Pulsed Electromagnetic Fields can Reduce Pain in the Short Term in Patients with Knee Osteoarthritis
/Summary of: Bagnato GL, Miceli G, Marino N, Sciortino D, Bagnato GF. Pulsed electromagnetic fields in knee osteoarthritis: a double blind, placebo-controlled, randomized clinical trial. Rheumatology (Oxford) 2016;55:755-762.
Question: Can daily treatment with pulsed electromagnetic fields decrease pain in patients with knee osteoarthritis? Design: A randomised, double-blind, placebo-controlled clinical trial. Setting: One Italian rheumatology outpatient clinic. Participants: People aged over 40 years with a diagnosis of primary osteoarthritis of the knee according to the American College of Rheumatology criteria; symptomatic disease for the last 6 months with persistent pain defined as a minimal mean score of 40 mm on a Visual Analogue Scale (VAS) despite receiving maximal tolerated doses of conventional medication. Randomisation allocated 33 patients to active treatment and 33 to placebo treatment. Interventions: Participants in the treatment group were given a pulsed electromagnetic fields wearable device, while those in the placebo group received a device with no electromagnetic properties. The devices that were used are commercially available and the placebo devices were identical to the active devices, including a light-emitting diode light showing operation. The devices were used 12 hours daily for 1 month. Outcome measures: A blinded assessor administered the outcome measures at 1 month (end of treatment): pain measured on a VAS (VAS-pain, 0 to 100); the
Western Ontario and McMaster Universities Osteoarthritis Index, subscale pain (WOMAC-pain); and the Medical Outcomes Study Short-Form 36 version-2 (SF-36) physical and mental component summary scores (0 to 100). Results: A total of 60 participants (91%) completed the assessment at 1 month. The mean difference was 13.6 units (95% CI 7.9 to 19.3) in VAS-pain and 5.6 units (95% CI 2.9 to 8.4) in WOMAC-pain, both favouring the active pulsed electromagnetic fields group. There were minor differences in favour of the pulsed electromagnetic fields group in the SF-36 physical health (mean difference 2.7 units, 95% CI 0.3 to 5.2) and the SF-36 mental health (mean difference 0.5 units, 95% CI –1.5 to 2.6). Conclusion: In patients with painful knee osteoarthritis, pulsed electromagnetic fields decreased pain, but had little impact on health-related quality of life. Provenance: Invited. Not peer reviewed.
Ka ̊ re Birger Hagena and Margreth Grotleba National Advisory Unit on Rehabilitation in Rheumatology, Department of Rheumatology, Diakonhjemmet Hospital b Oslo and Akershus University College of Applied Sciences, Department of Physiotherapy, Oslo, Norway