If you are considering MLS laser therapy for orthopedic pain, the most useful question is not simply whether laser therapy “works.” The better question is: for which condition, for which goal, and as part of what overall treatment plan?
Laser therapy is often marketed with broad claims about pain, inflammation, circulation, tissue repair, and recovery. Some of those claims are supported by promising clinical research. Others are based more heavily on laboratory studies, device theory, or manufacturer information. The evidence also varies substantially by diagnosis, laser wavelength, energy dose, treatment schedule, and whether laser is used alone or alongside exercise and physical therapy.
My approach is to keep laser therapy in the right lane. It may be a useful adjunct for symptom relief in selected patients, but it should not replace an accurate diagnosis, progressive rehabilitation, or a treatment that addresses a structural problem when one is needed.
Pacific Bone & Joint offers MLS laser therapy in Honolulu as a non-invasive option that can be integrated into a broader orthopedic or rehabilitation plan.
What is MLS laser therapy?
MLS stands for Multiwave Locked System. The device used in this form of therapy delivers synchronized light at two wavelengths. The goal is to expose tissue to light energy without cutting, burning, or creating an incision.
The broader scientific term is photobiomodulation, often abbreviated PBM. Older research frequently uses terms such as low-level laser therapy, cold laser therapy, or LLLT. Newer devices can use different power levels, wavelengths, pulse patterns, and treatment doses.
That distinction matters.
A study showing benefit from one photobiomodulation protocol does not automatically prove that every laser device, every setting, or every treatment schedule will produce the same result. This is one of the biggest reasons laser research can appear confusing.
So, does MLS laser therapy actually work?
The most accurate answer is: photobiomodulation has evidence for short-term pain relief in some musculoskeletal conditions, but the certainty and consistency of evidence vary, and the research is not equally strong for every condition or every specific laser system.
That is very different from saying laser therapy is a cure.
For many orthopedic problems, the best-supported role is as an adjunct. If laser reduces pain enough to help a patient walk more comfortably, tolerate strengthening, sleep better, or participate more effectively in rehabilitation, that can be clinically useful even if the laser itself is not correcting the underlying anatomy.
What does the research show for knee arthritis?
Knee osteoarthritis is one of the better-studied orthopedic uses of photobiomodulation.
A 2024 systematic review and meta-analysis in Physical Therapy evaluated 10 randomized, placebo-controlled studies involving 542 participants with knee osteoarthritis. The authors found that photobiomodulation reduced pain at rest compared with placebo and may improve disability. However, they rated the certainty of the evidence as very low because the included studies had important limitations and risk of bias. Their conclusion was appropriately cautious: photobiomodulation could be considered as a complement to established therapies, but the evidence did not support relying on it as an isolated treatment. Read the 2024 systematic review.
That fits how I think about it clinically.
For knee arthritis, the foundations of nonoperative care remain treatments such as exercise, strengthening, activity modification, weight management when appropriate, medications when safe, bracing in selected patients, and injections for certain situations. The American Academy of Orthopaedic Surgeons continues to emphasize evidence-based nonoperative management rather than any single passive modality. See the AAOS knee osteoarthritis guideline.
Laser may be reasonable when the goal is to reduce symptoms enough to make those foundational treatments easier to perform.
Does adding laser to exercise make exercise work better?
This is where the evidence becomes mixed.
A 2021 systematic review examined photobiomodulation combined with exercise for knee osteoarthritis. Only two higher-quality trials in that review found an additional benefit from laser, and the authors highlighted substantial differences in dosing, devices, and exercise programs across studies. Read the systematic review.
A later randomized trial published in 2023 found that adding photobiomodulation to a strengthening program did not provide meaningful incremental benefit over strengthening with placebo laser. Read the randomized trial.
That does not mean laser never helps knee pain. It means the evidence does not justify telling every patient with arthritis that laser will make a good exercise program substantially better.
What about tendon pain and plantar fasciitis?
The evidence is also encouraging, but not definitive, for several tendon-related conditions.
A 2022 systematic review and meta-analysis of randomized trials evaluated low-level laser therapy for lower-extremity tendinopathy and plantar fasciitis. When recommended treatment doses were used, the authors found improvements in pain and disability in the short to medium term. They also noted that long-term data were unavailable and that uncertainty remained because many trials were small. Read the BMJ Open review.
A newer 2025 systematic review of 35 controlled trials also found short-term pain reduction for chronic tendinopathy compared with minimal intervention. Importantly, the authors emphasized that treatment parameters and the number of sessions influenced results. Read the 2025 review.
For a patient with Achilles tendinopathy, patellar tendinopathy, tennis elbow, or plantar fasciitis, I would still view progressive loading and rehabilitation as the center of treatment. Laser may be considered when pain is limiting that progression.
Can laser speed recovery after knee replacement?
This is an interesting area, but I would not oversell it.
A 2025 scoping review identified only three clinical studies evaluating photobiomodulation after total knee arthroplasty. Those studies reported potentially favorable effects on pain, swelling, range of motion, and function. That sounds promising, but three studies are not enough to conclude that laser should be routine after every knee replacement. Read the scoping review.
For a knee-replacement patient, the priorities remain wound safety, swelling control, restoring extension and flexion, walking, rebuilding quadriceps strength, and progressively returning to function. Laser might be one supportive tool within that recovery pathway, not the pathway itself.
Is MLS laser the same as the lasers used in these studies?
Not necessarily, and this is an important limitation.
MLS is a specific commercial laser technology. Published photobiomodulation studies use a wide range of wavelengths, power settings, energy doses, pulse patterns, treatment locations, and session schedules. Some studies use low-level lasers. Others evaluate higher-intensity systems or mixed light sources.
Because of that variability, it would be scientifically inappropriate to take every positive photobiomodulation study and claim that it proves the same benefit for every MLS protocol.
What the broader literature can tell us is that light-based photobiomodulation can have clinically measurable effects in some musculoskeletal conditions. What it cannot yet tell us with high certainty is the ideal device and exact protocol for every patient and diagnosis.
What laser therapy cannot do
This is where expectations matter most.
MLS laser therapy should not be described as something that can:
- Regrow worn-away joint cartilage in advanced osteoarthritis
- Repair a completely torn ACL
- Reattach a ruptured tendon
- Stabilize a displaced fracture
- Eradicate a bone or joint infection
- Reverse a loose or failed joint replacement
- Replace rehabilitation when weakness, mobility, or movement control is the main problem
Pain improvement is valuable, but feeling better and fixing the underlying structural problem are not always the same thing.
If a treatment makes a painful knee more comfortable for a period of time, that may be worthwhile. But it should not delay evaluation of progressive weakness, instability, locking, deformity, infection, fracture, or another condition that requires a different treatment.
When might laser therapy be reasonable?
I think it is most reasonable to discuss laser when three things are true:
- We understand the diagnosis. Treating “pain” without knowing its source can waste time and money.
- The treatment goal is realistic. Usually that means symptom relief or supporting rehabilitation, not promising tissue regeneration.
- Laser fits into a broader plan. It may complement strengthening, mobility work, activity modification, or other evidence-based care.
Examples might include a patient with symptomatic knee arthritis who is trying to stay active, someone with a chronic tendon problem whose pain is limiting rehabilitation, or a recovering patient in whom a clinician believes symptom control could make therapy more tolerable.
When should you get an orthopedic evaluation before trying laser?
Laser should not become a detour around diagnosis.
An orthopedic evaluation is more important first if you have:
- A new injury with inability to bear weight
- Significant deformity after trauma
- A joint that repeatedly gives way or locks
- Rapidly increasing swelling
- Fever, redness, drainage, or concern for infection
- New numbness or progressive weakness
- Persistent pain that has not been explained
- Pain around a joint replacement that is worsening
- Symptoms that continue despite an appropriate course of conservative treatment
In those situations, the question is not “Which pain-relief modality should I try next?” The question is “What is causing this, and is there something important that needs to be treated?”
Why physical therapy still matters
Passive treatments can make a patient feel better. Rehabilitation is often what helps turn that symptom improvement into better function.
For arthritis and many tendon problems, exercise and progressive loading remain central components of treatment. The 2019 American College of Rheumatology and Arthritis Foundation guideline strongly recommends exercise for knee and hip osteoarthritis. Read the guideline.
That is why we often think of laser as something that may work with physical therapy at Pacific Bone & Joint, rather than instead of it.
If a treatment decreases pain for a few hours or days but the patient never restores strength, mobility, balance, or capacity, the opportunity has been missed. The useful question is whether symptom relief helps you move forward.
What should you expect during an MLS laser session?
Treatment is non-invasive. There is no incision and no injection. A clinician positions or moves the treatment applicator over the selected area while appropriate eye protection is used.
Session length and treatment frequency depend on the condition and the protocol selected. Because laser dosing matters in the research, I do not think patients should assume that “more power” or “more sessions” automatically means better treatment.
A thoughtful plan should identify what is being treated, what outcome is being monitored, and how long it is reasonable to continue before deciding whether the treatment is helping.
How do you know whether it is worth continuing?
Before starting, pick a functional target instead of judging treatment only by how you feel immediately afterward.
Useful targets might include:
- Walking farther before pain starts
- Sleeping with fewer pain interruptions
- Tolerating a strengthening session better
- Going up and down stairs more comfortably
- Improving a measured range of motion
- Returning to a specific work or recreational activity
If there is no meaningful progress after a reasonable trial, simply repeating the same treatment indefinitely is not a strategy. The diagnosis and plan should be reassessed.
Is MLS laser therapy safe?
Photobiomodulation is generally described as non-invasive and is well tolerated in musculoskeletal studies. In the 2022 lower-extremity tendinopathy and plantar fasciitis review, no adverse events were reported in the included trials.
Still, a Class IV therapeutic laser is medical equipment, not a home flashlight. Proper training, dosing, treatment selection, and eye protection matter. Your clinician should also review whether there is any reason the treatment is inappropriate for your specific situation.
Questions to ask before paying for laser therapy
Patients deserve a clearer conversation than “this laser heals everything.”
Ask:
- What diagnosis are we treating?
- What is the specific goal of laser in my case?
- What evidence exists for my condition?
- Is laser replacing something with stronger evidence, or complementing it?
- How many sessions would constitute a reasonable trial?
- What outcome will we use to decide whether it is working?
- What happens if I do not improve?
- What will it cost, and is my insurance expected to cover it?
Those questions keep the treatment focused on value rather than technology for technology’s sake.
My perspective on MLS laser therapy
I like technologies that solve a patient problem. I do not like technology simply because it sounds advanced.
The current literature suggests that photobiomodulation can reduce pain in some musculoskeletal conditions, particularly in the short term. At the same time, study quality is variable, protocols are inconsistent, and evidence from one laser system should not automatically be generalized to another.
So my position is straightforward: MLS laser therapy can be a reasonable supportive option for selected patients, especially when symptom relief helps them participate in rehabilitation or remain active. It is not a cure, and it should not replace diagnosis or proven treatment.
If you are considering laser therapy for knee arthritis, tendon pain, or orthopedic recovery, an evaluation can help determine whether it fits your diagnosis and goals or whether another treatment makes more sense.
Sources and further reading
- Oliveira S, et al. Effectiveness of Photobiomodulation in Reducing Pain and Disability in Patients With Knee Osteoarthritis: A Systematic Review With Meta-Analysis. Physical Therapy. 2024. PubMed
- Vassão PG, et al. Association of photobiomodulation therapy and exercise programs in pain and functional capacity of patients with knee osteoarthritis: a systematic review of randomized trials. Lasers in Medical Science. 2021. PubMed
- Naterstad IF, et al. Efficacy of low-level laser therapy in patients with lower extremity tendinopathy or plantar fasciitis: systematic review and meta-analysis of randomised controlled trials. BMJ Open. 2022. PubMed
- Yap BWD, Lim ECW. Shedding more light on the short-term effect of low-level laser therapy on pain in tendinopathy: A systematic review with meta-analysis. Journal of Back and Musculoskeletal Rehabilitation. 2025. PubMed
- Kolasinski SL, et al. 2019 American College of Rheumatology/Arthritis Foundation Guideline for the Management of Osteoarthritis of the Hand, Hip, and Knee. Arthritis Care & Research. 2020. PubMed
- American Academy of Orthopaedic Surgeons. Management of Osteoarthritis of the Knee (Non-Arthroplasty), Third Edition. 2021. AAOS
