Low level laser therapy investigated as treatment for arthritis pain

By Dava Stewart

Arthritis is, broadly, a disorder that includes joint inflammation, and there are different types of this complex disease.¹ Approximately 350 million people worldwide suffer from arthritis, and around 40 million of them live in the United States.² Given these numbers, there is a high likelihood that in any given chiropractic office, some percentage of the patients have arthritis.

Low level laser therapy (LLLT) has been investigated as a treatment for a great number of injuries, illnesses, and conditions, including arthritis. Many researchers agree that LLLT is an effective treatment for relieving pain and for reducing inflammation when optimal protocols are used.³

A metaanalysis completed in 2000 and published in The Journal of Rheumatology considered trials for both osteoarthritis (OA) and rheumatoid arthritis (RA). Their conclusion was as follows:

“LLLT should be considered for short term relief of pain and morning stiffness in RA, particularly since it has few side effects. For OA, the results are conflicting in different studies and may depend on the method of application and other features of the LLLT. Clinicians and researchers should consistently report the characteristics of the LLLT device and the application techniques. New trials on LLLT should make use of standardized, validated outcomes. Despite some positive findings, this metaanalysis lacked data on how effectiveness of LLLT is affected by 4 factors: wavelength, treatment duration of LLLT, dosage, and site of application over nerves instead of joints. There is a need to investigate the effects of these factors on effectiveness of LLLT for RA and OA in randomized controlled clinical trials.” ⁴

Another study, published in 2005, researched LLLT in the treatment of OA in the hand and concluded:

“LLLT is no better than placebo at reducing pain, morning stiffness, or improving functional status for OA-hand patients.” ⁵

With such conflicting results in numerous studies, scientists continued to investigate. In 2012, a group of researchers studied how various arthritis markers were affected by treatment with LLLT at different intensities. They concluded:

“Knee arthritis is a complex problem with a number of underlying cellular, biochemical, and physical causes. Leukocyte infiltration to the joint is a hallmark of arthritis. In our study, laser irradiation was significantly effective in reducing the total number of leukocytes as well as neutrophils in joint cavity. This fact was corroborated by the inhibition of myeloperoxidase activity that represents a chemical marker of neutrophil infiltration.” ⁶

And just this year, a study published in Lasers in Medical Science found “that LLLT is effective in reducing pain in knee osteoarthritis.”⁷

LLLT has been studied as a treatment for arthritis for more than 20 years, and the results continue to be conflicted. The protocols used during LLLT—the intensity of the laser, the length of time it is used, the pulsation—appear to be all-important. One thing is clear: LLLT does no harm, and in many of the trials and studies, it has been shown to be beneficial. Laser manufacturers and vendors include recommended protocols for a wide variety of uses. DCs should follow those protocols and be aware that research is on going.

References

¹National Center for Chronic Disease Prevention and Health Promotion. “Arthritis.” CDC.gov. http://www.cdc.gov/arthritis/basics/faqs.htm. Updated March 2014. Accessed November 2014.

²MedicineNet. “National Arthritis Month.” MedicineNet.com. http://www.medicinenet.com/script/main/art.asp?articlekey=23220. Updated May 2003. Accessed November 2014.

³Castano A, et al. “Low-level laser therapy for zymosan-induced arthritis in rats: Importance of illumination time.” Lasers in Surgery and Medicine. 2007:39(6);543-550.

⁴Brosseau L, et al. “Low level laser therapy for osteoarthritis and rheumatoid arthritis: a metaanalysis.” The Journal of Rheumatology. 2000:27(8);1961-1969.

⁵Brosseau L, et al. “Randomized controlled trial on low level laser therapy (LLLT) in the treatment of osteoarthritis (OA) of the hand.” Lasers in Surgery and Medicine. 2005:36(3);210-219.

⁶Pallotta R, et al. “Infrared (810-nm) low-level laser therapy on rat experimental knee inflammation.” Lasers in Medical Science. 2012:27(1);71-78.

⁷Soleimanpour H, et al. “The effect of low-level laser therapy on knee osteoarthritis: prospective, descriptive study.” Lasers in Medical Science. 2014:29(5);1695-1700.