Hyaluronic Acid Injection for Knee Joint

Knee pain is one of the most common orthopaedic complaints in middle-aged and elderly individuals. A major cause of this pain is knee osteoarthritis, a degenerative condition in which the smooth cartilage lining of the knee gradually wears out. 

Patients often experience pain while walking, climbing stairs, squatting, or getting up from a chair. Stiffness, swelling, and reduced mobility may also occur.

While physiotherapy, weight management, and medications help most of these patients, some continue to have persistent symptoms. 

In such cases, hyaluronic acid injections can be considered as a good non-surgical treatment option.

H.A. injection for knee joint

What is Hyaluronic Acid (H.A.)?

Hyaluronic acid is a naturally occurring substance present inside the knee joint (synovial) fluid. It acts like a lubricant and shock absorber, helping the joint move smoothly. 

In osteoarthritis, both the quantity and quality of natural hyaluronic acid reduce, leading to increased friction, inflammation, and pain.

Hyaluronic acid injections, also called viscosupplementation injections, aim to restore lubrication within the joint and improve knee function.

How do these injections work?

The injected hyaluronic acid improves the viscosity and elasticity of joint fluid. This helps by:

• Reducing friction between joint surfaces

• Improving shock absorption

• Decreasing inflammation inside the knee

• Improving joint movement

• Reducing pain during daily activities

Some studies also suggest that hyaluronic acid may stimulate the knee to produce more natural joint fluid over time.

Who should consider taking Hyaluronic Acid injections?

These injections are most useful in patients with mild to moderate knee osteoarthritis. They are often considered when:

• Pain persists despite supervised physiotherapy and medications

• Patients want to delay knee replacement surgery for a few months

• Patients who wish to remain active with less discomfort

Stages of Knee Osteoarthritis

Patients with advanced end-stage ‘bone-on-bone’ arthritis may not experience a significant benefit, although selected patients can still obtain some temporary relief.

What is the procedure of injection?

The procedure is performed in the outpatient (OPD) clinic and takes only a few minutes.

The area around the knee joint is cleaned thoroughly to maintain sterility. Some local anaesthesia is given to avoid pain.

The hyaluronic acid is then injected into the joint taking all sterile precautions.

Most patients tolerate the procedure well. Mild discomfort during injection may occur but it is  temporary.

When does the relief start?

Unlike steroid injections, hyaluronic acid injections do not usually provide immediate pain relief. Improvement is often gradual and begins after 2 to 6 weeks. The benefit can last for several months in suitable patients.

Some patients experience significant reduction in pain and improved walking ability, while others may notice only mild improvement. Response varies depending on the severity of arthritis, body weight, activity level, and overall knee condition.

Advantages of Hyaluronic Acid injections

1. Non-Surgical Treatment with knee injection

These injections offer a minimally invasive option for patients who are not yet ready for surgery.

2. Reduced Dependence on Painkillers

Patients require fewer oral pain medications after successful treatment, hence avoiding side-effects of the tablets

3. Improved Mobility

Many patients report easier walking, climbing stairs, and performing daily activities.

4. Can Delay Surgery

In selected patients, symptom relief is long lasting and helps postpone knee replacement surgery by a few months.

5. Generally Safe

When performed properly under sterile precautions, complications are uncommon.

Limitations of Hyaluronic Acid injections

• Although beneficial for many patients, these injections are not a cure for arthritis. 

• They cannot regenerate completely worn-out cartilage or reverse severe deformity.

• Certain patients may not respond adequately. Results are generally better in earlier stages of arthritis compared to advanced disease.

• Even when effective, they offer only a temporary solution and recurrence of knee pain is eminent. 

What are the side effects and risks involved?

Hyaluronic acid injections are generally safe, but minor side effects can occur, including:

• Temporary pain at injection site

• Mild swelling

• Warmth around the knee

• Stiffness or heaviness for 1-2 days

Applying ice and resting the knee for a short period usually helps.

Rare complications include:

• Joint infection

• Allergic reaction

• Severe inflammatory response

Patients should seek immediate help of the doctor if they develop fever, severe swelling, redness, or worsening pain after injection.

How are Hyaluronic Acid and Steroid Injections different?

Both injections are used for knee arthritis but work very differently.

Steroid injections mainly reduce inflammation and often provide faster, short-term and short lasting relief. However, repeated steroid injections tend to have more side effects.

Hyaluronic acid injections focus more on improving joint lubrication and may provide longer-lasting functional improvement in selected patients, though relief develops more gradually.

Doctors choose one over the other depending on the patient’s symptoms, age, medical conditions, and stage of arthritis. In general, HA injections are much safer than steroid injections.

Are H.A. injections really effective?

Scientific studies show mixed but encouraging results. Many patients report significant pain reduction and better knee function, especially in mild to moderate arthritis.

However, not every patient experiences dramatic improvement. Proper patient selection is extremely important. Patients with severe deformity, major instability, or advanced cartilage loss may eventually require surgical treatment.

Importance of physiotherapy & exercises

Non-weight bearing exercises are good for knees

• Hyaluronic acid injections work best when combined with strengthening exercises. Weak thigh muscles increase stress on the knee joint.

• Physiotherapy helps improve muscle support, balance, and walking mechanics.

• Exercises focusing on quadriceps strengthening, hamstring stretching, and low-impact activities such as cycling or swimming are particularly useful.

Lifestyle measures that improve the results

Patients can improve the outcomes by:

• Maintaining healthy body weight

• Avoiding squatting or stair climbing

• Using comfortable supportive footwear

• Staying physically active

• Following prescribed exercise program

Even a small amount of weight loss significantly reduces pressure on the knee joint.

So what do we know?

• Hyaluronic acid injections are a useful non-surgical treatment option for patients with knee osteoarthritis, particularly in the early to moderate stages. 

• Although it is not a magic wand for arthritis, it provides significant symptom relief and helps delay surgery in selected individuals.

• The success of treatment depends on proper patient selection and combining injections with physiotherapy, weight management, and lifestyle changes. 

• Consultation with an orthopaedic specialist will help you know whether you are the right candidate for hyaluronic acid injections or not.

If you are suffering from constant knee pain or have been diagnosed with knee osteoarthritis, consult Dr. Ajinkya Achalare at ArthroSports Orthopaedic Clinic at Dadar, Mumbai for expert advice and compassionate care.