Hyaluronic acid (HA) is a polysaccharide that is nearly ubiquitous in the body, and is a molecule found within the synovial fluid (SF).

It is produced by the synovial cells and chondrocytes and plays a crucial role in protecting the articular cartilage by maintaining synovial fluid viscosity. In normal joints, the viscoelastic properties of synovial fluid rely on Hyaluronic Acid. This molecule is hydrophilic and viscous in aqueous solution. It has specific rheological properties (see “Cartilage” section) due to its high molecular weight and concentration that make it the ideal lubricant and an effective shock absorber.

HA molecule
Sorbitol protecting Hyaluronic Acid schema


Sorbitol is a sugar alcohol that is found in fruit and plants.

In osteoarthritis (OA), hyaluronic acid (HA) (see “Hyaluronic Acid” section) is broken down by free radicals in a process called oxidative stress. This reduces synovial fluid (SF) viscoelasticity (see “Hyaluronic Acid” section) which is one of the factors leading to reduced mobility. 4
Sorbitol is a sugar alcohol that is found in fruit and plants. It is used in many products, such as in food, cosmetic creams, toothpaste and medications. Sorbitol acts as a free radical scavenger.

What I need to remember?

Synovial fluid is a non-newtonian fluid with unique rheological properties, acting both as a natural lubricant (viscous) and a shock absorber (elastic) at synovial joints. 1


Rheology is the study of how a substance deforms and flows following the application of a force. Synovial fluid (SF) is a non-Newtonian fluid with unique rheological properties: 1

– Viscosity: the primary function of synovial fluid is to act as a natural lubricant, reducing friction between the articular cartilage of synovial joints during movement
– Elasticity: synovial fluid also acts as a shock absorber, protecting joint tissues from damage

Synolis VA rheology schema


Osteoarthritis (OA) is a disorder that involves the whole joint.

It affects all joint tissues that communicate at the cellular level by releasing and responding to inflammatory mediators. 15 In Osteoarthritis, the joint tissue known as the synovium becomes inflamed.

Knee synovial schema
Knee osteoarthritis


​​Cartilage is made up of unique cells called chondrocytes.

Articular cartilage is a strong and flexible fibrous tissue that covers and protects the ends of long bones at the joints. Cartilage thickness varies from joint to joint. For example, cartilage may be less than 1 mm thick in the wrist. In the knee, it can be as thick as 6 mm. 17


The treatment goals of osteoarthritis (OA) are to reduce pain and improve joint function.

According to guidelines from international societies such as OARSI (Osteoarthritis Research Society International), the ideal approach to achieving these goals combines non-pharmacological and pharmacological interventions. 20,21

Knee Synolis VA hyaluronic acid injection

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What I need to remember?

If you are experiencing symptoms such as joint pain, stiffness and swelling,
talk to your doctor about whether you have osteoarthritis.

Knee radio


Your doctor will talk to you about finding a plan that suits your needs. Doctors usually treat osteoarthritis with a combination of therapies:18

  • Lifestyle modifications
  • Exercise
  • Weight Management
  • Orthotic devices
  • Medications
  • Topical (placed directly on the skin)
  • Oral (by mouth)
  • Injections (shots)
  • Dietary supplements
  • Surgery

What I need to remember?

The use of intra-articular hyaluronic acid therapy to treat osteoarthritis is growing worldwide,
due to important results obtained from several clinical trials, which reported intra-articular hyaluronic acid-related improvements in functional activity and pain management 19,20

True of false?

You can’t or shouldn’t exercise once you’ve got osteoarthritis.

Choose an answer

The Truth: You should be physically active when you have arthritis. Not only will appropriate activities decrease your osteoarthritis pain, they can improve range of motion, function, and reduce disability.

Did you know ?

What is the percentage of people affected by osteoarthritis over 65 years old?

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Did you know ?

What is the percentage of people affected by osteoarthritis over 65 years old?

Choose an answer