Injection Therapy

Hyaluronic Acid Injection

A gel-like joint injection designed to supplement natural joint lubrication and support mobility in select patients.

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What is a Hyaluronic Acid Injection?

A hyaluronic acid injection (also known as viscosupplementation) involves injecting a gel-like substance directly into the knee joint. Hyaluronic acid is a naturally occurring component of synovial fluid that acts as a lubricant and shock absorber. In degenerative joint disease, the concentration of natural hyaluronic acid decreases, and these injections aim to supplement joint lubrication.

Procedure & Aftercare Details

Hyaluronic Acid Injection Explanation

1. Joint Anatomy Target

AnatomyClinical Approved

Hyaluronic Acid Injection Target

Viscosupplementation gel lubricating and shock-absorbing in the joint space.

2. Injection Needle Path

Needle PathClinical Approved

Hyaluronic Acid Needle Access Path

Needle path for viscosupplementation injection under ultrasound guidance.

This outpatient procedure is conducted under strict sterile conditions:

1Clinical assessment and review of diagnostic imaging to verify suitability.

2Informed consent discussion outlining potential benefits, risks, and alternatives.

3Thorough cleansing of the skin with an antiseptic solution under sterile conditions.

4Aspiration of any excess joint fluid if present, followed by injection of the hyaluronic acid gel.

5Application of a clean dressing to the puncture site.

6Review of rest and activity instructions before discharging the patient.

Clinical AccuracyUltrasound-Guided Injections

We highly recommend executing injections under real-time ultrasound guidance to ensure precise placement within the joint space, maximizing therapeutic safety and efficacy.

Learn About Guidance →

Clinical Characteristics Summary

Onset of Action2-4 weeks

Typical Duration6-9 months

Primary MechanismJoint lubrication & viscosupplementation

Main IndicationMild-to-moderate knee osteoarthritis

This information is for general patient education and does not replace an individual clinical assessment.

How does it work?

Viscosupplementation works by restoring the lubricating properties of the joint fluid. By increasing viscosity within the synovial cavity, it aims to reduce friction between worn cartilage surfaces during weight-bearing movements. The evidence surrounding the long-term clinical benefits of these injections continues to evolve, and they are considered on a case-by-case basis.

Who is this suitable for?

Patients Who May Be Considered

Patients with mild-to-moderate knee osteoarthritis who have not obtained relief from simple analgesics.
Individuals seeking non-pharmacological options for managing knee discomfort.
Selected patients where corticosteroid injections are contraindicated or have not provided satisfactory relief.
Patients who wish to support active rehabilitation through improved joint lubrication.

Who May Not Be Suitable

Active skin or joint infections in or around the knee.
Known hypersensitivity or allergy to hyaluronic acid products or components.
Severe end-stage osteoarthritis where the joint space has completely collapsed.
Significant inflammatory joint flare-ups (where fluid buildup should be addressed first).

Potential Benefits & Risks

Potential Benefits

Aims to supplement joint lubrication and shock absorption.
May help reduce friction and joint discomfort during movement in select patients.
Potential to support active rehabilitation and daily function.
Avoids the systemic side effects associated with oral anti-inflammatory medications.

Risks & Limitations

Clinical evidence regarding efficacy remains variable, and not all patients experience improvement.
Suitability depends on a comprehensive clinical assessment rather than diagnostic severity alone.
There is no evidence that hyaluronic acid regenerates worn cartilage or reverses osteoarthritis.
Potential for temporary local swelling, warmth, or pain following the injection.
Very small risk of post-injection joint infection.

What happens during the procedure?

Knee injections are outpatient procedures completed in our sterile clinical rooms. The step-by-step process is detailed in the interactive guide above, including:

1. Preparation & CleaningJoint positioning, skin disinfection, and local anaesthetic.

2. Needle InsertionPrecise injection, often under ultrasound guidance.

3. Dressing & MonitoringSterile dressing applied and post-procedure check.

Needle placement may be performed under real-time imaging guidance depending on clinical indication.Learn about ultrasound-guided knee injections →

After the injection

Aftercare is focused on protecting the joint and monitoring for rare complications. Guidelines are outlined in the interactive tabs above. Remember to rest the joint for the first 48 hours and avoid unaccustomed heavy loads.

Frequently Asked Questions

No. Hyaluronic acid injections do not rebuild, regenerate, or repair worn cartilage. They are designed to supplement joint lubrication and cushion the joint surfaces to help manage symptoms, rather than change the underlying joint structure.

The appointment typically takes 15 to 30 minutes, allowing for clinical assessment, sterile site preparation, administration of the injection, and review of post-procedure instructions.

Yes, in most cases, patients can drive home. However, if you experience localized discomfort or stiffness immediately after the injection, it is recommended to rest or arrange alternative transport for comfort.

You should avoid strenuous or high-impact exercise (such as running, heavy lifting, or sports) for 48 hours after the injection. Light walking and normal daily activities are generally fine if comfortable.

Viscosupplementation is typically administered as a single injection or a short series, depending on the specific product. Repeat injections may be considered after 6 months if clinically indicated and if the patient obtained benefit from the initial treatment.

Most patients describe the injection as a pressure sensation rather than severe pain. The procedure is performed under sterile conditions and local anaesthetic may be used to minimize skin discomfort.

Yes. An up-to-date X-ray or MRI scan is required to evaluate the degree of cartilage wear and ensure that viscosupplementation is a suitable option for your specific joint anatomy.

In some patients with mild-to-moderate osteoarthritis, supplementing joint lubrication may help manage symptoms and support daily function, which might defer the need for surgery. However, it does not stop the wear process.

Which injection may be appropriate?

Choosing an injection therapy requires an individualized clinical assessment. The choice depends upon several factors, including:

Verified clinical diagnosis
Type and severity of symptoms
Diagnostic imaging findings (X-ray, MRI, Ultrasound)
Patient activity levels and functional goals
Previous conservative treatments attempted
Individual medical history, medications, and allergies
Potential clinical risks versus patient-specific benefits
Available non-injection treatment alternatives

⚠️ Only an individual consultation with our consultant orthopaedic surgeon can determine whether a knee injection is clinically appropriate for your condition.

Schedule a Clinical Consultation

To evaluate your knee symptoms and discuss whether an injection therapy is indicated, arrange a specialist consultation.

Call Clinic Book Assessment

Clinically Reviewed

Mr Ricardo J Pacheco (GMC 4145976)Consultant Trauma & Orthopaedic Surgeon

Last reviewed: 29 July 2026

Evidence & References

NICE guidelines on osteoarthritis management (reviewing viscosupplementation evidence).
International Society for Osteoarthritis Research (OARSI) guidelines and publications.
Clinical trials evaluating intra-articular hyaluronic acid formulations for knee pain.
Role and Effectiveness of Intra-articular Injection ... - PMC - NIH (pmc.ncbi.nlm.nih.gov)
Expert consensus on hyaluronic acid injections for knee osteoarthritis (link.springer.com)
Review article Viscosupplementation: Techniques, indications, results (sciencedirect.com)
Expert consensus on hyaluronic acid injections for knee osteoarthritis (pubmed.ncbi.nlm.nih.gov)

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Medical Disclaimer

This website provides educational and general information about knee symptoms, conditions, and treatments. The content is for informational purposes only and does not constitute medical advice, diagnosis, or a treatment plan. It should not be used as a substitute for a professional consultation, examination, or clinical decision-making by a qualified orthopaedic specialist.

If you are experiencing symptoms or are concerned about a knee problem, please arrange a clinical consultation. If you have urgent symptoms, severe pain, or are unable to put weight on your leg, please read our urgent advice guidance or contact emergency services immediately (dial 999 or NHS 111).