What Are Hyaluronic Acid Knee Injections?

Hyaluronic acid (HA) is a naturally occurring substance found in the synovial fluid of healthy joints. It provides lubrication and cushioning to protect cartilage and reduce friction. In people with knee osteoarthritis, HA levels decline, leading to stiffness, inflammation and pain.

By replenishing this lost HA, hyaluronic acid injections help improve lubrication, reduce inflammation and relieve pain—making it easier to move comfortably again.

Comparing the Main Hyaluronic Acid Knee Injections

Ostenil (Ostenil Plus / Ostenil Mini)

• Composition: Purified sodium hyaluronate; Ostenil Plus also includes mannitol for added stability.
• How it works: Restores natural joint lubrication and may encourage the body’s own HA production.
• Treatment course: Either three weekly injections (Ostenil) or a single injection (Ostenil Plus).
• Ideal for: Mild to moderate knee osteoarthritis where gradual, long-term relief is desired without steroids.
• Expected results: Relief builds gradually and lasts up to six months.

Monovisc

• Composition: High-molecular-weight, non–cross-linked hyaluronic acid closely matching natural joint fluid.
• How it works: Provides cushioning and lubrication to reduce pain and stiffness.
• Treatment course: Single injection for convenience.
• Ideal for: Patients seeking a one-off, steroid-free option for mild to moderate OA.
• Expected results: Gradual relief developing over several weeks, lasting up to six months.

Cingal

• Composition: A combination of highly purified HA and a corticosteroid (triamcinolone hexacetonide).
• How it works: Delivers rapid anti-inflammatory effects and sustained joint lubrication.
• Treatment course: Typically a single injection.
• Ideal for: Those needing quick relief from knee pain and swelling alongside longer-term benefits.
• Expected results: Noticeable pain reduction within days, lasting up to six months.

Who Can Benefit from Hyaluronic Acid Knee Injections?

• People with mild to moderate knee osteoarthritis
• Patients experiencing persistent knee pain and stiffness despite physiotherapy or medication
• Those looking for a non-surgical knee pain relief option
• Individuals who cannot tolerate oral pain medications such as NSAIDs

While hyaluronic acid injections can be highly effective, they are less suitable for advanced “bone-on-bone” arthritis, where cartilage damage is severe.

What to Expect During and After the Procedure

During the Injection

The knee area is cleaned and may be numbed with a local anaesthetic. The clinician then injects the HA directly into the joint—ideally using ultrasound guidance for precision.

After the Injection

• Mild soreness or swelling may occur and usually subsides within 24–48 hours.
• Avoid heavy exercise for one to two days after treatment.
• Pain relief typically develops gradually, with results lasting up to six months.

Side Effects

Minor side effects such as temporary redness or swelling are uncommon and short-lived. Serious reactions are rare, but contact your clinician if you experience increased pain, redness or warmth around the knee.

Why Guided Knee Injections Are Recommended

• Accuracy: Ensures the HA is placed precisely inside the joint capsule.
• Safety: Minimises risk to surrounding nerves or blood vessels.
• Better outcomes: Proper placement improves comfort and prolongs results.

For best results, always choose a qualified clinician offering ultrasound-guided knee injections.

Key Takeaway

Hyaluronic acid knee injections such as Ostenil, Monovisc and Cingal provide safe, minimally invasive relief for knee osteoarthritis. Choosing the right product depends on your symptoms, lifestyle and how quickly you want results. Discuss with your GP or joint specialist whether this treatment could help you regain mobility and reduce pain.

Book a consultation or contact our clinic to learn more about hyaluronic acid knee injections in the UK.

Frequently Asked Questions