The range of movement that humans can make depends on the flexibility of their joints. Fluid inside the joints allows bones and ligaments to move relative to one another without damage from friction. Sometimes this fluid in the joints becomes more watery and is less protective, causing the pain and inflammation of osteoarthritis. Hylan G-F 20 is a commercial preparation of substances that replace the inefficient fluid to improve the symptoms of the disease.
In animals, joints are covered by a capsule of tough material, with fluid, called synovial fluid, inside the capsule. This acts like lubricating oil, and is usually efficient enough to allow people have a normal range of movement. When a person suffers from osteoarthritis, however, the lubricating effect of the synovial fluid is reduced. This weakening of the joint can also result in further damage to the area, such as the surrounding cartilage.
One major component of synovial fluid is called hyaluronan, which is a molecule that gives the fluid its flexibility and its thickness or viscosity. A certain level of vicosity is necessary for a healthy joint, and osteoarthritis lowers the viscosity of the fluid. Hylan G-F 20 is a fluid that is very viscous. When it is injected, the extra viscosity improves the condition of the joint.
Hylan G-F 20 is a natural product, as the manufacturers make it from the combs from the heads of chickens. The two major ingredients in the product are two different forms of hylan molecules, which are related to the natural hyaluron. These molecules interact with each other and link to each other, which helps the molecules to survive in the joint and to confer viscosity to the fluid. Another main component of Hylan G-F 20 is sterile sodium chloride in water, which helps keep the hylan substances in a fluid form.
This product is available as an injection, and is typically suitable for people whose arthritic pain in the knee does not benefit from over the counter painkillers and anti-inflammatories. Different Hylan G-F 20 products are offered, with varying treatment protocols. A patient may receive just one injection, which then has beneficial effects for about six months.
Another treatment option is to receive three injections, each a week apart, which also can have benefits for several weeks afterward. The area where the medication is injected can develop swelling and pain, and the skin can become irritated. Headaches, tiredness and fever are some of the other possible side effects.