Effect Of Photobiomodulation (Low-Level Laser Therapy) In Patients With Knee Osteoarthritis: A Randomized Controlled Trial

Abstract

This study aimed to evaluate the effects of photobiomodulation (low-level laser therapy) on patients with symptomatic knee osteoarthritis through a double-blind, randomized clinical trial conducted in accordance with the CONSORT guidelines for non-pharmacological interventions. The initial sample included 73 participants of both sexes; however, 8 individuals withdrew, leaving 65 for final analysis. Participants were randomly assigned to one of three groups: photobiomodulation (PBM), sham (placebo), or control (no intervention). In the PBM group, 83% were female and 17% male; the sham and control groups had 85% female and 15% male. The PBM group received treatment following WALT recommendations, using a 790 nm wavelength laser delivering 4 J per point, applied to nine specific areas of the knee. Significant reductions in pain (p < 0.05) were observed in the PBM group after treatment, compared to both the placebo and control groups. WOMAC scores showed significant improvements in pain, stiffness, and functional limitations within the PBM group (pre- vs. post-treatment) (p < 0.05), while no significant changes were found in the sham or control groups (p > 0.05). These findings demonstrate that photobiomodulation (790 nm, 120 mW, 4 J/point) is effective in reducing pain (VAS), improving daily function and quality of life (KOOS), and enhancing clinical outcomes in patients with knee osteoarthritis, specifically when compared to sham and control conditions.

Keywords: Knee osteoarthritis; Low-Level Laser Therapy; Pain; Functionality; Photobiomodulation.