Fotobiomodulação local e paravertebral na dessensibilização neurológica da dor crônica de joelhos em pacientes obesos: ensaio clínico duplo cego, randomizado

Abstract

Obesity is a global public health problem and is directly linked to loss of quality of life, complications and comorbidities. One of these is chronic pain, especially in the knees, which increases significantly disability, generating functional limitations in the basic activities of daily living. Photobiomodulation (PBM) has been studied and shown to be safe, with good efficacy for pain treatment being also well tolerated by patients. Thus, this study aimed to evaluate the use of PBM for the treatment of chronic knee pain in patients with grade 3 obesity, undergoing a pre-bariatric surgery rehabilitation program. This is a double-blind, randomized, superiority clinical trial. Participants undergoing treatment with the pre-bariatric surgery rehabilitation program indicated by the responsible care team, in addition to the recommended conventional pain treatment, were randomized into 2 groups: PBM and placebo PBM. The intervention studied was applied with the Therapy EC (DMC®) device on bilateral knees (4J/points and 4 anterior points) and on lumbar paravertebral points (3J/point in 10 points) related to the knee innervation roots, aiming at local improvement and neurological sensitization of chronic knee pain. The PBM and placebo PBM sessions occurred twice a week, associated to conventional treatment in both groups, totaling 24 sessions. All medications in use and interventions recommended by the healthcare team were maintained for all participants. The results obtained in the preliminary analysis of 20 participants, with the visual analogue scale for pain, showed statistical differences between the moments before and after treatment, with no difference between the groups. For all outcomes evaluated, SF-36, Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaires, algometry and walking test, there was an improvement in their domains before and after the intervention, with no difference between the 2 groups. These results suggest that PBM is not superior to placebo in patients performing a coordinated physical activity and that the studied population probably requires higher light doses of laser energy for knee analgesia with PBM, although this protocol follows the WALT recommendations for light doses. Despite this, the effect size of the use of this PBM protocol associated with conventional treatment necessary to obtain complete pain relief (VAS 0 after the intervention), compared to placebo PBM associated with conventional treatment, assessed with the Chi-Square Test, was 12%. These results should be confirmed in studies with larger samples, with protocols with a greater amount of energy than usual and in participants who have contraindications to the practice of physical exercise, which will probably have greater PBM effect sizes and clinical benefits than those evaluated in this study.