Light Therapy on Pain and Synovitis

NCT07057063 | Recruiting

• 1 other identifier: HSEARS20230214003 PolyU
• Study Type: interventional
• Target: 80
• Locations: 2 countries
• Sites: 2

Brief Summary

Background: Knee pain is a common complaint among middle-aged and older adults, often leading to reduced mobility and diminished quality of life. Synovitis is a major underlying cause, present in up to 80% of individuals with moderate knee pain. While light therapy has shown anti-inflammatory and analgesic effects in preclinical studies, our prior animal experiments revealed that light therapy at 810 nm significantly alleviated inflammation and pain-like behaviors. These findings suggest a potential wavelength-specific therapeutic effects. However, it remains unclear whether such effects can be replicated in humans. This study aims to evaluate the efficacy of 810 nm light therapy, compared to sham treatment, in reducing knee pain and synovitis in patients with chronic knee pain and knee synovitis. Methods/design: This is a randomized, placebo-controlled clinical trial involving 90 participants with chronic knee pain and ultrasound-detected synovitis. Participants will be randomized into two groups to receive 810 nm light therapy, or sham therapy, delivered twice weekly over five weeks. Primary outcomes include knee pain assessed by the Visual Analogue Scale (VAS) and synovitis assessed by ultrasound. Secondary outcomes include the Knee injury and Osteoarthritis Outcome Score (KOOS), the 30-second chair stand test, and the 40-meter fast-paced walk test. Outcome assessments will be performed at baseline, post-intervention (week 5), and at 1 month and 6 months after treatment completion. Linear mixed-effects models will be used to compare outcome changes between groups. Discussion: This trial will assess whether 810 nm light therapy provides clinically meaningful benefits for reducing knee pain and synovitis in humans, building on promising preclinical findings. Results from this study may support the use of near-infrared light as a safe, non-invasive, and effective intervention for synovitis-related knee pain.

Conditions

Knee Pain Chronic; Synovitis of Knee; Light Therapy

Keywords

Light therapy; Photobiomodulation; Chronic knee pain; Synovitis; Randomized controlled trial; Non-pharmacological intervention; physical therapy

Outcome Measures

Primary Outcomes (2)

• Knee pain (Visual Analogue Scale, VAS)

  Knee pain severity will be assessed using a 100-mm Visual Analogue Scale (VAS), based on average pain over the past week.

  Baseline, Week 5, 1-month follow-up, 6-month follow-up

• Knee synovitis grade (Ultrasound assessment)

  Knee ultrasound will be performed by an ultrasound physician with over 8 years of experience, following the published protocol (Bruyn GAW, Naredo E, Damjanov N, et al (2016) An OMERACT reliability exercise of inflammatory and structural abnormalities in patients with knee osteoarthritis using ultrasound assessment. Ann Rheum Dis 75:842-846. https://doi.org/10.1136/ann). The items measured included the maximal score for synovitis obtained at the suprapatellar or parapatellar recesses, with a range of 0-3. Grade 0 indicates no synovitis; Grade 1 represents minimal distension of the recess by abnormal internal hypoechoic or anechoic material (relative to subdermal fat tissue); Grade 2 signifies moderate distension or enlargement of the recess by abnormal internal hypoechoic or anechoic material with a flat or concave superficial limit; and Grade 3 denotes severe distension or enlargement of the recess by abnormal internal hypoechoic or anechoic material with a bulging superficial limit.

  Baseline, Week 5, 1-month follow-up, 6-month follow-up

Secondary Outcomes (4)

• Knee Injury and Osteoarthritis Score (KOOS)

  Baseline, Week 5, 1-month follow-up, 6-month follow-up

• Lower limb function (30-second chair stand test)

  Baseline, Week 5, 1-month follow-up, 6-month follow-up

• Walking speed (40-meter fast-paced walk test)

  Baseline, Week 5, 1-month follow-up, 6-month follow-up

• Adverse events monitoring for light therapy

  Throughout the intervention period and at all follow-up visits (up to 6 months)

Study Arms (2)

810 nm Light Therapy Group

EXPERIMENTAL

Participants receive 810 nm light therapy using a wearable device, twice per week for 5 weeks.

Device: 810 nm Light Therapy

Sham Therapy Group

PLACEBO COMPARATOR

Participants receive sham therapy with the same device that emits no therapeutic light, twice per week for 5 weeks.

Device: Sham Light Therapy

Interventions

810 nm Light Therapy DEVICE

Light therapy at 810 nm, 39 J/cm², delivered via wearable device.

810 nm Light Therapy Group

Sham Light Therapy DEVICE

Identical device, no light output, delivered via wearable device.

Sham Therapy Group

Eligibility Criteria

• Age: 40 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Participants aged between 40 and 80 years
• Able to provide written informed consent
• Have experienced knee pain that persists or recurs for more than 3 months
• A knee pain score of at least 30 mm on the 100-mm Visual Analogue Scale (VAS) during the past week
• Ultrasound-measured knee synovitis ≥1
• Presence of knee OA according to criteria established by the American College of Rheumatology

You may not qualify if:

• Anticipated need for knee surgery within the next one year
• Previous or planned knee replacement within the next one year
• Knee surgery or other physical therapy in the previous 3 months
• Use of intra-articular, intra-muscular, or oral corticosteroids in previous 4 weeks
• Malignant tumors or other life-threatening diseases
• Severe mental disorders, including but not limited to schizophrenia, bipolar disorder, or major depressive disorder, that may interfere with the participant's ability to comply with the study protocol or provide informed consent

Sponsors & Collaborators

• The Hong Kong Polytechnic University: lead

Study Sites (2)

Buji Community Service Center, Longgang District

Shenzhen, China

RECRUITING

The Hong Kong Polytechnic University

Hong Kong, Hong Kong

NOT YET RECRUITING

Related Publications (1)

• 1. Duong V, Oo WM, Ding C, et al (2023) Evaluation and Treatment of Knee Pain: A Review. Jama 330:1568-1580. https://doi.org/10.1001/jama.2023.19675 2. Baker K, Grainger A, Niu J, et al (2010) Relation of synovitis to knee pain using contrast-enhanced MRIs. Ann Rheum Dis 69:1779-83. https://doi.org/10.1136/ard.2009.121426 3. Blom AB, van Lent PLEM, Holthuysen AEM, et al (2004) Synovial lining macrophages mediate osteophyte formation during experimental osteoarthritis. Osteoarthr Cartil 12:627-35. https://doi.org/10.1016/j.joca.2004.03.003 4. Mathiessen A, Conaghan PG (2017) Synovitis in osteoarthritis: Current understanding with therapeutic implications. Arthritis Res Ther 19:1-9. https://doi.org/10.1186/s13075-017-1229-9 5. Zhu Z, Li J, Ruan G, et al (2018) Investigational drugs for the treatment of osteoarthritis, an update on recent developments. Expert Opin Investig Drugs 27:881-900. https://doi.org/10.1080/13543784.2018.1539075 6. Mussttaf RA, Jenkins DFL, Jha AN (2019) Assessing the impact of low level laser therapy (LLLT) on biological systems: a review. Int J Radiat Biol 95:120-143. https://doi.org/10.1080/09553002.2019.1524944 7. de Freitas LF, Hamblin MR (2016) Proposed Mechanisms of Photobiomodulation or Low-Level Light Therapy. IEEE J Sel Top Quantum Electron 22:. https://doi.org/10.1109/JSTQE.2016.2561201 8. de Oliveira VLC, Silva JA, Serra AJ, et al (2017) Photobiomodulation therapy in the modulation of inflammatory mediators and bradykinin receptors in an experimental model of acute osteoarthritis. Lasers Med Sci 32:87-94. https://doi.org/10.1007/s10103-016-2089-2 9. Hagiwara S, Iwasaka H, Okuda K, Noguchi T (2007) GaAlAs (830 nm) low-level laser enhances peripheral endogenous opioid analgesia in rats. Lasers Surg Med 39:797-802. https://doi.org/10.1002/lsm.20583 10. dos Santos SA, dos Santos Vieira MA, Simões MCB, et al (2017) Photobiomodulation therapy associated with treadmill training in the oxidative stress in a collagen-induced arthrit

  BACKGROUND

MeSH Terms

Conditions

Synovitis

Interventions

Phototherapy

Condition Hierarchy (Ancestors)

Joint Diseases; Musculoskeletal Diseases

Intervention Hierarchy (Ancestors)

Therapeutics

Central Study Contacts

Tianxiang Fan, PhD candidate

CONTACT

+85268411557; tianxiang.fan@connect.polyu.hk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Allocation will be not revealed to the participants and ultrasound assessors until the completion of the final data analyses.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Peter Hung Professor in Pain Management, Assoc. Head(RS), ADoRISports & Professor

Model Details: randomized controlled trial

Study Record Dates

• First Submitted: June 25, 2025
• First Posted: July 9, 2025
• Study Start: July 13, 2025
• Primary Completion (Estimated): May 28, 2026
• Study Completion (Estimated): May 28, 2026
• Last Updated: November 26, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: De-identified individual participant data and supporting documents will be available beginning 6 months after publication of the primary results, and will be available for 5 years thereafter.
• Access Criteria: Data will be available to qualified researchers whose proposed use of the data has been approved by an independent review committee. Access will be provided after signing a data access agreement. Interested researchers should contact the Principal Investigator by email.

Locations

HK (1); CN (1)