Synvisc Injections for Delaying Knee Surgery

Uses, Side Effects, and Effectiveness

Synvisc (Hylan G-F 20) is a viscous fluid derived from a substance known as hyaluronan (sodium hyaluronate). Hyaluronan is produced naturally in the body to help lubricate the joints. The form of hyaluronan found in Synvisc is made from gelatinous substances derived from chicken combs.

Synvisc is used in a form of therapy known as viscosupplementation in which the substance is injected into joint spaces to help increase lubrication.

This article discusses Synvisc knee injections, the procedure, and the side effects of Synvisc. It also discusses Synvisc injection dosage and costs.

Man wearing knee brace, cropped
PhotoAlto / Odilon Dimier / Brand X Pictures / Getty Images 

Synvisc Injection Overview

Synvisc injection procedures are approved for the treatment of osteoarthritis of the knee in people who have failed to respond to more conservative therapy, including analgesics and non-drug options.

Synvisc is delivered in a 2-milliliter injection directly into the knee joint. It has not yet been approved for any joint other than the knee. Synvisc is typically given as a series of three injections delivered weekly or every other week. To achieve the best results, synovial fluids in the cavity of the knee are typically removed before the first injection.

Another Synvisc product, known as Synvisc-One, is administered as a single, 6-milliliter shot.

Synvisc was approved for use by the U.S. Food and Drug Administration on August 8, 1997. Synvisc-One received its FDA approval on February 26, 2009.

Knee Injection Synvisc Side Effects

The most common side effects associated with Synvisc include:

  • Pain, swelling, or stiffness in the injected knee
  • Joint effusion ("water in the knee")
  • Joint nerve pain
  • Rash or hives
  • Fever
  • Nausea
  • Headache
  • Dizziness
  • Muscle cramps
  • Fatigue

Most of these symptoms are mild to moderate in severity and will resolve on their own without treatment. If any of the symptoms persist or worsen, call your healthcare provider immediately as this may be a sign of an infection or allergy.

The Effectiveness of Synvisc in Delaying Knee Surgery

Several studies have been done to assess whether hyaluronic acid injections are successful in delaying knee replacement surgery.

One study using a database of 182,022 patients who received a total knee replacement (TKR) surgery found that the injections were associated with delaying the need for the surgery.

Those who did not get the injections had the surgery within 0.7 years, those with one course of injections had the surgery in 1.4 years, while those with five courses of treatment delayed the surgery by 3.6 years. Similar results have been found in other large follow-up studies.

However, the American Academy of Orthopaedic Surgeons notes that research has not generally found that viscosupplementation effectively reduces pain or improves function. Whether you find relief or not is highly variable, although it might be enough to help you delay a total knee replacement.

Osteoarthritis of the knee is today the most common type of arthritis in the United States, affecting an estimated 13.7 million people. Based on the study findings, Synvisc is considered to be a safe and effective means of treating pain and disability in this population and, when used appropriately, may help delay surgery for three years or more.

Frequently Asked Questions

  • Is there a generic version of Synvisc?

    There is no generic version of Synvisc at this time, but there are other brands of hyaluronic injections, each with its own formulation. Alternatives to Synvisc include:

    • Euflexxa
    • Gel-One
    • Hyalgan
    • Monovisc
    • Orthovisc
    • Supartz
  • Can you exercise after Synvisc injections?

    Not at first. Avoid putting any strain on the joint for at least 48 hours after your injection. This includes high-impact activities, like jogging, or prolonged weight-bearing activities. 

  • Can you drive after getting a knee injection?

    Yes, it is safe to drive yourself home after getting a knee injection. Researchers investigated the response to breaking time before and immediately following a knee injection. The study author's found the injections did not delay response time.

  • How much do Synvisc injections cost?

    Synvisc may or may not be covered by your insurance, and may require pre-authorization or approval. The out-of-pocket cost for a 2 mL injection is around $425. Online coupons may be available.

  • Is Synvisc the same as cortisone?

    No, Synvisc is a hyaluronic acid injection whereas cortisone is a steroid. Synvisc and other hyaluronic acid injections are a type of therapy known as viscosupplementation. Cortisone injections provide steroid pain killers directly to the source of pain,

7 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.
  1. Cleveland Clinic. Viscosupplementation for Osteoarthritis of the Knee.

  2. Cleveland Clinic. Hylan G-F 20 Intra-Articular Injection.

  3. U.S. Food and Drug Administration. Summary of Safety and Effectiveness Data Synvisc-One.

  4. Altman R, Lim S, Steen RG, Dasa V. Hyaluronic acid injections are associated with delay of total knee replacement surgery in patients with knee osteoarthritis: Evidence from a large U.S. Health claims database [published correction appears in PLoS One. 2016;11(1):e0148591]. PLoS One. 2015;10(12):e0145776. doi:10.1371/journal.pone.0145776

  5. American Academy of Orthopaedic Surgeons. Viscosupplementation for Knee Arthritis.

  6. Mayo Clinic. Hyaluronic acid (injection route).

  7. Cassidy JT, McClean A, Hurley ET, Cashman JP. Is it safe for patients to drive after intra-articular knee injection? Knee. 2020;27(3):690–4. doi:10.1016/j.knee.2020.02.020

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