Interferential current and photobiomodulation in knee osteoarthritis: A randomized, placebo-controlled, double-blind clinical trial.

OBJECTIVES: To evaluate the effects of interferential current and photobiomodulation in patients with knee osteoarthritis. DESIGN: A randomized, placebo-controlled, double-blind clinical trial. SETTING: Physiotherapy Clinic of City University of São Paulo. SUBJECTS: A total of 184 patients with knee osteoarthritis were recruited and, of these, 168 were included and randomized into four groups with 42 each: interferential current, photobiomodulation, interferential current plus photobiomodulation or placebo groups. One hundred and sixty-four patients completed the study. INTERVENTION: Patients received 12 sessions (three times a week) of treatment: 30 minutes of interferential current (active or placebo) followed by photobiomodulation (active or placebo). MAIN MEASURES: Primary outcome: pain intensity at rest and during movement (numeric rating scale) after 12 sessions. Secondary outcomes: functional capacity (Timed Up & Go and Sit and Lift tests and Lequesne and WOMAC questionnaires), pressure pain threshold, conditioned pain modulation, and muscle strength production (isokinetic evaluation). Patients were assessed at baseline, after 12 sessions, and three and six months after the end of the treatment. RESULTS: Interferential current plus photobiomodulation reduced pain intensity at rest and during movement compared to placebo and interferential current at all time points (P < 0.05). Photobiomodulation reduced pain intensity at rest compared to placebo at all time points (P < 0.05) and compared to interferential current at six months follow-up (P < 0.05). Photobiomodulation reduced pain intensity during movement compared to placebo at six months follow-up (P < 0.05). CONCLUSION: Interferential current plus photobiomodulation or isolated photobiomodulation improve pain intensity in knee osteoarthritis.

Low-level laser therapy and interferential current in patients with knee osteoarthritis: a randomized controlled trial protocol.

The aim of this study is to investigate the effects of low-level laser therapy and interferential current (IFC) on pain intensity, central sensitization, muscle strength and functional capacity in patients with knee osteoarthritis. Participants will be patients aged between 50 and 80 years, with knee osteoarthritis, pain intensity ranging from 3 to 8 points (0-10 scale), Lequesne Algofunctional Index ranging from 5 to 15 points, and Kellgren & Lawrence grade ≥2. A total of 168 patients will be randomly allocated into four groups as follows: active IFC + laser sham (G1), IFC sham + active laser (G2), active IFC + laser (G3) and IFC + laser sham (G4). Evaluators will be blinded to group allocation. Primary outcomes will be pain at rest and during movement measured with the visual analog pain scale. Clinical Trials Registry (NCT02898025. Registered on 20 April 2016).