A 3-month, randomized, double-blind, placebo-controlled study to evaluate the safety and efficacy of a highly optimized, capacitively coupled, pulsed electrical stimulator in patients with osteoarthritis of the knee

Objective: To investigate the efficacy and safety of a capacitively coupled, pulsed electrical stimulation device in treating knee osteoarthritis (OA). Design: Fifty-eight outpatients with moderate to severe OA of the knee entered a 3-month, double-blind, placebo-controlled trial, using either an active or placebo device at home for 6 to 14 h/day. Outcome measures included a patient global evaluation, a patient report of knee pain severity, and the Western Ontario and McMaster Universities (WOMAC) questionnaire. Results: Active treatment provided superior outcomes between baseline and 3-month follow-up measurements: 50.6% greater improvement than placebo in patient global (P= 0.03), 31.2% in patient pain (P= 0.04), 25.1% in WOMAC stiffness (P 0.03), 29.5% in WOMAC function (P= 0.01), 19.9% in WOMAC pain (P= 0.11), and 27% in total WOMAC (P= 0.01). The percent of patients who improved by more than 50% was 38.5 active vs 5.3 placebo in patient global (P= 0.01), 43.6 vs 15.8 in patient pain (P= 0.04), 38.5 vs 10.5 in WOMAC pain (P= 0.03), 28.2 vs 5.3 in WOMAC stiffness (P= 0.08), 23.1 vs 5.3 in WOMAC function (P= 0.14), and 23.1 vs 5.3 in total WOMAC (P= 0.14). Twenty-one percent of placebo and 18% of actively treated patients developed a transient rash at the electrode sites. No other adverse device effects were reported. Conclusion: A highly optimized, capacitively coupled, pulsed electrical stimulus device significantly improved symptoms and function in knee OA without causing any serious side effects. (c) 2007 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.