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

Abstract

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.

Effectiveness of interferential current therapy in patients with knee osteoarthritis: a systematic review and meta-analysis of randomized controlled trials

“…After reviewing the remaining articles’ titles and full texts, 67 articles were identified as irrelevant articles and were excluded. Among the remaining 33 articles, 10 RCTs met the eligibility criteria 16 – 25 , and nine RCTs 17 – 25 were pooled into our meta-analysis; they were all parallel studies. A detailed flowchart of the study selection process is presented in Fig.…”

“…Nine trials 17 – 25 reported improvement of pain as a main outcome by using the visual analog scale (VAS) or the numeric rating scale (NRS) 26 . For the assessment of functional capacity, seven trials 18 , 20 – 25 used the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), which assesses the domains of pain, joint stiffness, and physical activity 27 .…”

“…Three trials assessed mobility function by measuring the time taken to complete walk tests 22 , 23 , 25 . Three trials reported stiffness by using the VAS or WOMAC (specifically the stiffness domain) 19 , 23 , 24 .…”

“…This assessment was reviewed by two reviewers independently. The studies obtained scores of 4–9 points for overall quality; as per the assessment, six studies 16 – 18 , 21 – 23 were good-quality studies, two 19 , 20 were fair-quality studies, and the two most recent studies 24 , 25 were excellent-quality studies.…”

“…Our results indicated that the IFC groups exhibited significant improvement for both short- and long-term pain relative to the control groups. For short-term pain, all nine RCTs were included, and heterogeneity across studies was moderate (SMD = − 0.64; 95% CI − 1.04 to − 0.25; n = 467; I 2 = 73%) 17 – 25 . For long-term pain, three studies were included, and heterogeneity across studies was low (SMD = − 0.36; 95% CI − 0.60 to − 0.11; n = 258; I 2 = 1%) 20 , 22 , 25 .…”