Osteoarthritis is broadly understood as a degenerative “wear and tear” disease caused by an accumulation of micro-traumas to the articular cartilage. Traditional treatment methods aim to manage pain and prevent surgery, but make no attempt to heal cartilage trauma. Recent developments in regenerative medicine have found laser therapy effective to increase joint flexion, reduce pain and increase quality of life in patients with osteoarthritis of the knee, which is great news for the 20 million Americans who live with this debilitating condition.
Symptoms of Knee Osteoarthritis
Pain, stiffness, and decreased mobility are hallmark symptoms of knee osteoarthritis. As we age the repetitive stress of daily living slowly deteriorates the cartilage in our knees. This deterioration is exacerbated by carrying extra body weight; just one extra pound of weight adds 4 extra pounds of pressure to the knees. Joint health can also be compromised from occupational stress as with manual laborers or from repetitive micro-traumas from recreational sports like soccer and tennis.
Common Osteoarthritis Treatment Options
Traditional interventions aim to manage symptoms, such as weight loss when indicated and physical therapy to strengthen surrounding muscle groups and realign articulation.¹ Non-steroidal anti-inflammatory drugs may offer short term pain relief, but do not protect joints from cartilage loss.² Hyaluronic acid (HA) naturally occurs in joints and studies have shown high-molecular-weight HA injections may help increase joint cushioning, but only slightly more than placebo.³
Improve Outcomes for Patients with Knee Osteoarthritis with Laser Therapy
Once articular cartilage is damaged, it is difficult for the body to repair. Tissue repair generally depends on healthy blood flow, but cartilage is nonvascular tissue which receives nutrients via synovial fluid. Laser therapy has emerged as a regenerative option which supports the healthy formation of cartilage. Recents studies have found pain reduction and increased joint flexion in cartilage tissues irradiated with near infrared light. In one study published in 2009, researchers in Hungary administered laser therapy with an 830 nm wavelength diode at 8 points over the femoral and tibial condyles. Each patient received 8 therapy sessions over 4 weeks at a dosage of 6J/point or 48J/cm². The treatment group saw significant improvement in all parameters including pain, pressure sensitivity, and flexion. Positive effects from the therapy were still evident at the final 2-month follow up.⁴
Decrease Pain with Laser Therapy
Another study combined the use of laser therapy with exercise and again found statistically significant improvements to pain levels, knee function and quality of life. The study design included 3 groups; laser therapy at a dosage of 3J/cm² plus exercise, laser therapy at 2J/cm² with exercise or placebo laser with exercise. All participants received 10 treatment sessions over a two week period.⁵
How does Laser Therapy Improve Joint Health?
Arthritic conditions have been linked to excessive inflammation and laser therapy reduces inflammation by increasing cellular metabolism. Reduced inflammation creates healthier joint conditions. Additionally, studies have linked laser therapy to increased expression of osteoglycin gene. Osteoglycin is a small leucine-rich proteoglycan (SLRP) which appears throughout bone, cartilage and connective tissues and is thought to regulate proliferation, differentiation and adhesion along with collagen and other growth factors. Osteoblasts irradiated with light show a .5-2 fold increase in osteoglycin expression which would support increased cartilage formation, therefore reducing friction and pain while increasing flexion in the osteoarthritic knee.⁶
Deyle GD, Allison SC, Matekel RL, et al. Physical therapy treatment effectiveness for osteoarthritis of the knee: a randomized comparison of supervised clinical exercise and manual therapy procedures versus a home exercise program. Phys Ther. 2005;85(12):1301-17.[ncbi]
Pinals RS. Pharmacologic treatment of osteoarthritis. Clin Ther. 1992;14(3):336-46.[ncbi]
Lo GH, Lavalley M, Mcalindon T, Felson DT. Intra-articular hyaluronic acid in treatment of knee osteoarthritis: a meta-analysis. JAMA. 2003;290(23):3115-21.[ncbi]
Hegedűs B, Viharos L, Gervain M, Gálfi M. The Effect of Low-Level Laser in Knee Osteoarthritis: A Double-Blind, Randomized, Placebo-Controlled Trial. Photomedicine and Laser Surgery. 2009;27(4):577-584. doi:10.1089/pho.2008.2297.[ncbi]
Gur A, Cosut A, Sarac AJ, Cevik R, Nas K, Uyar A. Efficacy of different therapy regimes of low-power laser in painful osteoarthritis of the knee: a double-blind and randomized-controlled trial. Lasers Surg Med. 2003;33(5):330-8.[ncbi]
Hamajima S, Hiratsuka K, Kiyama-kishikawa M, et al. Effect of low-level laser irradiation on osteoglycin gene expression in osteoblasts. Lasers Med Sci. 2003;18(2):78-82.[ncbi]