Hydrogel Injections for Knee Pain: What to Expect

Hydrogel injections offer a non-surgical option for some people living with knee osteoarthritis and persistent joint pain. If you are considering treatment, understanding how the procedure works, what happens afterwards and when results may develop can help you make a more informed decision.

What Are Hydrogel Injections?

Hydrogel injections are designed to help manage symptoms associated with knee osteoarthritis. One example is Arthrosamid®, an injectable polyacrylamide hydrogel that is placed directly into the knee joint.

Unlike some injectable treatments that are gradually absorbed, Arthrosamid® is a non-biodegradable hydrogel implant. It is intended to integrate with the synovial tissue lining the joint and help reduce pain associated with knee osteoarthritis.

Hydrogel injections do not reverse osteoarthritis or regrow damaged cartilage. Instead, their purpose is to reduce symptoms and improve knee function in appropriately selected patients.

A specialist assessment is therefore an important first step. Your clinician will review your symptoms, medical history, previous treatments and the condition of your knee before deciding whether this type of treatment may be suitable.

What Happens During the Procedure?

Hydrogel injections are generally performed as an outpatient procedure, which means you can usually return home the same day.

For Arthrosamid® treatment, a local anaesthetic is used to numb the area around the knee. Antibiotics are also given beforehand to reduce the risk of infection. The knee is cleaned carefully before the hydrogel is injected into the synovial cavity of the joint, sometimes with ultrasound guidance.

The procedure itself is relatively straightforward and does not involve open surgery. Once the injection has been completed, the needle is removed and a small dressing is placed over the injection site.

You may feel pressure or mild discomfort during parts of the procedure, although the local anaesthetic should help minimise pain.

Your clinician should also explain what to expect before treatment, including possible risks, aftercare instructions and any temporary changes you may need to make to your usual activities.

What Should You Expect Afterwards?

Some people experience temporary discomfort after hydrogel injections. Reported side effects following Arthrosamid® treatment include joint pain and a feeling of swelling, which have generally been mild and temporary in clinical studies.

You should follow the specific aftercare advice provided by your treating clinician. This may include temporarily modifying strenuous exercise or other activities while the knee settles following the procedure.

It is also important not to judge the outcome immediately. Although some patients may notice changes relatively quickly, maximum benefit can take several weeks to develop. Arthrosamid patient information states that improvement may begin within the first few weeks, while the full effect can take up to around 12 weeks.

Everyone responds differently, so improvement cannot be guaranteed. Some patients may experience meaningful pain reduction, while others may have a more limited response.

Contact your treating clinician if you develop unusual or worsening symptoms following treatment. Infection is considered a rare potential complication, but symptoms suggesting an infection require prompt medical assessment.

Are Hydrogel Injections Right for Everyone?

Hydrogel injections are not suitable for every person with knee pain.

Arthrosamid®, for example, is intended for adults with symptomatic knee osteoarthritis. Certain circumstances may prevent treatment, including an active infection around the knee, an infected or severely inflamed joint, previous knee replacement or some recent procedures involving the affected knee.

Your clinician should also consider your general health, existing medical conditions and previous injectable treatments.

This is why an accurate diagnosis matters. Knee pain can have several causes, and treatment should address the underlying problem rather than simply the symptom.

For some patients, conservative measures such as physiotherapy, exercise and pain management may remain appropriate. Others may want to explore injection-based treatments before considering more invasive options.

Understand Your Treatment Options

Hydrogel injections can provide a non-surgical treatment option for selected people with knee osteoarthritis. The procedure is typically completed during a single outpatient visit, but results develop gradually and individual responses can vary.

The best way to determine whether treatment is appropriate is through a specialist assessment of your knee, symptoms and previous care.

At Regenesis, we focus on regenerative and non-surgical orthopaedic treatment options for joint conditions. If persistent knee pain is affecting your mobility or quality of life, explore our treatment information or contact our team to discuss which options may be suitable for you.