Knee Injections

What are knee injections?

Knee injections are non-surgical treatments used to reduce pain, inflammation and stiffness in patients with knee osteoarthritis or inflammatory arthritis. They are an important part of the non-surgical management pathway and can significantly improve quality of life, delay the need for surgery, and help patients manage symptoms between other treatments. All injections are performed in a dedicated procedure room using strict aseptic technique.

1. Steroid and local anaesthetic injection

A corticosteroid combined with local anaesthetic is the most widely used injection for painful, inflamed knee arthritis and is the first-line option in patients experiencing an acute flare-up.

• How it works: the steroid reduces synovial inflammation — the primary driver of pain in arthritic flares.
• The local anaesthetic provides immediate relief and confirms the knee as the source of pain.
• Duration: typically 4–12 weeks; some patients benefit for considerably longer.
• Suitable for: acute flares, mild to moderate osteoarthritis, or as a temporary measure before surgery.

2. Hyaluronic acid injection — Durolane

For patients with moderate or early arthritic changes who are not yet ready for knee replacement and in whom steroid injections have not provided sustained relief, I prefer to offer Durolane hyaluronic acid.

• Durolane is a single-injection, non-animal stabilised hyaluronic acid (NASHA) product.
• Works primarily as an anti-inflammatory agent absorbed into the synovium — not merely as a lubricant.
• Pain relief shown in studies up to 6 months and beyond, often outlasting steroid injections.
• Single injection — practical convenience compared with multi-dose courses.

3. Arthrosamid® — polyacrylamide hydrogel injection

Arthrosamid is an innovative treatment for knee osteoarthritis and a step beyond conventional injection therapies. It is a non-biodegradable polyacrylamide hydrogel (iPAAG) — a soft, flexible gel injected directly into the knee joint that integrates permanently into the synovial lining, reducing synovial irritation and the inflammatory cycle that drives ongoing pain.

• Acts as an anti-inflammatory agent absorbed into the synovium and remains permanently in the joint.
• Classified as an implant — a single dose of oral antibiotics is required before the procedure.
• Duration: clinical studies show relief lasting up to 2–3 years or more from a single injection.
• Over 70% of patients achieve significant pain reduction and improved mobility, with results building over the first 4–12 weeks.
• Suitable for: mild to moderate knee osteoarthritis where steroid injections have provided insufficient relief.
• Not suitable for: severe (bone-on-bone) arthritis, inflammatory arthritis, or active infection.
• Procedure: ultrasound-guided in a procedure room under local anaesthetic; takes 20–30 minutes.

My approach

• All injections in a dedicated procedure room under strict aseptic conditions
• Steroid + local anaesthetic for acute flares and initial treatment
• Durolane hyaluronic acid where steroid relief is insufficient or short-lived in moderate arthritis
• Arthrosamid for persistent symptoms with inadequate response to other injections — longer-lasting relief from a single injection
• Antibiotic prophylaxis required for Arthrosamid
• Available at: Meriden Nuffield Health Hospital and University Hospitals Coventry & Warwickshire

Risks

• Post-injection flare (24–48 hours) — most common with steroid injections
• Infection — minimised by strict sterile technique
• Skin and soft tissue changes with repeated steroid injections
• Repeated high-dose steroid injections may accelerate cartilage damage; frequency carefully managed
• Arthrosamid: transient swelling and discomfort at the injection site; no significant long-term adverse effects reported in clinical studies