Efficacy of Pulsed Electromagnetic Field Therapy as an Adjunct to Meloxicam and Exercise in Grade II and III Knee Osteoarthritis: A Randomized, Single-Blind Clinical Trial

Background: Osteoarthritis (OA) represents the most common form of arthritis, particularly among older adults, with knee osteoarthritis (KOA) being a major contributor to pain and disability. Exercise therapy is a core non-pharmacological intervention for managing OA, with proven benefits for pain relief and physical function. Clinical guidelines, such as those issued by European League Against Rheumatism (EULAR) and American College of Rheumatology (ACR), recommend strengthening, aerobic, and flexibility exercises for symptom control. Pulsed electromagnetic field (PEMF) therapy is a non-invasive modality with potential regenerative and anti-inflammatory effects. Objectives: This study aimed to evaluate the additional benefit of PEMF therapy when combined with meloxicam and structured exercise in participants with grade II and III KOA. Methods: In this single-blind randomized controlled trial, 60 participants with grade II-III KOA were recruited using convenience sampling. The required sample size was calculated a priori using the formula for comparing two independent means, based on a minimal clinically important difference (MCID) of 1.5 points on the Visual Analogue Scale (VAS), a standard deviation (SD) of 2.0, α = 0.05, and 80% power, yielding 27 participants per group. Considering a 10% anticipated dropout, 30 participants were assigned to each group. Randomization was performed using a computer-generated sequence, and allocation concealment was ensured through sealed opaque envelopes. The intervention group received PEMF therapy (75 Hz, 50 Gauss, 30 min/session, 3 times/week, 8 sessions), meloxicam (15 mg/day), and exercise, while the control group received sham PEMF plus the same standard care. Primary outcomes were pain (VAS) and function [Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)], assessed at baseline, post-treatment, 6 weeks, and 3 months. Results: All 60 participants completed the trial with no losses or exclusions. At 3 months, the intervention group demonstrated significantly greater pain reduction [VAS: From 9.13 ± 1.38 to 2.60 ± 1.73; Δ = -6.53, 95% confidence intervals (CI): -7.11 to -5.95; P < 0.001] than the control group (VAS: From 9.33 ± 0.88 to 8.20 ± 1.90). Similarly, WOMAC total scores improved more in the intervention group (from 79.93 ± 13.23 to 20.80 ± 9.76; Δ = -59.13, 95% CI: -63.9 to -54.4; P < 0.001). Effect sizes were large for both pain (η2 = 0.821) and function (η2 = 0.829). Conclusions: The PEMF therapy substantially enhances pain relief and physical function in participants with KOA, with no reported side effects. These findings support its use as a non-invasive adjunct treatment. Further studies with longer follow-up periods are warranted.