Arthrosamid Injections for Knee Osteoarthritis: Frequently Asked Questions

Arthrosamid is a non-biodegradable polyacrylamide hydrogel injected into the knee joint for osteoarthritis-related pain and stiffness; it integrates with the synovial tissue and can improve joint comfort and function in selected patients.

Arthrosamid may be suitable for patients with knee osteoarthritis who meet the following criteria:

• Persistent knee pain despite conservative management
• Radiological evidence of osteoarthritis
• Grade 2 or Grade 3 osteoarthritis (particularly suitable)
• Patients wishing to avoid or delay knee replacement surgery
• Patients who are not suitable candidates for surgery
• Selected patients with Grade 4 (bone-on-bone) osteoarthritis, where other options are limited and after careful discussion

Arthrosamid may not be appropriate in the following situations:

• Patients who have already undergone knee replacement surgery
• Active infection or skin infection around the knee
• Recent steroid injection into the knee joint within the last three months, due to increased infection risk
• Other medical conditions that make joint injection unsafe, as determined during specialist assessment

At Pain Spa, Arthrosamid injections are performed by Dr Krishna under real-time ultrasound guidance to improve accuracy and safety, confirm intra-articular placement, and tailor the procedure to the patient’s anatomy.

Yes. To minimise the risk of infection, we routinely prescribe prophylactic oral antibiotics prior to Arthrosamid injection; this involves a single pre-procedure dose of two different antibiotics taken 1–2 hours before the injection, with full instructions provided during consultation and a private prescription issued accordingly. Patients are asked to inform the clinic of any antibiotic allergies, particularly penicillin, so that an appropriate alternative can be prescribed.

In general, we prefer to treat one knee at a time rather than both knees on the same day in order to reduce infection risk; treating one side at a time also allows you to remain mobile if there is a temporary flare following injection.

Most patients tolerate the procedure well, but some experience temporary discomfort, fullness, or a flare of pain in the first few days to weeks; this is usually managed with simple analgesia and cold compresses, and you will be given clear aftercare guidance.

Improvement is typically gradual; many patients notice change from around 4–6 weeks, and maximum benefit can take up to 12 weeks.

Arthrosamid can provide long-lasting benefit in selected patients, with pain relief reported for up to three years.

You should not have a steroid injection into the same knee joint within three months of Arthrosamid injection; if you are considering surgical treatment, always inform your surgeon that you have had Arthrosamid injection as surgery may need to be delayed temporarily.

Yes, exercise and rehabilitation are an important part of treatment with Arthrosamid; the focus should be on strengthening the quadriceps muscles, with gradual mobilisation and progressive exercise as outlined in the rehabilitation guidance provided (https://arthrosamid.com/rehab).

Not all patients respond, and overall response rates are often quoted at around 70%; if Arthrosamid is not suitable or does not provide adequate relief, Pain Spa can discuss alternative options including physiotherapy-led rehabilitation, medication optimisation, genicular nerve blocks, and radiofrequency-based treatments.

To arrange an appointment or request further information, please contact Pain Spa at clinic@painspa.co.uk or via our website www.painspa.co.uk.