Photobiomodulation in Chronic Knee Pain in Patients Who Are in PreRehabilitation for Bariatric Surgery

Last updated: June 2, 2025
Sponsor: University of Nove de Julho
Overall Status: Active - Recruiting

Phase

2/3

Condition

Chronic Musculoskeletal Pain

Treatment

Standard Physiotherapy Tretament

Photobiomodulation

Photobiomodulation Placebo

Clinical Study ID

NCT05816798
PhotobioKneepain
  • Ages 18-70
  • All Genders

Study Summary

Chronic pain is a global public health problem, which intensifies even more in the obese population, reaching about 33% of these patients. Among the topography, chronic knee pain affects 80%, constituting an important cause of disability and decreased quality of life. In addition, in grade 3 obesity, also called morbid obesity, in which bariatric surgery is already indicated, knee pain makes it difficult or prevents participation in the pre-habilitation program that includes physical therapy through therapeutic exercises with the aim of reducing postoperative complications. In this sense, a double-blind, randomized, placebo-controlled clinical trial will be conducted with the objective of evaluating the effect of photobiomodulation (PBM) on pain and functionality of obese patients with chronic knee pain who are in a prehabilitation program for bariatric surgery, discussing its role as an analgesic therapy and modifier of peripheral and central sensitization mechanisms of the pain pathway. PBM is a safe treatment option, with no undesirable effects and low cost. The primary outcomes will be pain intensity, through visual analogue scale, and Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire, validated version for Portuguese - Brazil. Secondary outcomes will be pressure pain threshold and rolling pinch maneuver measured by digital algometer. Other exploratory outcomes will be 6-minute walk test, knee range of motion, SF-36 quality of life questionnaire. There will be 2 groups: an intervention group (photobiomodulation associated with standard physiotherapy treatment) and another placebo group (device turned off associated with the same standard physiotherapy treatment). The application sites will be knees and lumbar paravertebral 2 times a week for 12 weeks. The dosimetric standards will be 4J/point in the knees and 3J/point in the lumbar. The results obtained will be statistically analyzed and later published in a scientific journal.

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • Obese patients with indication for bariatric surgery performed in routine follow-upat the Gastric Surgery Outpatient Clinic of HC-UFG;

  • Patients with chronic pain (> 3 months) in the knees bilaterally. Patients will beasked in the initial evaluation if they feel pain located in the topography of theknees that has been compromising their functionality both in daily activities and atwork, and that lasts for more than or equal to 3 months. This pain may be reportedas continuous or intermittent;

  • Sign the Informed Consent Term approved by the HC-UFG Ethics Committee.

Exclusion

Exclusion Criteria:

  • Loss of follow-up in the outpatient clinic of origin and in the Physiotherapysector, even though the use of laser therapy was maintained according to thestudy protocol;

  • Any reported adverse effects from the use of FBM reported;

  • Patients in whom there are changes in the medications being used for chronic painduring the study protocol will be excluded from this study. Minimal changes in thedosages of medications already in use can be tolerated, as long as there are nochanges in the type of medication, but only in the prescribed dose. Thesemodifications throughout the study, if they occur, will be described.

  • Death

  • Withdrawal of the informed consent by the participant

  • If the patient, for any reason, is excluded from the indication of bariatric surgery

  • Emergence during the study of any of the non-inclusion criteria, like: .

  • Patients with other rheumatologic diseases and/or systemic inflammatory diseases (rheumatoid arthritis, Reiter's arthritis, ankylosing spondylitis, generalizedpolyarthritis) or previous musculoskeletal diseases in the knees;

  • Clinical manifestations or complaints of knee arthralgia related to diseases otherthan obesity.

  • Previous use in the last 90 days of treatment with the use of Phototherapy for thesame or another indication;

  • Clinical signs of neuropathy, including radiculopathies and peripheral nerveinjuries;

  • Pain in the lower limb, originating from the lumbar spine (lombosciatalgia)

  • Use of corticosteroids at an immunosuppressive dose (20mg daily of prednisone orequivalent for at least 14 days);

  • Infection or tumor at the site of therapy application;

  • Current chronic infections such as tuberculosis or chronic hepatitis treated or not.

  • Blood clotting disorders (including thrombosis) at the application site.

  • Diagnosis of fibromyalgia;

  • Serious psychiatric disorders that require psychiatric care;

  • Systemic injections and/or joint injections of corticosteroids or hyaluronic acidduring the last 48 hours prior to the initial assessment of the study;

  • Psychoaffective disorder that compromises adherence to treatment;

  • Any history of sensitivity to light or phototherapies.

Study Design

Total Participants: 62
Treatment Group(s): 3
Primary Treatment: Standard Physiotherapy Tretament
Phase: 2/3
Study Start date:
July 28, 2023
Estimated Completion Date:
February 28, 2026

Study Description

Chronic pain is a global public health problem, which intensifies even more in the obese population, reaching about 33% of these patients. Among the topography, chronic knee pain affects 80%, constituting an important cause of disability and decreased quality of life. In addition, in grade 3 obesity, also called morbid obesity, in which bariatric surgery is already indicated, knee pain makes it difficult or prevents participation in the pre-habilitation program that includes physical therapy through therapeutic exercises with the aim of reducing postoperative complications. In this sense, a double-blind, randomized, placebo-controlled clinical trial will be conducted with the objective of evaluating the effect of photobiomodulation (PBM) on pain and functionality of obese patients with chronic knee pain who are in a prehabilitation program for bariatric surgery, discussing its role as an analgesic therapy and modifier of peripheral and central sensitization mechanisms of the pain pathway. PBM is a safe treatment option, with no undesirable effects and low cost. The primary outcomes will be pain intensity, through visual analogue scale, and Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire, validated version for Portuguese - Brazil. Secondary outcomes will be pressure pain threshold and rolling pinch maneuver measured by digital algometer. Other exploratory outcomes will be 6-minute walk test, knee range of motion, SF-36 quality of life questionnaire. There will be 2 groups: an intervention group (photobiomodulation using Therapy EC-DMC device associated with standard physiotherapy treatment) and another placebo group (device turned off associated with the same standard physiotherapy treatment). The application sites will be knees (4 anatomically described points) and lumbar paravertebral (levels L3 to S2 bilateral - 10 points, being 05 points each side) 2 times a week for 12 weeks. The dosimetric standards will be 4J/point (40 seconds) in the knees and 3J/point (30 seconds) in the lumbar. The results obtained will be statistically analyzed using SPSS 28.0 software, and later published in a scientific journal.

Connect with a study center

  • Gastric Outpatient Clinic of HC-UFG

    Goiânia, Goiás 74605-050
    Brazil

    Active - Recruiting

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