Arthrosamid Injections for Severe Knee Osteoarthritis: A Case Series from Pain Spa

Background: Knee Osteoarthritis and the Need for Non-Surgical Options

Knee osteoarthritis is a common and progressive condition that can lead to severe pain, stiffness, reduced mobility, and significant impairment in quality of life, particularly in older adults and in patients with long-standing joint disease.

While knee replacement surgery can be effective for some patients, many individuals either wish to avoid surgery, are not medically suitable for joint replacement, or prefer to explore less invasive options that may provide meaningful and sustained pain relief.

Case Series Overview

This article describes a series of five Arthrosamid injections performed in four patients with moderate to severe knee osteoarthritis treated at Pain Spa.

One patient underwent bilateral knee Arthrosamid injections performed on separate occasions, while the remaining patients were treated unilaterally, based on symptom severity and functional limitation.

Patient Selection and Clinical Context

All patients in this case series had long-standing knee pain due to osteoarthritis, with imaging demonstrating moderate to severe degenerative changes, including advanced compartmental disease in some cases.

These patients had either failed conservative management, experienced limited or short-lived benefit from previous injection treatments, or wished to avoid or delay knee replacement surgery.

What Is Arthrosamid?

Arthrosamid is a non-biodegradable polyacrylamide hydrogel designed for intra-articular injection into the knee joint and is described in more detail on our Arthrosamid injection for knee osteoarthritis page.

Unlike steroid injections or viscosupplementation, Arthrosamid integrates permanently with the synovial tissue, leading to improved joint cushioning, reduced stiffness, and long-term modulation of pain and function.

Procedure Technique

All Arthrosamid injections in this series were performed under real-time ultrasound guidance by Dr Krishna, ensuring accurate intra-articular placement and maximising procedural safety.

Ultrasound guidance allows visualisation of joint anatomy, confirmation of needle position, avoidance of surrounding structures, and improved consistency of outcomes compared with landmark-based techniques.

Clinical Outcomes

Across this case series, patients reported significant improvement in knee pain, walking tolerance, and functional ability following Arthrosamid injection.

Improvements typically developed gradually over several weeks, with continued benefit noted at follow-up, allowing patients to increase activity levels and reduce reliance on regular analgesic medication.

Duration of Benefit

One of the key advantages of Arthrosamid is the potential for long-lasting pain relief of up to three years, which is considerably longer than most conventional injection treatments used for severe knee osteoarthritis.

Limitations of Other Injection Treatments

Steroid injections may provide short-term relief but are typically limited to weeks or a few months, with concerns regarding cartilage damage, infection risk, and systemic side effects if repeated frequently.

Similarly, viscosupplementation can offer modest benefit in selected patients but often provides limited or unpredictable relief in advanced osteoarthritis.

Arthrosamid and Knee Replacement Surgery

Arthrosamid is particularly suitable for patients who wish to avoid knee replacement surgery or are not suitable surgical candidates.

This treatment is not suitable for patients who have already undergone knee replacement surgery, as it is designed for native knee joints.

Options for Patients with Knee Replacements

For patients with persistent pain following knee replacement, Pain Spa offers alternative interventional options, including genicular nerve blocks and cooled radiofrequency treatment of the genicular nerves, which can help manage ongoing pain without further surgery.

Expertise at Pain Spa

All Arthrosamid injections at Pain Spa are performed by Dr Krishna, a Consultant in Pain Medicine with extensive experience in ultrasound-guided joint injections and advanced interventional pain procedures, ensuring high standards of accuracy, safety, and patient care.

Important Considerations and Limitations

While Arthrosamid can provide substantial and long-lasting pain relief, it is important to recognise that not all patients will respond, and current evidence suggests that approximately 70% of patients experience meaningful benefit, while others may have limited or no improvement.

Summary

This case series demonstrates that Arthrosamid injection is a valuable non-surgical treatment option for selected patients with severe knee osteoarthritis, offering the potential for long-lasting pain relief, improved function, and reduced need for surgery when delivered by an experienced specialist under ultrasound guidance.