Osteoarthritis is a degenerative disease that mainly affects the cartilage of the joints and is one of the leading causes of disability in the United States. Cartilage works like a "shock absorber" on the joints and allows bones to glide over one another. Joints also have a small amount of a thick, gel-like substance called synovial fluid that cushions the joint and provides the lubrication needed to reduce friction. As we age, the surface layer of cartilage breaks down and wears away slowly. At the same time, the synovial fluid starts losing its ability to lubricate the joint. This combination of issues causes pain and stiffness, limitation of joint motion, and some inflammation that can worsen over time. In its early stages, osteoarthritis is treated with activity modification, weight loss, anti-inflammatory medications, physical therapy, and corticosteroid injections, or a combination of these before considering surgery. If the pain continues to limit your activities after trying all the above treatment methods, viscosupplementation may be an option.
Viscosupplementation is a procedure done in the office where a thick fluid called hyaluronate is injected into the joint space, usually the knee. This product comes from avian sources like rooster combs or bacterial fermentation. For that reason, if you have an avian allergy (ex. eggs), you should avoid this product.
It is thought that injecting hyaluronate will improve the lubricating properties of the synovial fluid, restoring some of the mentioned cushion capacity. However, it is important to note that there is no cure other than surgical joint replacement. This injection will not reverse the arthritic process or re-grow cartilage. The improvement provided by the injection will reduce the pain from osteoarthritis, improve mobility, and provide a higher and more comfortable activity level.
Depending on the product used, you might receive one to five shots over several weeks. You should avoid strenuous activity, such as jogging or heavy lifting, for the first 48 hours after the procedure. The most common reported side effects are:
- Temporary injection-site pain.
- Swelling or redness.
- Rash and itching.
- Bruising around the joint.
- Fluid accumulation in the injected joint.
These reactions are mostly mild and don't last long. As with steroid injections, infection and bleeding are also rare complications. You can apply an ice pack to help reduce these symptoms.
Not all patients feel relief with the injections. Most patients report the most significant pain relief 8 to 12 weeks after treatment. How long the pain relief lasts varies. Some patients have reported relief for more than six months after the injections. If the injections successfully provide that pain relief, they may be repeated after some time, usually after six months.
It is not very clear how effective viscosupplementation can be in treating arthritis. It has been suggested that viscosupplementation is most effective if the arthritis is in its early stages. However, more research needs to be done on this topic to understand better how effective these injections can be.