Hyaluronic acid has been used successfully for years to treat osteoarthritis, particularly knee osteoarthritis. This substance, a natural component of the body found in synovial fluid, can help lubricate the joints and improve their mobility, thereby relieving pain and increasing quality of life. Studies show that hyaluronic acid injections often have a positive effect, especially in dry forms of osteoarthritis, meaning those without inflammation or joint effusion. However, the success rate is usually lower in inflammatory osteoarthritis, as hyaluronic acid is not as effective in these cases.

In the knee joint, hyaluronic acid can alleviate pain and potentially slow cartilage degradation by acting as a kind of "lubricant." A distinction is made between low-molecular-weight and high-molecular-weight hyaluronic acid, which remain in the joint for different lengths of time and have different effects. Low-molecular-weight hyaluronic acid has the potential to penetrate the joint more quickly and offer rapid relief in mild to moderate cases of osteoarthritis, while high-molecular-weight variants tend to have a longer-lasting effect but are less readily incorporated into the cartilage.

Hyaluronic acid is also used for the hip joint, although its application there is associated with somewhat higher risks. Due to the location and access of the injection into the hip, complications such as injury to nerves or blood vessels in the groin area can occur. Therefore, careful consideration is often given to whether hyaluronic acid is actually the appropriate therapy.

When using hyaluronic acid to treat osteoarthritis, the molecular weight of the substance plays a crucial role in the effectiveness and longevity of the treatment. Hyaluronic acids are available in low and high molecular weights, and both variants have different properties and application advantages.

Differences in the molecular weight of hyaluronic acid

• Low molecular weight hyaluronic acid has a lower molecular weight and can penetrate joint tissue more quickly. It usually has a short-term effect and is preferred for mild to moderate osteoarthritis. Because it is broken down more quickly, multiple injections are necessary to maintain the effect over a longer period. Its small size also means that it distributes well in the tissue, but often offers less mechanical stability.
• High-molecular-weight hyaluronic acid, due to its larger molecular structure, is more viscous and remains in the joint longer. This variant is frequently used in more advanced cases of osteoarthritis because it can better cushion the joint and possesses anti-inflammatory properties. High-molecular-weight hyaluronic acids often offer longer-lasting pain relief, but the effect is delayed and usually occurs after several weeks.

Dosage and course of therapy: The hyaluronic acid treatment

A typical hyaluronic acid therapy for knee osteoarthritis often involves a series of injections over several weeks. The classic hyaluronic acid course with five injections is a common method, in which a dose is injected into the affected joint each week for five weeks. This gradual administration ensures that the hyaluronic acid is optimally distributed and that the gel's viscoelastic properties are fully effective within the joint.

The effect of this treatment varies: patients often report a gradual improvement in their symptoms after about two to three injections. This stepwise approach is intended to gradually relieve the joint and promote natural regeneration, while lubricating the joint space and reducing pain

Frequency of application of hyaluronic acid

The dosage can vary depending on the type of hyaluronic acid and the manufacturer. There are low-dose preparations that require more frequent injections and high-dose products that are administered at longer intervals. The decision regarding dosage and injection frequency depends on the course of the disease, the condition of the joint, and the patient's response to treatment. High-molecular-weight hyaluronic acids often require fewer sessions because they remain in the joint longer.

Hyaluronic acid for osteoarthritis: What is it and how does it work?

Hyaluronic acid is a natural component of cartilage and synovial fluid and plays a key role as a lubricant in the joints. In osteoarthritis, a degenerative joint disease, the synovial fluid is often less viscous and the cartilage is worn down, which impairs mobility and causes pain. Treatment involves injecting hyaluronic acid into the affected joint to improve lubrication and provide some pain relief. The effects often only become apparent after several weeks and can vary in intensity from patient to patient.

When does hyaluronic acid help with knee osteoarthritis?

Hyaluronic acid is frequently used to treat knee osteoarthritis and can, in certain cases, improve mobility and alleviate pain, particularly in "dry" osteoarthritis, where inflammation and swelling in the joint are not the primary symptoms. Many patients with mild to moderate osteoarthritis experience a significant improvement in symptoms, making hyaluronic acid a popular adjunctive treatment option. However, in advanced osteoarthritis or inflammatory forms with severe irritation and joint effusion, the benefits are often less pronounced, as the inflammatory process can impair its effectiveness.

Hyaluronic acid in hip osteoarthritis: Risks and benefits

Hyaluronic acid can also be used in the hip joint; however, the injection is technically more challenging because nerves and blood vessels in the groin run in close proximity. Due to the higher risk of injury, the injection must be performed under strict medical supervision. Moderate success can be observed in non-inflammatory forms of hip osteoarthritis, but the effect often falls short of that seen in knee osteoarthritis. Furthermore, some experts point out that its use in hip osteoarthritis is less researched and therefore more controversial than in the knee.

Hyaluronic acid: Risks, side effects and controversies

Although hyaluronic acid injections are generally well-tolerated, side effects such as pain, swelling, redness, or, in rare cases, allergic reactions can occur. In the event of an adverse reaction, the treatment may be discontinued. Studies show that only about half of patients experience a benefit and must bear the treatment costs themselves, as statutory health insurance companies in Germany consider hyaluronic acid injections to be an individual health service (IGeL).

Scientific viewpoint on the effectiveness of hyaluronic acid

Scientific opinion on the effectiveness of hyaluronic acid is divided. While some studies show that the acid brings about moderate improvement in non-inflammatory osteoarthritis, organizations such as Stiftung Warentest point out that the effectiveness of the treatment is controversial. Most positive effects appear to be temporary, and long-term studies on pain relief and functional improvement are still lacking. Therefore, statutory health insurance companies generally do not cover the costs of hyaluronic acid treatment.

Conclusion: When is hyaluronic acid beneficial?

Hyaluronic acid injections are a possible treatment option, depending on the severity of the osteoarthritis, the molecular weight, and the individual patient's response. While a course of five hyaluronic acid injections can support long-term lubrication and regeneration of the joint, other dosages and molecular weights are also effective. For many patients, a thorough consultation is crucial to choosing the most suitable form of therapy.

Hyaluronic acid can be an option for osteoarthritis, especially for patients with dry knee osteoarthritis and low levels of inflammation. However, expectations are rather low for hip osteoarthritis and advanced joint destruction. Each patient should individually and in consultation with an endoprosthetic specialist to consider whether such treatment is appropriate and what alternatives are available.