How Is Hyalgan Used to Treat Knee Osteoarthritis?

Hyalgan is a viscous solution that contains purified natural sodium hyaluronate (Hyalectin) in physiological saline. Hyalgan is one of the hyaluronates used in viscosupplementation -- a treatment that involves injecting a gel-like substance (hyaluronate) into a joint to supplement the viscous properties of synovial fluid. The injected viscosupplement helps to cushion the joint and provides lubrication to reduce friction that occurs with movement. With osteoarthritis, synovial fluid loses its lubricating properties and the goal of viscosupplementation is to restore those properties.

Hyalgan was approved by the U.S. Food and Drug Administration (FDA) on May 28, 1997, as a treatment option for knee osteoarthritis. It is considered a treatment, not a drug. The sodium hyaluronate in Hyalgan is extracted from rooster combs. Hyalgan is indicated for patients with pain related to knee osteoarthritis who have failed to achieve relief with conservative non-drug treatments and with simple analgesics, such as acetaminophen. 

Hyalgan is an intra-articular injection typically given once a week, one week apart, for a total of 5 injections. Some patients may achieve a successful outcome after 3 weekly cycles, based on study results of patients who received 3 injections and then were followed for 60 days.

There are several precautions and warnings associated with Hyalgan intra-articular injections:

• The safety and effectiveness of Hyalgan in joints other than the knee has not been studied.
• If a patient has allergies to avian proteins, feathers, or eggs, the injection should be done with caution.
• There may be pain or swelling with the injection that will subside. It is advised, as with all intra-articular injections, that patients not participate in strenuous or weight-bearing activity for 48 hours after the injection.
• The safety and effectiveness of Hyalgan injections have not been established in pregnant women, nor in lactating women. Its use has not been studied in children.

Common side effects associated with Hyalgan injections include gastrointestinal issues, injection site pain, knee swelling or effusion, local skin rash, itching, and headache. Most side effects are injection site reactions which subside after a few days, especially with rest and application of ice. Attention must be paid to symptoms which persist and may be indicative of something more severe, such as infection or systemic allergic reactions. Such severe adverse events are considered rare.

Hyalgan was the first viscosupplement approved by the FDA in May 1997. Other FDA-approved viscosupplements, along with the date they were approved, include:

• Synvisc 08/08/1997
• Supartz 01/24/2001
• Orthovisc 02/05/2004
• Euflexxa 12/03/2004