Orthovisc Treatment for Knee Joints

Orthovisc is a thick or viscous solution of high molecular weight, highly purified sodium hyaluronate in physiological saline. Hyaluronan, which is found in the human body, lubricates the joints and acts as a shock absorber. With osteoarthritis, natural hyaluronan is compromised.

Orthovisc is one of the hyaluronates used in a procedure known as viscosupplementation. Orthovisc is a non-animal sourced viscosupplement that is injected directly into the knee joint to restore the cushioning and lubricating properties of the normal joint fluid (i.e., synovial fluid).

Orthovisc was approved by the U.S. Food and Drug Administration (FDA) on February 4, 2004, for the treatment of pain associated with knee osteoarthritis in patients who failed to achieve adequate relief with more conservative treatment (e.g., exercise, physical therapy) and the use of simple analgesics, such as acetaminophen.

Orthovisc is considered a treatment, not a drug, as is the case with other hyaluronates used in viscosupplementation. Orthovisc is administered as a series of 3 to 4 weekly intra-articular injections (given once a week). According to the manufacturer of Orthovisc, it can produce beneficial effects that last up to 26 weeks.

People with a known hypersensitivity to hyaluronan products should not be treated with Orthovisc or any of the viscosupplements. Also, people with a known allergy to birds or bird products should not use Orthovisc. (Note: This warning is applied to all hyaluronan products.) People with an infection in the knee joint, other infection, or skin disease in the area where the injection would be given should not be treated with Orthovisc.

The most common adverse events associated with Orthovisc treatment during clinical studies included arthralgia, back pain, and headache. Other adverse events were local injection site reactions.

As with any intra-articular injection, it is recommended that the patient avoid strenuous activities or prolonged weight-bearing activities for 48 hours. Also, it should be noted that pain or swelling may occur after the injection, but normally it will diminish after a short time period. Also noteworthy, the safety and effectiveness of Orthovisc have not been established in pregnant women, lactating women, or children.

Other FDA-approved viscosupplements, along with the date they were approved, include:

• Hyalgan 05/28/1997
• Synvisc 08/08/1997
• Supartz 01/24/2001
• Euflexxa 12/03/2004

The American Association of Orthopaedic Surgeons (AAOS) has stated that while some patients report relief of arthritis symptoms with viscosupplementation, the procedure has never been shown to reverse the arthritic process or re-grow cartilage. The effectiveness of viscosupplementation in treating arthritis is not clear. It has been suggested that viscosupplementation has the best chance of being effective when arthritis is in its early stages (i.e., mild to moderate knee osteoarthritis).