The natural fluid in the knee joint is composed of hyaluronic acid.  When people get arthritis, the normal characteristics of this fluid becomes altered and less functional.  It was originally found in the comb of a rooster and is commonly known as "the chicken jelly" or "rooster comb fluid." These injections act as a lubricant in the joint and are intended to make your knee fluid healthier over time. There are different brands such as Synvisc, SynviscOne, Supartz, Euflexxa, Orthovisc and Hyalgan.  It is a series of injections once a week for either 3 or 5 weeks depending on the brand used.  It is a fairly painless and quick procedure performed here in our office.