OBJECTIVE.We conducted a randomized, double blind clinical trial to determine the effectiveness of pulsed electromagnetic fields (PEMF) in the treatment of osteoarthritis (OA) of the knee and cervical spine.

METHODS. Acontrolled trial of 18 half-hour active or placebo treatments wasconducted in 86 patients with OA of the knee and 81 patients with OA of the cervical spine, in which pain was evaluated using a 10 cm visualanalog scale, activities of daily living using a series of questions(answered by the patient as never, sometimes, most of the time, oralways), pain on passive motion (recorded as none, slight, moderate, or severe), and joint tenderness (recorded using a modified Ritchiescale).

Global evaluations of improvement were made by the patient andexamining physician. Evaluations were made at baseline, midway, end oftreatment, and one month after completion of treatment.

RESULTS.Matched pair t tests showed extremely significant changes from baseline for the treated patients in both knee and cervical spine studies atthe end of treatment and the one month follow-up observations, whereasthe changes in the placebo patients showed lesser degrees ofsignificance at the end of treatment, and had lost significance formost variables at the one month follow-up. Means of the treated groupof patients with OA of the knee showed greater improvement frombaseline values than the placebo group by the end of treatment and atthe one month follow-up observation. Using the 2-tailed t test, at theend of treatment the differences in the means of the 2 groups reachedstatistical significance for pain, pain on motion, and both the patient overall assessment and the physician global assessment. The means ofthe treated patients with OA of the cervical spine showed greaterimprovement from baseline than the placebo group for most variables atthe end of treatment and one month follow-up observations; thesedifferences reached statistical significance at one or more observation points for pain, pain on motion, and tenderness.

CONCLUSION. PEMF hastherapeutic benefit in painful OA of the knee or cervical spine.

Trock D. et.al. Department of Medicine, Danbury Hospital,CT. J. of Rheumatology