Laser therapy is an alternative treatment for some types of pain, such as that often associated with the knee. Research on laser therapy is preliminary, and most insurers still consider it to be experimental. However, some studies show it can alleviate pain, including knee pain.
Laser therapy is also known as cold laser therapy, class III laser therapy, or low-level laser therapy (LLLT). Some early studies have shown lasers might help wounds heal. If true, this suggests they could help the body to repair tissue damage caused by injuries and arthritis or other diseases. However, the first studies of cold therapy lasers were not controlled clinical studies.
Laser therapy is relatively new, and researchers do not yet know if it has any long-term risks. Most studies have looked at short-term effects, so it is possible that laser therapy could trigger longer-term side effects that have not yet been realized.
Fast facts on laser therapy for knee pain:
- Proponents of laser therapy say it offers both temporary pain relief and long-term healing.
- Supporters of laser therapy suggest it could treat ailments as diverse as arthritis, chronic pain, joint disorders, and even addictions, such as smoking.
- Research on pain in other areas of the body suggests that laser therapy can, as a minimum, offer temporary pain relief.
- Unlike surgical lasers, cold lasers do not heat up the body’s tissues.
Surgical lasers are increasingly common in medicine and cut more precisely than traditional surgical equipment, reducing the risk of injury and helping speed up surgery.
However, these “hot” lasers can be dangerous when incorrectly used. On the other hand, the “cold” lasers used in LLT to treat pain are much weaker than surgical lasers and cannot cut through or burn skin.
Proponents of laser therapy argue that the skin absorbs very little light, allowing a laser to penetrate deeply into tissue. This lets it heal damaged tissue with no side effects. And because the wattage is very low, there is no risk of a burn.
Experts are unsure of the answer to this question.
Most research has focused on osteoarthritis and chronic pain. If laser therapy does work, it is unclear how or why. The lasers might improve circulation, support cell health, release endorphins that fight pain, reduce inflammation, or encourage the growth of new, healthy tissue.
Preliminary research is promising. But there is no conclusive proof that cold therapy lasers can treat pain or any underlying medical condition. Many insurers, as well as Medicare and Medicaid, do not cover laser therapy.
What do the clinical studies say?
A 2005 Cochrane review assessed the ability of LLT to reduce the pain of rheumatoid arthritis, a common cause of knee pain. It found evidence for moderate short-term pain relief with few side effects.
Because it is unclear how laser therapy works, it is not known whether the results of these studies can be applied to the knee.
A 2008 study looked at previous randomized, placebo-controlled studies of LLT for treating tennis elbow. The studies included in the analysis did not look at how or why laser therapy reduced pain and did not measure long-term pain relief.
A 2009 analysis looked at previous research on laser therapy for neck pain. The study found significant pain relief ,lasting up to 22 weeks. While some people experienced side effects, these effects were no different from those experienced from a placebo.
Why is it so hard to determine if it works?
One of the problems with laser therapy is that different studies look at different wavelengths of light. This makes it difficult to compare one laser to another. Likewise, different manufacturers make different recommendations about treatment frequency and duration.
For laser therapy to become a standard treatment for knee pain, doctors would need to know which wavelength is most effective and at what dosage.
The lasers used in this type of therapy are cold, so there is little risk of serious side effects. Most studies have found no side effects. When studies do find side effects, they are minor and similar to the side effect of a placebo. As the lasers are cold and less powerful than other medical lasers, it is unlikely that they can cause serious health issues.
Little research has shown that laser therapy offers long-term relief. For people seeking affordable relief, there are often better options, including treating the underlying causes of pain, such as rheumatoid arthritis.
Home management strategies, such as rest, ice packs, compression, heat, massage, stretching, exercise, and the use of over-the-counter medications, can all offer temporary relief for minor knee pain.
For chronic or severe knee pain some treatments may offer relief. These include:
- strengthening exercises
- physical therapy
- knee injections, hyaluronic acid supplements and corticosteroids
- arthrocentesis, involving removal of joint fluid through a needle
- prescription non-steroidal anti-inflammatory drugs (NSAIDs)
- arthritis medications, such as biologics, anti-rheumatics, corticosteroids, and pain relievers
- alternative treatments, such as acupuncture and chiropractic care
- knee surgery
Laser therapy can work alongside these treatments, so trying laser therapy does not mean having to forgo other options.