What are Hyaluronic Acid Injections?
Hyaluronic acid (HA) is a naturally occurring molecule found in the body, particularly in the skin, joints, and connective tissues. It is a type of glycosaminoglycan, a long-chain carbohydrate molecule that is composed of repeating disaccharide units. HA is highly hydrophilic, meaning it has a strong affinity for water, and can hold up to 1,000 times its weight in water.
In the body, HA plays a crucial role in lubricating joints, cushioning and hydrating tissues, and maintaining skin elasticity. In skincare, HA is used as an ingredient in moisturizers, serums, and other products to hydrate and plump the skin, reduce the appearance of fine lines and wrinkles, and improve overall skin texture and tone. In joint injections, hyaluronic acid is used as a lubricant and cushioning agent to help alleviate pain and improve mobility in people with osteoarthritis. (link to osteoarthritis page)
Typically, people with osteoarthritic knee pain who have not responded well to conservative treatments such as physical therapy and pain medication may be good candidates for hyaluronic acid injections into their knee.
Hyaluronic acid injections work by supplementing the hyaluronic acid that naturally occurs in the synovial fluid of the knee joint. In people with osteoarthritis, the synovial fluid can become thinner and less viscous, which can lead to joint pain and stiffness.
Hyaluronic acid injections are intended to mimic the natural lubricating properties of the synovial fluid and help improve joint function. The injections are believed to work by:
Improving joint lubrication: The hyaluronic acid in the injections helps lubricate the joint and reduce friction between the bones, which can help improve joint function and reduce pain.
Stimulating the production of natural hyaluronic acid: Hyaluronic acid injections may stimulate the production of the body's own hyaluronic acid, which can help improve joint health over the long term.
The exact mechanism of action of hyaluronic acid injections is not fully understood, and it is possible that the injections work through a combination of these and other factors. However, the overall goal is to improve joint function and reduce pain and stiffness in people with knee osteoarthritis.
Many studies have been conducted to evaluate the effectiveness of these injections, and the results have been generally positive. Several systematic reviews and meta-analyses of clinical trials have found that hyaluronic acid injections can be effective in reducing knee pain and improving joint function in people with knee osteoarthritis. However, some studies have reported that hyaluronic acid injections are no more effective than placebo injections or other conservative treatments such as physical therapy, while others have reported conflicting results. The effectiveness of the injections may depend on various factors, such as the severity of the osteoarthritis, the duration of the treatment, the type of injection used, and individual patient factors.