Viscosupplementation Treatment for Knee Arthritis

Introduction

Knee arthritis starts to appear when the protective cartilage within the joint deteriorates, which can result in stiffness and discomfort during specific movements. Osteoarthritis is characterized by the progressive breakdown of cartilage due to aging and stands as the most common type of arthritis affecting the knee. Also, autoimmune disorders and injuries can contribute to cartilage deterioration in this joint. The cartilage damage linked with arthritis is irreversible. Multiple nonsurgical and surgical interventions exist to alleviate pain, improve joint mobility, and enhance the overall well-being of individuals with knee arthritis. These treatments offer approaches for managing the symptoms and restoring functionality. Therefore, there is a significant improvement in the quality of life for those affected by this debilitating condition.

What Are the Symptoms of Knee Arthritis?

The following are the symptoms of knee arthritis:

1. Knee pain aggravated by specific movements and exercises, notably prolonged walking or standing.

2. Stiffness in the knee joint, reducing the ability to flex and extend the knee.

3. Episodes of catching and locking in the knee, associated with roughened cartilage, hinder smooth joint movements.

4. Crepitus, characterized by audible cracking, clicking, crunching, or snapping sounds arising from the affected joint during movement.

5. Knee weakness from reduced activity results in muscle atrophy, particularly in the hamstring or quadriceps muscles.

6. Knee arthritis can lead to a decrease in mobility, exacerbating muscle weakness and worsening symptoms.

What Is Viscosupplementation?

Viscosupplementation is a procedure that involves the injection of exogenous hyaluronic acid within freely moving joints known as diarthrodial joints, which is aimed at restoring the rheological (deformation or flow behaviors) properties of the synovial fluid. This process generates mechanical, anti-inflammatory, analgesic, and chondroprotective effects. Hyaluronic acid, a naturally occurring high-viscosity polysaccharide, is formed by the B cells of the synovial membrane. It falls under the glycosaminoglycan (GAG) group. Under normal physiological conditions, it behaves similarly to salt and is thus referred to as sodium hyaluronate or hyaluronic. Its molecular weight and spatial configuration influence the physicochemical attributes of hyaluronic acid. High molecular weight hyaluronic acid molecules braid to create a high-viscosity solution, functioning both as a lubricant and a shock absorber within the joint.

How Is Viscosupplementation Done?

Viscosupplementation involves the following procedure:

• If all the nonsurgical options for treating knee arthritis have failed, viscosupplementation can be tried.

• In this viscosupplementation procedure, a gel-like substance called hyaluronic acid is injected into the knee joint.

• Hyaluronic acid is naturally present in joint fluid and functions as a lubricant and shock absorber.

• People with osteoarthritis usually have lower levels of hyaluronic acid in their joints, leading to increased friction and pain during movement.

• By injecting hyaluronic acid into the arthritis joint, joint lubrication is enhanced, and pain is reduced.

• Depending on the product used, patients may receive one to five injections over several weeks.

• However, recent research has not shown much effectiveness of viscosupplementation in reducing pain or improving joint function.

• It has helped only a minimal number of patients by reducing pain and providing relief.

• During the procedure, if any swelling develops in the knee, excess fluids may be removed before injecting the hyaluronic acid.

• Typically, both injection and aspiration are done using a single needle inserted into the joint, although some doctors may prefer separate syringes.

• Following the injection, it is suggested to avoid strenuous activities like jogging or heavy lifting for the first 48 hours.

What Is Used in Viscosupplementation?

Sodium hyaluronate is a type of hyaluronic acid that is formed from long-chain disaccharide units of Na-glucuronate and N-acetylglucosamine. It is a natural substance found in connective tissues. When it is used as a viscosupplement to treat knee osteoarthritis, it helps lessen symptoms by acting as a lubricant and shock absorber. Additionally, it has also demonstrated benefits beyond just its direct effects, which have been associated with its anti-inflammatory properties. Following are some of the injectable solutions used:

1. 5-Injection Hyaluronic Acid Series: It is an injectable solution consisting of sodium hyaluronate, a type of hyaluronic acid. It is known to be derived from chicken comb extract and is administered through weekly injections of 25 mg for three to five weeks. Studies have demonstrated that this type has helped provide greater relief for both pain and function when compared to other non-surgical treatments.

2. One Percent Sodium Hyaluronate: It is also made of sodium hyaluronate, which is produced through bacterial fermentation. It is administered through weekly injections of 20 mg for three injections. Similar to the 5-injection series type, it does not have a cross-linking and possesses a moderate molecular weight of 24,000 to 3,600 kDa (kilodaltons). Some studies reported side effects of 1 percent sodium hyaluronate, which include back pain, joint pain, limb pain, joint swelling, and muscle pain. There is not enough research evaluating its safety in pregnant women or children under 18 years of age, but it is considered safe and FDA-approved for other adults.

3. Single Injection Hyaluronic Acid: This is a single-injection treatment made of cross-linked sodium hyaluronate that is obtained through bio-fermentation. This has been shown to remarkably improve pain, physical function, and quality of life for people with knee osteoarthritis.

4. Sodium Hyaluronate: There is a hyaluronic acid product with a high molecular weight (500,000 to 730,000 daltons) extracted from purified rooster comb extract. It is not cross-linked, so it is given in 20 mg doses over three injections. This has proven to provide long-lasting pain relief for up to six months, and it is also considered safe for repeated use for up to 30 months.

What Are the Risks Associated With Viscosupplementation Treatment?

Most people do not have any concerns regarding viscosupplementation treatment, but some people face a few problems. The most frequently occurring problem is a sudden increase in arthritis-induced pain and swelling right after the injection procedure. The less common risks associated with viscosupplementation include:

• Allergic reaction.

• Bleeding.

• Pain at the injection site.

• Infection.

• Swelling and redness.

• Reaction mimicking infections.

• Joint infections.

What Are the Contraindications for Viscosupplementation Treatment?

Conditions that make hyaluronic acid (HA) unsuitable include:

1. Allergy or hypersensitivity to hyaluronic acid.

2. Children.

3. People with bacteremia (bacteria in blood).

4. Active local injection at the target injection site.

Conclusion

Viscosupplementation treatment is used in patients who have not gained any significant improvement through other non-surgical approaches. Intraarticular injections containing sodium hyaluronate have been an effective treatment for knee osteoarthritis. However, side effects of the same injection can be avoided by obtaining a proper history and consulting a physician.