Editor’s note: This editorial concludes a two-part series on the use of low-level laser therapy for musculoskeletal pain. The first article appeared in the September issue of AAOS Now.

The Food and Drug Administration (FDA) cleared the Erchonia FX 635, a low-level laser therapy (LLLT) device, for “whole body” pain in July. Part one of this series explored the history and theoretical mechanism of action for such devices. This article explores the available literature regarding LLLT for orthopaedic applications.

The literature

As a spine surgeon, I started by examining Erchonia’s data for low back pain (LBP). In introducing its study, the manufacturer stated, “Most LBP stems from benign musculoskeletal problems, referred to as nonspecific LBP, which is the etiology being evaluated in this study. It is caused by lumbar sprain or strain, a stretch injury to the ligaments, tendons, and/or muscles of the low back.”

The study’s principal investigators, Trevor Berry, DC, and Mark B. Burdorf, DC, DACNB, randomized 62 adults to receive laser or placebo from 2012 to 2015. Important exclusions included some structural spine problems (e.g., disk herniations and compression fractures) and concomitant or recent use of certain medications (e.g., muscle relaxers).

The tested device, “the Erchonia® MLS, contains 10 independent diodes, each emitting 17 milliwatts, 635 nanometers (nm) of red laser light.” The study applied the laser light to the lower back and hips for 15 minutes twice a week for three weeks. The primary outcome was the percentage of patients reporting at least 35 percent reduction in pain according to a visual analog scale (VAS). Statistically significant improvements were noted in the laser group for the primary outcome and secondary outcomes, including satisfaction and overall change in VAS. No adverse events were noted in either cohort.

The company’s statement following the FDA clearance compared its own results with those of the SPACE trial (which did not include lasers). Erchonia reported an overall 49 percent reduction in pain without adjunctive treatment, which the company noted is favorable to the 20 percent pain reduction observed with opioids. On the other hand, the study populations were far from comparable.

Before the recent FDA approval for whole-body pain, hundreds of studies had examined LLLT in other musculoskeletal applications, with variable results. Just as disparate as the results of the individual trials, the systematic reviews also reached different conclusions. Although the last Cochrane Review for LLLT for chronic LBP was published in 2008, more recent systematic reviews address its use in hair loss (potentially effective), carpal tunnel syndrome, rheumatoid arthritis, root canal and periodontitis, tuberculosis, and more.

For example, a recent trial that included 18 patients compared VAS pain levels and serum tumor necrosis factor (TNF)-alpha and interleukin (IL)-8 levels in patients receiving photobiomodulation (PBM) versus placebo. Significant decreases in pain, TNF-alpha, and IL-8 were noted in the PBM group.

In 2017, Kibar et al., published the results of a randomized, double-blind, sham-controlled study that assessed laser acupuncture in patients with impingement syndrome. After 15 treatments at 11 acupuncture points, the group receiving LLLT had less pain, greater forward elevation, and improved scores on a shoulder disability index compared to the sham laser group.

A recent meta-analysis of LLLT in fibromyalgia (with low to moderate evidence) concluded, “LLLT is an effective, safe, and well-tolerated treatment for fibromyalgia.” Similarly, another 2019 meta-analysis (including six randomized, controlled trials) reported that for plantar fasciitis, LLLT offered at least three months of relief of heel pain.

In a review of seven studies including 384 patients with nonspecific LBP, three studies showed that LLLT was more effective than sham laser at reducing pain for as long as six months. In those patients, however, the degree of pain reduction was small. On the other hand, three studies reported that LLLT with exercise was not better than exercise alone or exercise plus sham laser. The authors concluded, “There are insufficient data to either support or refute the effectiveness of LLLT for the treatment of LBP.”

The more recent 2017 study on LLLT in carpal tunnel syndrome identified 22 trials that randomized 1,153 participants to LLLT versus, variably, placebo, ultrasound, steroid injection, splinting, etc. As with many reviews, the included studies were criticized for variable treatment approaches, a high risk of bias, and imprecise estimates of effect size. The authors concluded, “There was insufficient evidence to show whether LLLT is better or worse in the management of carpal tunnel syndrome than other nonsurgical interventions.” The following year, Franke et al., published another systematic review reporting short-term (less than five weeks) but not long-term benefits of LLLT in carpal tunnel syndrome.

Use in the United States

Orthopaedic surgeons may have markedly different levels of exposure to LLLT. In some parts of the world, the modality has been prevalent for decades. In a 2017 article, Sergey Moskvin reported that the therapy has been in continuous use in Russia since 1964. Currently, there are more than 400,000 therapeutic devices (wavelength 635 nm, power 5 W to 40 W, pulse duration 100 ns, frequency 10,000 Hz) in use in that country. Popularity of the devices in the United States has been slower to grow, although the current opioid crisis has redoubled interest in other modalities for pain relief. In Austin, Texas, I found six centers advertising the service on Google. They ranged from physical therapy and chiropractic practices to wellness and longevity clinics.

Although many of the devices are FDA-approved for pain relief indications across a wide spectrum of medicine, limited insurance coverage and the multiple visits often required for use lead to limited utilization. Industry site and laser vendor ColdLasers.org offers some excellent practical and taxonomic information about LLLT. It notes that for patients, each session costs $30 to $200. The lasers themselves vary from $2,000 to $15,000, and there are dozens of manufacturers selling disparate devices.

Some therapies qualify for insurance reimbursement with Current Procedural Terminology code 97026 (infrared therapy). When treatments are performed by licensed practitioners, payments can utilize health savings accounts.

AAOS has not taken a formal position on LLLT.

Manufacturers’ claims are grandiose, but it’s hard to come away from the data thinking that LLLT does not offer some real benefits to some patients. Having little direct experience with LLLT, given its potential for modest benefit in the absence of serious risk, I would neither offer nor persuade LLLT for my patients with back pain. If you have thoughts or experience with these techniques, share them with AAOS Now Publisher Dennis Coyle at coyle@aaos.org.

Eeric Truumees, MD, is the chair of the AAOS Now Editorial Board, editor-in-chief of AAOS Now, and an orthopaedic spine surgeon in Austin, Texas, where he is also professor of orthopaedics at the Dell Medical School, University of Texas.

References 

1. ClinicalTrials.gov: Study of Low Level Laser Therapy to Treat Low Back Pain. Available at: https://www.clinicaltrials.gov/ct2/show/NCT01835756. Accessed August 16, 2019.
2. Krebs EE, Gravely A, Nugent S, et al: Effect of opioid vs nonopioid medications on pain-related function in patients with chronic back pain or hip or knee osteoarthritis pain: the SPACE randomized clinical trial. JAMA 2018;319:872-82.
3. Liu KH, Liu D, Chen YT et al: Comparative effectiveness of low-level laser therapy for adult androgenic alopecia: a system review and meta-analysis of randomized controlled trials. Lasers Med Sci 2019;34:1063-9.
4. Chen Y, Chen XL, Zou XL et al: Efficacy of low-level laser therapy in pain management after root canal treatment or retreatment: a systematic review. Lasers Med Sci 2019 May 1.
5. Langella LG, Casalechi HL, Tomazoni SS, et al: Photobiomodulation therapy (PBMT) on acute pain and inflammation in patients who underwent total hip arthroplasty—a randomized, triple-blind, placebo-controlled clinical trial. Lasers Med Sci 2018;33:1933-40.
6. Kibar S, Konak HE, Evcik D, et al: Laser acupuncture treatment improves pain and functional status in patients with subacromial impingement syndrome: a randomized, double-blind, sham-controlled study. Pain Med 2017;18:980-7.
7. Yeh SW, Hong CH, Shih MC, et al: Low-level laser therapy for fibromyalgia: a systematic review and meta-analysis. Pain Physician 2019;22:241-54.
8. Wang W, Jiang W, Tang C, et al: Clinical efficacy of low-level laser therapy in plantar fasciitis: a systematic review and meta-analysis. Medicine (Baltimore) 2019;98:e14088.
9. Yousefi-Nooraie R, Schonstein E, Heidari K, et al: Low level laser therapy for nonspecific low-back pain. Cochrane Database Syst Rev 2008:CD005107.
10. Rankin IA, Sargeant H, Rehman H, et al: Low‐level laser therapy for carpal tunnel syndrome. Cochrane Database Syst Rev 2017:CD012765.
11. Franke TP, Koes BW, Geelen SJ, et al: Do patients with carpal tunnel syndrome benefit from low-level laser therapy? A systematic review of randomized controlled trials. Arch Phys Med Rehabil 2018;99:1650-9.
12. Moskvin SV: Low-level laser therapy in Russia: history, science and practice. J Lasers Med Sci 2017;8:56-65.

Expert opinions

I asked two colleagues, E. Kano Mayer, MD, a physical medicine and rehabilitation sports and spine specialist, and Trent McGinty, DPT, a physical therapist, to consider the evidence, share their experience, and offer their sense of the utility of low-level laser therapy (LLLT).

Dr. Mayer

Avedis Donabedian is well known for seminal papers giving medical professionals a rubric to evaluate “treatment efficacy.” Evaluating the efficacy of pain treatments presents a challenge. In the vast majority of cases, functional improvement has far greater “face validity” than transient analgesia. When evaluating functional improvement, recurrent cost weighs less than the recurrent costs for analgesia-only treatments (without improved function).

LLLT data can be misleading because the biological mechanisms for laser (in the ultraviolet spectrum) are likely different from the more commonly employed LED therapy. Furthermore, most of the LLLT data are solely dependent on claims of analgesia. Those claims should also be evaluated in the context of “durability of benefit,” “cost,” and “adjunctive treatments,” but those measures are missing in the majority of the available data on PubMed.

I have other concerns about the purported benefits reported for LLLT. First, animal data have never been a predictable proxy for human efficacy. The data cited in some of the clinical review articles that include canine, rodent, and feline models should not be taken as “evidence.” Second, penetrance is on the order of 5 mm to 2 cm, which corresponds with the improvements reported for morning stiffness in rheumatoid arthritis, hand pain in osteoarthritis (OA), elbow tendonitis/bursitis, and plantar fasciitis. The lack of evidence in placebo-controlled trials for hip and knee OA and chronic, nonspecific low back pain seems to support the hypothesis that limited tissue penetrance by photons due to body habitus are important considerations when evaluating potential treatment efficacy. Claims for spine or major-joint functional improvements in humans compared to other treatments lack “face validity.”

Novel Food and Drug Administration (FDA) indications for LLLT or LED therapy around fibromyalgia, widespread pain, central sensitization, chronic fatigue, and more seem to lack the all-important face validity. Notably, articles in PubMed boasting low P values around these difficult-to-diagnose conditions conspicuously lack durability measures in their data.

Considering that similar tissue effects and functional improvements may be achieved by exercise, ultrasound, or diathermy, caution should be taken when physicians recommend LLLT or LED therapy. Out-of-pocket costs may unduly influence patient feedback to referring orthopaedic surgeons. Be vigilant of the value equation. Scrutinize cost when the benefit of a therapy is uncertain.

Mr. McGinty

I called an Erchonia representative and asked about device costs. Its small, handheld device sells for $7,900. The FX 635 device that was recently approved by the FDA for whole-body musculoskeletal pain costs $40,000. For a physical therapy clinic, this is quite an investment for likely limited reimbursement. In Austin, Texas, five chiropractors currently own them and, I imagine, offer treatments for cash only.

As with most treatments, the efficacy of LLLT is likely dependent on the type of laser, the setting/dosage, and the skill of the practitioner administering the treatment. To me, it looks like the benefits outweigh the risks at this point. The patient and provider must decide together which treatment options are both the most effective and still cost-effective. It will be interesting to see how reimbursement trends shift in the wake of the additional FDA approvals. Lastly, as with most modalities, LLLT should be used only as an adjunct to a thorough, mechanical exam focused on functional gains and objective measures over subjective reports.

The manufacturer weighs in

Steve Shanks

As you know, medical device manufacturers sometimes market devices illegally and unethically to make money. They may make statements such as “more power” and “better penetration,” which are nothing more than marketing gimmicks that have nothing to do with clinical validation. For example, if a therapeutic dose of a nonsteroidal anti-inflammatory drug is 200 mg, taking 20 g would not make the drug better—it would actually cause a lot of side effects.

It is the same with laser therapy.

The accompanying article cited ColdLasers.org, which is a perfect example. Most of the devices they sell do not have Food and Drug Administration (FDA) 510k market clearance or are topical heating devices cleared for muscle relaxation. The website makes marketing statements that are against federal and state laws, which is illegally marketing the device. They state that class I and II devices can be sold “over the counter” (OTC). The only cold laser (low power) that has 510k clearance for OTC use is Erchonia’s Zerona for fat reduction. We had to perform a clinical trial to make the device OTC. Any laser that is not sold to a doctor would be illegal.

ColdLasers.org states that the only cold or low-power laser they sell is Microlight and that they have one used laser. All other lasers that they market are FDA exempt (ILY), as long as they market topical heating and muscle relaxation. This is not the case, as the same webpage lists protocols for arthritic thumb and diabetic neuropathy, for which no laser has FDA 510k clearance. They also list low back pain; however, the only company that has a 510k for low back pain is Erchonia, and we do not sell any devices to this company.

The term cold lasers was implemented more than 20 years ago to distinguish heating lasers (ILY) from biostimulation lasers (NHN) that do not heat the skin. ColdLasers.org mixes both for marketing purposes because no heating laser has ever submitted any clinical research to obtain a 510k market statement, and they are practically equivalent to heat lamps. This is an example of unethical and illegal marketing.

There are two device classes for therapeutic lasers: ILY, which is for topical heating and was grandfathered in because heat lamps were around before the FDA Modernization Act of 1976. This category includes heating pads, diathermy, and lasers that heat the skin. Although the FDA made the ILY category exempt in 2017, ILY devices are still class II medical devices if they are advertised for topical heating and emit between 700 nm to 50,000 nm. Unfortunately, adherence to those limits is poor because no one would buy a $30,000 laser that is practically equivalent to a heat lamp.

The other category for therapeutic lasers is NHN. Erchonia created this category in 2002 when we performed two level I clinical trials on chronic neck and shoulder pain. Very few lasers are in this category, as the FDA requires research evidence before it issues a 510k or marketing statement for the NHN category. Any manufacturer can obtain 510k clearance in this category, but it requires level I clinical research, which is not what unethical medical device companies do.

It is easier to state that you have FDA clearance because many doctors have no idea what that means, and manufacturers continue to illegally market their devices.

Erchonia’s devices are FDA 510k cleared for the purposes for which they are marketed. We have 17 different FDA 510k statements, all of which are based on level I research. We are trying to validate low-level laser technology and do not want the FDA to sanction us for illegally marketing our devices.

Steve Shanks is the president of Erchonia Corp.