Hyaluronic acid viscosupplementation for osteoarthritis pain relief and improved mobility
What is osteoarthritis?
Osteoarthritis is a degenerative joint disease and the most common form of arthritis, affecting hundreds of millions of people worldwide. Incidence of the condition increases with age, but onset can happen at any age. Osteoarthritis is characterised by joint pain, stiffness and joint instability. Frequently referred to as “wear and tear” arthritis, osteoarthritis is caused by deterioration of the cartilage that covers the ends of your bones, creating friction in the joint during movement. Additionally, the synovial fluid that lubricates the joint becomes degraded, losing its lubricating and shock absorbing properties.1 As a result, the joint becomes painful and stiff, limiting mobility. The severity of joint pain can vary greatly and can affect any joint, but most often affects the knees, hands, lower back, neck, or hips. What is the typical course of treatment for osteoarthritis? Osteoarthritis treatment can include pharmacological and non-pharmacological approaches. For mild symptoms, conservative treatment approaches can be effective to alleviate the symptoms. These approaches include lifestyle adjustments such as exercising and maintaining a healthy weight. As the condition progresses, pharmacological treatments may be required to relieve symptoms. Commonly used options include painkillers that act to reduce inflammation, such as oral non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids. These treatments provide rapid but short-lived pain relief and are associated with frequent side effects, making them inappropriate for prolonged use. Oral NSAIDs increase the risk of adverse events such as gastrointestinal bleeding, kidney injury, heart attack and stroke.2 Frequent corticosteroid injections are not recommended as they can accelerate osteoarthritis progression, weaken the bone, disrupt blood flow, and increase the risk of fracture.3 If conservative osteoarthritis treatment is no longer effective at relieving pain, surgery may be considered to replace the joint as a last resort. For these patients, viscosupplementation with hyaluronic acid can be an effective approach to reduce joint pain, improve joint function, and delay the need for surgery.
What is the role of hyaluronic acid in the joint?
Hyaluronic acid (also called hyaluronan or sodium hyaluronate) is a biopolymer that occurs naturally in the synovial fluid in the space around your joints. Hyaluronic acid helps to maintain the viscosity of synovial fluid and is important for reducing friction in the joint. It also acts as a shock absorber, providing cushioning for the joint.4 In patients with osteoarthritis, the quality of synovial fluid is degraded due to a lower concentration of hyaluronic acid. This can contribute to greater friction and cartilage damage. Injections of hyaluronic acid into the joint (referred to as viscosupplementation) can boost the body’s natural supply, reducing friction in the joint, absorbing impacts, facilitating movement, and reducing pain. By restoring the natural properties of the synovial fluid, viscosupplementation aims to provide protection against cartilage damage.4
How effective is hyaluronic acid injection for treating osteoarthritis?
Pain relief following hyaluronic acid treatment can take 1-4 weeks to take effect,5 and can last upwards of 6 months. As a result, patients can benefit from long periods of symptom relief between treatments. The treatment has high levels of patient satisfaction and a high success rate, with 80% of patients responding well to hyaluronic acid treatment.6,7 Viscosupplementation has been proven to be effective for:
- Prolonging time until joint replacement surgery8
- Improving joint function5,6 and mobility8
- Reducing pain6,10 and reducing use of painkillers9,11,12
Hyaluronic acid viscosupplementation is suitable for both large and small joints but is most commonly used to treat osteoarthritis of the knee.
Are there any side effects associated with hyaluronic acid injection?
Hyaluronic acid is well tolerated and can be used safely in patients with comorbidities. Hyaluronic acid is a molecule that is naturally produced by the human body, and is present in the skin, the joints and the tendons. As a result, adverse reactions to hyaluronic acid are rare. The most common side effects are localised inflammation or swelling, which subside within a short period of time.6,7,11 Biofermented hyaluronic acid of non-animal origin has a better safety profile than hyaluronic acid derived from animal products. Hyaluronic acid from animal sources, such as rooster combs, comes with a higher risk of adverse reactions such as swelling and inflammation.13
How is the treatment given?
Hyaluronic acid viscosupplementation is given as an intra-articular injection — meaning that it is injected directly into the joint. The treatment should only be administered by a physician who is trained and experienced in intra-articular injections. The treatment is most effective when the injection is guided by ultrasound, which enables precise targeting of the injection. Depending on the choice of injection, it may be one individual shot, or a course of up to five injections.