Light Therapy on Pain and Synovitis

NCT ID: NCT07057063

Last Updated: 2025-11-26

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 80 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-07-13
• Study Completion Date: 2026-05-28

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

Sham Therapy Group

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

Group Type: PLACEBO_COMPARATOR

Sham Light Therapy

Intervention Type: DEVICE

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

810 nm Light Therapy Group

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

Group Type: EXPERIMENTAL

810 nm Light Therapy

Intervention Type: DEVICE

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

Interventions

810 nm Light Therapy

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

Intervention Type: DEVICE

Sham Light Therapy

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

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• 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

Exclusion Criteria

• 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

• Minimum Eligible Age: 40 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

The Hong Kong Polytechnic University

OTHER

Sponsor Role: lead

Responsible Party

FU Siu Ngor

Peter Hung Professor in Pain Management, Assoc. Head(RS), ADoRISports & Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Buji Community Service Center, Longgang District

Shenzhen, , China

Site Status: RECRUITING

The Hong Kong Polytechnic University

Hong Kong, , Hong Kong

Site Status: NOT_YET_RECRUITING

Countries

China; Hong Kong

Central Contacts

Tianxiang Fan, PhD candidate

Role: CONTACT

tianxiang.fan@connect.polyu.hk

+85268411557

Facility Contacts

Tianxiang Fan

Role: primary

tianxiang.fan@connect.polyu.hk

86 15750867202

Tianxiang Fan

Role: primary

tianxiang.fan@connect.polyu.hk

852 68411557

References

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

Reference Type: BACKGROUND

Other Identifiers

HSEARS20230214003 PolyU

Identifier Type: -

Identifier Source: org_study_id