RESUMEN
Low-level laser therapy [LLLT] is thought to have analgesic and biomodulatory effects. Our objective was to assess the pain-relieving effect of LLLT and possible changes in joint stiffness and disability of patients with knee osteoarthritis [KOA] and compare it to the more commonly used modality; therapeutic ultrasound[US]. 37 patients with mild or moderate KOA were randomized to receive either LLLT, placebo LLLT or US. All patients received a common treatment including acetaminophen [up to 2gr/d] and medical advices for lifestyle modification and exercise. Treatments were delivered 5 times a week over a period of 2 weeks. Active laser group was treated with a diode laser [wavelength 880 nm, continuous wave, power 50 mW] at a dose of 6 J/point [24 J/knee]. The placebo control group was treated with an ineffective probe [power 0 mW] of the same appearance. The third group received pulsed ultrasound with an intensity of 1.5-2 w/cm2, and for 5 minutes per knee. Visual Analogue Scale [VAS] and Western Ontario MacMaster [WOMAC] questionnaires were used for data gathering before,1 and 3 months after completing the therapy. Pain reduced in all 3 groups but laser was superior in comparison. Stiffness improved 1 mo after therapy in the laser group but not in the others. Disability decreased in both laser and US groups [more significantly in the laser group] but not in the placebo group. Our results show that LLLT reduces pain, joint stiffness and disability in KOA and is superior to placebo and US