coils delivering a 0,4 milliTesla. peak to peak. electro magnetic field at 60 Hi. in a sine wave configuration (Fig I. i. The other magnet appeai-ed identical in all respects. hut the fields affecting the ioint s crc the earth’s magnetic field onl\ . plus ss hat es er stray fields the individual might encounter in daily life ‘‘mac— to. e magnet. Subjects were assigned randomly to receive either magnet first. The folloving data were collected at baseline, at 3t) day’ tend of treatment period \ Oh the first magnet. and at 60 days end of treatment period with the second magnet patients assessment of pain, and the patient’s assessment of function on a ten centimeter visual analog scale (VAS), minutes of morning stiffness of the subject knee, range of motion. tenderness on an ordinal scale ofOto 4 (0 no tenderness, 4 = withdrawal), swelling on an ordinal scale of (3 to 4, knee circumference in cm, and time in seconds for the patient to walk 50 feet, Neither the assessing physician nor the patient knew which magnets were act is e or not. Of the fifteen patients enrolled and randoniiied. there were tour curly withdrasn als from the eroup that receis ed the inact is e mac— net—one at three days and two at one week for lack of patient—