Viscosupplementation (Supartz): What You Need to Know

What is viscosupplementation?

Viscosupplementation is an injection treatment for osteoarthritis (OA) — most commonly of the knee. It involves injecting a gel-like substance called hyaluronic acid (HA) directly into the joint to supplement the natural fluid your body produces.

Healthy joints contain synovial fluid that’s rich in hyaluronic acid — it acts as a lubricant and shock absorber. In osteoarthritis, the quantity and quality of this fluid breaks down. The cartilage cushion thins, bones begin to contact each other, and the joint becomes stiff and painful. Viscosupplementation restores some of that lost cushion by adding hyaluronic acid back into the joint space.

Think of it like restoring oil to a dry engine. It doesn’t rebuild the parts that have worn down, but it can meaningfully reduce friction and pain.

Why we use Supartz

Several viscosupplement products are available. At Synergy Rheumatology, we use Supartz FX (sodium hyaluronate). Supartz is a low-molecular-weight hyaluronic acid derived from rooster comb. Compared to single high-dose injection products, Supartz uses a series of smaller injections that allows the joint to adapt gradually and tends to be well tolerated with minimal post-injection swelling.

Supartz has a long track record — it has been used in millions of injections worldwide and is FDA-approved for knee osteoarthritis.

Who is this for?

Viscosupplementation is appropriate for patients with knee osteoarthritis who:

• Have mild to moderate OA — the joint still has some cartilage remaining (it won’t help a bone-on-bone knee that needs a replacement)
• Have tried conservative measures like physical therapy, anti-inflammatory medications, or activity modification without adequate relief
• Want to delay or avoid knee replacement surgery
• Cannot take or tolerate anti-inflammatory medications (NSAIDs)
• Are looking for a non-systemic option — the medication stays in the joint, with no whole-body side effects

Important: Viscosupplementation is not a cure for osteoarthritis. It does not regrow cartilage or reverse joint damage. The goal is to reduce pain and improve function, which in many patients it does effectively.

What about other joints?

Supartz is FDA-approved for the knee only. However, viscosupplementation can be performed off-label in other joints — shoulder, hip, ankle, or base of thumb — when the clinical situation warrants it. Insurance typically does not cover off-label joint injections, so these would be an out-of-pocket expense. If you’re interested, we can discuss whether it’s a reasonable option for your situation.

The procedure

We perform all viscosupplement injections under ultrasound guidance. Dr. Fellows is RhMSUS certified (Registered in Musculoskeletal Ultrasound) and uses our in-office Mindray MX7 ultrasound to guide every injection. Here’s why this matters:

• Accuracy — ultrasound confirms the needle is inside the joint space before injecting, which means the medication goes exactly where it needs to go
• Fluid drainage — if your knee has excess fluid (an effusion), we can drain it through the same needle before injecting, which improves both comfort and effectiveness
• Safety — real-time visualization avoids surrounding structures like tendons and blood vessels

Here’s what to expect:

• The skin is cleaned with antiseptic
• The ultrasound probe is positioned to visualize the joint
• The needle is guided into the joint under direct visualization — you’ll feel pressure and a brief sting
• If fluid is present, it’s drained first
• The Supartz is injected — this takes just a few seconds
• A small bandage is applied, and you’re done

Each session takes about 10 minutes from prep to bandage.

The treatment schedule

We use a series of 3 weekly injections — one injection per week for three consecutive weeks. This provides cumulative benefit with each session building on the last.

• Week 1 — first injection
• Week 2 — second injection
• Week 3 — third injection

Most patients begin to notice improvement during or shortly after the series. Maximum benefit is usually felt 4–6 weeks after the final injection.

The effects typically last 4 to 6 months, and in some patients longer. The series can be repeated when the benefit wears off — many patients do this once or twice a year as part of their OA management.

What to expect afterward

• Immediately after: The knee may feel slightly full or stiff from the injected volume — this is normal and resolves within hours
• First 24–48 hours: Mild soreness or swelling at the injection site is common. Ice and rest help.
• Over the following weeks: Pain and stiffness gradually improve as the hyaluronic acid integrates into the joint fluid

Aftercare instructions:

• Rest the knee for 24–48 hours — avoid prolonged standing, running, heavy lifting, or high-impact activity
• Ice the knee for 15–20 minutes at a time if it feels sore or swollen
• Light activity is fine — walking, gentle movement, and daily tasks
• Avoid soaking the injection site (no baths, pools, hot tubs) for 24 hours; showering is fine
• Acetaminophen (Tylenol) can be taken for mild discomfort if needed

Side effects

Viscosupplementation is very well tolerated. Serious side effects are rare.

Common:

• Mild pain or swelling at the injection site for 1–2 days
• Warmth or stiffness in the knee after the injection

Uncommon — contact us if you experience:

• Significant swelling, redness, or warmth that worsens after the first 48 hours
• Fever after the injection
• Severe or increasing pain that doesn’t improve with ice and rest

Allergy note: Supartz is derived from rooster comb (avian source). If you have a known allergy to poultry, eggs, or feathers, let us know before treatment so we can assess whether this product is appropriate for you.

Frequently asked questions

How is this different from a cortisone shot? A cortisone (corticosteroid) injection reduces inflammation directly and provides fast relief — often within days — but the effect is temporary and repeated steroid injections can weaken cartilage over time. Viscosupplementation works differently: it restores joint lubrication rather than suppressing inflammation. The relief takes longer to develop but tends to last longer, and there’s no cartilage-weakening effect. Some patients benefit from both — a steroid shot for acute flares and viscosupplementation for ongoing OA management.

Does insurance cover it? Most insurance plans cover viscosupplementation for knee osteoarthritis when conservative treatments have been tried first. Prior authorization is sometimes required, and our office handles that process. Off-label use in other joints is generally not covered by insurance.

How do I know if I’ve had enough benefit to repeat the series? If you had meaningful improvement in pain and function that lasted several months before gradually returning, that’s a good candidate for repeat treatment. If you noticed little or no benefit after the full series, repeating it is unlikely to help and we should discuss other options.

Is there any downtime? No real downtime — most patients drive themselves to and from the appointment and return to desk work or light activity the same day. Just avoid high-impact activity for 48 hours after each injection.

This handout is provided for educational purposes and does not replace individualized medical advice. Always follow the specific instructions given by your rheumatologist.