Knee pain affects approximately one-third of all Americans at any given point, with as many as 10 million suffering from severe joint pain. Knee pain is the second most common kind of chronic pain. It is often associated with osteoarthritis, a degenerative joint disease wherein the cushioning cartilage between the bones deteriorates. Osteoarthritis is a progressive illness, and the damage it causes cannot be reversed. But it can be managed and slowed down. In some cases, hyaluronic acid injections can play a role in managing the symptoms of osteoarthritis and preventing further pain.
What Is Hyaluronic Acid?
Hyaluronic acid is not confused with corrosive acids commonly used in cleaning or industrial applications. To put it simply, hyaluronic acid is a mechanical lubricant that the body produces. As a substance, it is gooey and viscous. Alongside other organic compounds like collagen, hyaluronic acid plays a role in keeping your eyes, joints, and skin supple and moisturized.
- Hold a lot of water. A fraction of a teaspoon of hyaluronic acid can hold well over a gallon of water. This incredible level of water retention makes hyaluronic acid an essential moisturizer and one of the reasons certain parts of the body, like the surface of our eyes and skin, retain water so well.
- Help things move around with less friction. Friction can be harmful – especially between the more challenging parts of our body, our bones. Hyaluronic acid acts as a natural lubricant, in addition to the protective impact-absorbing cartilage we have in our joints.
- Create more supple skin. Hyaluronic acid helps reduce wrinkles. Oral hyaluronic acid has been a common skin supplement for some time.
- Improve wound healing and prevent scarring. Whereas hyaluronic acid helps reduce wrinkles, the same effect can drastically reduce the degree to which skin scars. Hyaluronic acid can also help prevent the formation of keloids, which are large hypertrophic scars.
However, while hyaluronic acid is something the body produces on its own, there are conditions wherein an additional supplementation of hyaluronic acid can help prevent pain or other illnesses. For example, hyaluronic acid is used in cosmetic medicine and dermatology to reduce scarring. It is also used in treating dry eyes or as eye drops to help keep your eyes moisturized. We produce hyaluronic acid through two main methods:
- Microbial fermentation in a lab environment, where a unique bacterial strain is fermented using grains like soy or wheat to yield hyaluronic acid.
- Animal sources, which are more frequently used when the closest possible analog is needed.
In most cases, rooster combs (the red part atop the head) provide medical hyaluronic acid. In joint diseases, such as osteoarthritis, hyaluronic acid can help reduce pain by affecting the degree to which your bones have contact.
What Are Hyaluronic Acid Injections Used For?
Just like pistons in a cylinder, the friction between bones caused by a loss in cartilage can lead to abrasions on both sides. Unlike an engine, bone abrasions can also result in painful bony growths (called bone spurs) and nerve pain. Hyaluronic acid can help prevent this for some time, the same way motor oil lubricates the cylinders of an engine block. Hyaluronic acid is sold in many different forms.
It can be taken orally, applied as eye drops, or as the active ingredient in a topical ointment. But when applied for knee pain, it must be applied via injection. Hyaluronic acid injections target the area where the cartilage has broken down enough to require medical intervention. The mechanism of action behind a hyaluronic acid injection for the knees is threefold.
- First, the acid itself acts as a natural lubricant. It helps reduce bone-on-bone friction and improve shock absorption.
- Second, the acid applies an anti-inflammatory effect to the knee cartilage. The less cartilage and narrow the gap between the joint and bones, the less effective the injection may be. But if the tissue is still intact, the hyaluronic acid can provide relief through an anti-inflammatory effect.
- Third, the acid helps protect nerve endings and slows the release of pain signals from the knee. The acid itself is believed to form a protective barrier around nerves in the knee.
Hyaluronic acid is far from a panacea, however. It is not used often and is never used as a first-line treatment. Studies on the results of hyaluronic acid injections for osteoarthritic knee pain are mixed. But not all of them report positive results. Furthermore, you may not be eligible for a hyaluronic acid injection. Specific contraindications rule out injections such as a hyaluronic acid injection for knee pain, including blood clotting illnesses, a recent infection, pregnancy, and joint effusion. However, a patient eligible for a hyaluronic acid injection can bring lasting relief.
Are Hyaluronic Acid Injections an Effective Long-Term Treatment?
Hyaluronic acid can result in long-lasting pain relief. One injection can last for as long as 3 to 6 months, with the most significant effects reported between weeks 5 and 14. In most cases, the best results are achieved through a round of multiple injections over a series of appointments, rather than just one injection. But it is not a long-term treatment option for osteoarthritis in the knee or elsewhere. Osteoarthritis is a progressive illness. Once it starts, your affected joints will continue to deteriorate. However, you can control the deterioration somewhat and affect your quality of life through improved diet, exercise, and pain management.
Hyaluronic acid may be part of a long-term pain relief strategy. But true long-term relief is usually achieved through regular physical activity, a healthy diet, and frequent check-ups with your physician. In extreme cases, your osteoarthritis may require surgery to remove swollen tissue or unwanted bone growths, which can significantly contribute to pain symptoms. Is a hyaluronic acid injection ultimately suitable for you? It depends on your condition, the severity of your symptoms, and other comorbid factors. Address your concerns with your pain specialist or doctor for a detailed and personalized review of a potential hyaluronic acid injection.