Effects of Low‐level Laser Therapy at Wavelengths of 660 and 808 nm in Experimental Model of Osteoarthritis

Abstract

The aim of the present study was to analyze the influence of low-level laser radiation at wavelengths of 660 and 808 nm in an experimental model of osteoarthritis (OA). The sample was composed of 36 male adult Wistar rats divided into three groups (G1, G2 and G3). For the induction of cartilage injury, three injections of 4% papain and 10 μL of a cysteine solution were performed at right knee of the hind leg. Two weeks after the last injection, group G1 was treated with InGaAlP (660 nm, 100 mW, 3.57 W cm(-2), 40 s) and G2 was treated with AsGaAl (808 nm, 100 mW, 3.57 W cm(-2), 40 s) both with energy of 4 J. There were significant differences in the type of squamous epithelium between days 7 and 14 in G2 (P < 0.05) and on day 14 between G1 and G2 (P < 0.05). Moreover, statistically significant differences were found in the formation of new blood vessels between G1 and G3 on days 7 and 21 as well as between G2 and G3 on day 21. The formation of fibrotic tissue was greater in G3 (P < 0.05). In conclusion, laser therapy, especially at a wavelength of 808 nm, stimulated angiogenesis and reduced the formation of fibrosis in an experimental model of OA.

Effect of Laser Therapy on Chronic Osteoarthritis of the Knee in Older Subjects

“…10 In addition, it has a positive effect on modulation of inflammation 13,14,42 and stimulation of angiogenesis as well as in the reduction of fibrosis formation. 15 Improvements of physical joint function outcomes usually occur as a consequence of pain intensity reduction, as pain reduction is usually primarily responsible for improvements in muscle function. 43 Application of exercise training programs for treatment of OA is proved to provide more efficiency in patient's care 29,34,44 The Ottawa Panel recommends application of active therapeutic exercises alone, or in combination with manual therapy, in management of patients with OA.…”

“…5 Recently, low-level laser therapy (LLLT) has been broadly used to control pain, 1,12 and it has been recommended for its anti-inflammatory effects 13,14 in addition to healing efficacy. 2,15 LLLT has been used in a wide range musculoskeletal disorders such as cervical spondylosis, epicondylitis, low-back pain, 16 and recently on knee OA. 12,17,18 However, some studies have not been able to identify significant clinical benefits in some painful musculoskeletal conditions.…”

Effect of Low-Level Laser Therapy in an Experimental Model of Osteoarthritis in Rats Evaluated Through Raman Spectroscopy

“…10 Alves et al 11 reported that laser therapy (780 nm) modulates inflammatory response both in the early and in the late progression stages of rheumatoid arthritis (RA). Da Rosa et al 12 observed the formation of new blood vessels in the laser-treated groups (660 nm) on the 7th day of treatment.…”

“…23 Traditionally, the composition of bone and cartilage is determined by standard histological methods. However, although much of the actual research work uses histological methods to show the effects of LLLT cartilage and subchondral bone destroyed by OA, 11,12 few studies employed Raman spectroscopy for this purpose. Abnormal molecular changes observed in the matrix of OA subchondral bone and proper cartilaginous matrix formation have been studied by means of Raman spectroscopy.…”

Analgesic Efficacy of Low Intensity Laser Therapy in a Monosodium Iodoacetate-induced Osteoarthritic Rat Model

“…Low-intensity laser therapy (LILT) has numerous clinical benefits such as improved tissue metabolism, pain reduction via reduce inflammation, blocked nerve sensitivity via the anagogic effect, and nerve regeneration at the tissue level [18][19][20] . Low-level laser photons can penetrate deep into the body through the skin, muscles, tendons, ligaments, nerves, and even bones, in order to pinpoint and target painful and damaged areas 21) .…”