Viscosupplementation Injections

These injections have been used for over 10 years and provide a longer lasting effect than corticosteroid injections without the concerns of causing cartilage harm.

Viscosupplementation injections basically acts by introducing exogenous (produced outside the body) hyaluronic acid into the knee joint. In our knees, we have a liquid known as the synovial fluid which acts as a natural lubricant and shock absorber.

The fluid properties change as it is subjected to different mechanical forces. When a sudden force is applied to the fluid, it tends to act in an elastic manner (like a tennis ball) and resist the force applied.

viscosupplementation injections

In our knees, we have a liquid known as synovial fluid which acts as a natural lubricant and shock absorber, to help dissipate the forces that the joint undergoes during impact activities (eg. Running or jumping)

This property is very useful as a shock absorber to help dissipate the forces during impact activities (eg. Running or jumping). When it’s subjected to a slow steady force, the fluid behaves like a viscous (thick) liquid that lubricates the moving surfaces.

Which allows it to decrease the friction between the 2 cartilage surfaces in the joint. The principal component that is responsible for this property in synovial fluid is a large molecule known as hyaluronic acid.

This molecule is produced within the knee joint. However, when the knee joint undergoes degeneration, the amount of hyaluronic acid in the synovial fluid also decreases.

Hyaluronic Acid - viscosupplementation injections

How can it help you?

Injection of exogenous hyaluronic acid into the knee joint aims to improve the quality of the synovial fluid and help in the shock absorption and lubrication of the joint. The presence of the injected hyaluronic acid may also stimulate the joint to produce more of its own endogenous (produced by the body) hyaluronic acid.

This could be the reason why the effects of a hyaluronic acid injection have been observed to last for a much longer period than corticosteroid injection. The onset of effect for this injection has also been shown to be slower than a corticosteroid injection.

“…the effects of a hyaluronic acid injection have been observed to last for a much longer period than corticosteroid injection”

It typically takes 6 weeks or more before the maximal effects are noticed. However, there is also some controversy surrounding the use of such injections. Despite some studies showing good results from its use, other studies have also refuted these findings and noted that there may only be a marginal group of people that derive clinically important benefits from the injection. As such, there may be opposing recommendations from different groups of specialists.

For example, the American Academy of Orthopaedic Surgeons (AAOS) does not recommend the use of hyaluronic acid injections for the treatment of osteoarthritis as articulated in recommendation number 9 of their 2013 clinical practice guidelines in the treatment of osteoarthritis, while the American College of Rheumatology (ACR) still recommends physicians to consider its use.

Despite the controversy, viscosupplementation injections still remain a readily available form of treatment for patients with painful knee conditions resulting from osteoarthritis. There have also been patients who have reported improvements in their condition after injection even though studies may show differing conclusions.

In Part 3 of this series, we talk about Plasma Rich Plasma (PRP) injections and discuss the benefits and use of this treatment. Click on the link to view the next article. 

 

Dr. Sean Leo

 

About the Author
Dr Sean Leo is a former SAF Medical Scholarship recipient and served as CO of the Medical Classification Centre at CMPB. After retiring from active military service in 2012, Dr Leo joined Changi General Hospital where he was the Director of Hip and Knee Service.  He subsequently went into private practice at Mt Elizabeth Novena Hospital. As an orthopaedic surgeon, Dr Leo is specialized in knee and lower limb surgery with a focus on sport injuries, rehabilitation and performance. 

For an appointment, email appointment@orthokinetics.sg.

 

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