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Evaluation of photobiomodulation for modulating peripheral inflammation via the lumbosacral medullary region
Geovanna Rayssa Travessini1, Bianca Villanova1, Bruna Fernanda Rempel de Alcantara1
1Physical Therapy, Universidade Estadual do Oeste do Paraná, Cascavel, Paraná, Brazil.
Objectives:
The objective of this study was to evaluate whether PBM application at the nerve root emergence region could mitigate the deleterious effects of peripheral inflammation on the knee joint in Wistar rats.
Methods:
Eighteen Wistar rats were divided into three groups: Control (intra-articular saline injection only), Arthritis (experimental arthritis model without treatment), and PBM + Arthritis (arthritis model treated with PBM - 660 nm, 20 J/cm2). Treatment began 24 h after intra-articular arthritis induction and continued for three consecutive days. Animals in the arthritis groups were sensitized with two injections of Mycobacterium butyricum (CFA), while the control group received saline solution. The nociceptive threshold was assessed using a digital analgesimeter, and joint edema was measured with a caliper. After euthanasia, the right knee joints were collected, sectioned at 7 μm, and stained with hematoxylin and eosin. Histomorphometric and histomorphological analyses of the synovial membrane and articular cartilage of the femur and tibia were performed.
Results:
A reduction in nociceptive threshold and an increase in joint diameter were observed in the injured and treated groups. However, the PBM + Arthritis group showed pro-repair morphological characteristics in the joint tissue.
Conclusions:
PBM treatment applied distant from the injured knee promoted improvements in joint morphology; however, it did not significantly affect edema or nociception.
