Supartz Injections for Knee Osteoarthritis

Supartz injection is a therapy that is used to treat symptoms of knee osteoarthritis. Its purpose is to restore the cushioning and lubricating properties of the synovial fluid (joint fluid).

Supartz is the brand name of hyaluronic acid, which is a component of connective tissue. Using a process known as viscosupplementation, the gel-like Supartz solution is injected into the knee to help relieve pain and other symptoms of osteoarthritis.

This type of treatment is only recommended if other nonsurgical options have not worked.

This article discusses what Supartz is along with the benefits, research data, and potential risks of treatment.

A patient getting a knee injection

GARO / PHANIE / Getty Images

What is Supartz?

Created from material extracted from chicken combs, Supartz is a form of sodium hyaluronate, a polysaccharide that is a type of sugar molecule. It contains glucuronic acid, which helps eliminate toxins, and N-acetylglucosamine, which has anti-inflammatory properties.

Supartz was the first injectable form of hyaluronic acid approved to treat knee osteoarthritis. This type of treatment is thought to help people with osteoarthritis who lack adequate hyaluronic acid in their knees. According to research, the solution may cushion the joint and promote lubrication. It may even help with the creation of new cartilage in the knee.

Supartz has been approved by the Food and Drug Administration for use in patients whose knee osteoarthritis hasn't improved with conservative treatments. If you have tried exercise, physical therapy, pain medications, mobility aids, and hot or cold packs and still suffer from chronic pain and reduced mobility, your doctor may recommend Supartz.

Supartz is injected into the knee once a week for a five-week cycle. Some patients may have a good response after three weeks. Its use in other joints is being investigated.

Supartz Fx

In 2015, Bioventus, the maker of Supartz, announced the launch of Supartz Fx, which contains 10 milligrams (mg) sodium hyaluronate dissolved in 1.0% physiological saline. Supartz Fx has an expanded safety label compared to the original Supartz, allowing for repeat injection cycles.

Benefits

Some research has shown Supartz to be an effective and safe way to manage osteoarthritis. It won't cure your condition, but patients have reported that it reduced pain and improved their knee function.

There is also some preliminary evidence that Supartz has the potential to impact muscle strength and activation, gait patterns, and balance, but more studies are needed in these areas.

On the other hand, some professionals have found that hyaluronic acid injections are no better than a placebo. With the absolute effectiveness still unresolved, Supartz is considered worthwhile only in cases where other non-surgical treatments aren't helping with knee pain.

Specifically, it's recommended in the following cases:

  • You cannot tolerate steroids.
  • Medications such as nonsteroid anti-inflammatory drugs (NSAIDs) or opioids are not relieving pain.
  • You've experienced significant side effects from those other medications.
  • You're unable to take NSAIDs or opioids due to contraindications.

Recommendation

The American College of Rheumatology (ACR) conditionally recommends against the use of viscosupplementation or intra-articular (into the joint) hyaluronic acid injection for the treatment of osteoarthritis of the knee in adults.

However, the ACR does state that these injections are considered better than no therapy at all in patients who have not responded to other treatment options.

Research on Efficacy

While clinical studies have upheld the safety of Supartz and the other viscosupplements, their effectiveness has been debated. The ACR's 2019 conditional recommendation against viscosupplementation was based on their conclusion that better-quality research showed little benefit. It was a reversal of their prior recommendation in favor of the injections.

Then, a randomized trial published in 2021 found that intra-articular injections of hyaluronic acid provided pain relief and improved joint function in patients with mild to medium knee osteoarthritis. However, further studies are required to substantiate these claims.

Warnings and Interactions

Your healthcare provider should use caution when considering this treatment for you. You should not receive Supartz injections in the following cases:

  • You have a hypersensitivity to sodium hyaluronate products.
  • You're allergic to avian proteins, eggs, or feathers.
  • You're pregnant or breastfeeding.

In addition, do not receive an injection in an area of skin affected by an infection or skin disease.

The safety and effectiveness of Supartz have not been studied in children.

Common Side Effects of Supartz Injections

Common side effects or adverse events associated with Supartz include:

  • Joint pain with/without inflammation
  • Back pain
  • Non-specific pain
  • Injection site pain/reaction
  • Headache

Transient swelling or pain can occur in a joint that has been injected with Supartz.

However, an analysis of five well-designed clinical trials revealed no significant difference between Supartz and control groups regarding adverse events.

Patients are advised to avoid strenuous or weight-bearing activities in the 48 hours following injection.

Outlook

Supartz injections do not work for everyone. In cases where they have been successful, it takes several weeks and multiple shots to feel any relief.The benefits then usually last several months. They may even last a year.

However, the treatment is a temporary fix. Often Supartz is used as a final non-surgical approach to pain relief. Eventually, a knee replacement may be needed to relieve pain and regain mobility.

Summary

Hyaluronic acid injections like Supartz are not proven to help with osteoarthritis of the knee, but when there are no other options other than surgery, your healthcare provider may recommend giving the treatment a try. Some people do report pain relief along with improved movement and strength after a series of shots over several weeks.

If you do have success with the shots, though, it will not last more than a few months or a year. Supartz does not reverse or cure osteoarthritis. Knee replacement surgery may be the only option for long-term benefits.

A Word From Verywell

Spartz is approved by the FDA but comes with warnings that it may not help at all. The injections themselves should not be too painful or inconvenient, so as long as you don't have allergies or contraindications, you may have nothing to lose.

When weighing your options, it's important to consider what the risks are for a treatment that has few proven benefits. Discuss the procedure with your healthcare provider, and think about whether it is time to look at a more invasive but long-term surgical solution to chronic knee problems.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. American Academy of Orthopaedic Surgeons. Viscosupplementation Treatment for Knee Arthritis.

  3. Creaky Joints. Intra-Articular Hyaluronate (Hyaluronic Acid Injections).

  4. Bioventus. Supartz Fx prescribing information.

  5. Bannuru RR, Brodie CR, Sullivan MC, McAlindon TE. Safety of repeated injections of sodium hyaluronate (SUPARTZ) for knee osteoarthritis: A systematic review and meta-analysis. Cartilage. 2016;7(4):322-332. doi:10.1177/1947603516642271

  6. Kolasinski SL, Neogi T, Hochberg MC, et al. 2019 American College of Rheumatology/Arthritis Foundation guideline for the management of osteoarthritis of the hand, hip, and knee. Arthritis Rheumatol. 2020;72(2):220-233. doi:10.1002/art.41142

  7. Xiao J, Hu Y, Huang L, et al. Injection route affects intra-articular hyaluronic acid distribution and clinical outcome in viscosupplementation treatment for knee osteoarthritis: A combined cadaver study and randomized clinical trial. Drug Deliv Transl Res. 2021;11(1):279-291. doi:10.1007/s13346-020-00793-6

  8. Drugs.com. Supartz (injection).

By Carol Eustice
Carol Eustice is a writer covering arthritis and chronic illness, who herself has been diagnosed with both rheumatoid arthritis and osteoarthritis.