Total knee replacement surgery is one of the most common procedures to treat osteoarthritis of the knee. Over 600,000 knee replacements are performed each year in the United States. It is a great procedure for those people whose knee has worn out and they are unable to walk or perform activities of daily living.
Several causes are responsible for arthritis, but the bottom line is that the joint surfaces have worn down, the meniscus between the femur and the tibia are usually torn, shredded or completely gone. The lack of adequate cartilage between the bones causes pain due to the absence of cushioning at the joint.
Arthritis is a progressive disease. It doesn't get better. Sure you can do exercises to strengthen your knee and increase your range of motion. However, arthritis is dynamic and not static. The options for treatment are: 1. Non-steroidal anti-inflammatory medication, 2. Physical Therapy, 3. Steroid Injections, 4. Partial Knee replacement if you fit certain criteria, 5. Total knee replacement and 6. Viscosupplementation.
If you are 40 years old and have been diagnosed with osteoarthritis, viscosupplementation is a viable option. Anyone who reads the sports section in the local newspapers sees these full page ads touting a "new" solution for painful knees. In reality viscosupplementation has been around for quite some time. It was approved by the FDA for use in 1997. The other name for viscosupplementation is hyaluronic acid.
There are a number of pharmaceutical companies producing hyaluronic acid injections. Synvisc and Hyalgan were two of the early products. They use an animal base harvested from rooster combs. Recently Orthovisc and Supartz have come to the market and they are bioengineered and have no animal products. The material is a gel which is directly injected into the knee joint. It is an office procedure and orthopedic surgeons can easily inject the material into the knee joint without the use of fluoroscopy.
Depending on the manufacturer will determine how many injections are required. Most patients undergo a series of 3 injections at one week intervals. The gel works by increasing the viscosity of the fluid inside the knee joint. I often tell my patients to think of it like adding STP oil additive to your engine oil. Over time and with arthritis the synovial fluid becomes thin. This will lessen the cushioning effect in the knee joint.
Some patients get a little relief after the first injection, but most will tell me that it takes the second and third injection to notice substantial benefit. Side effects are rare with viscosupplementation and are usually limited to swelling. However, in my experience this is quite unusual.
Most patients will get six months relief with a series of injections. During that time their knee will usually feel much better and it may allow them to exercise and if needed, lose weight. If symptoms reoccur then the injections can be repeated.
Viscosupplementation is an alternative procedure for those younger patients with degenerative changes in their knees or those patients who are just not ready to proceed with a knee replacement.