Name of medication injected in knee with arthritis and you must walk slow and stay off knee for 3-4 days

There are several, maybe you can find the answer here.

http://www.bigkneepain.com/knee_pain_meds.html

Cortisone is the most common and most effective, however, it also can be a carcinogenic when taken over long periods of time.

For the most part, you are either looking at cortisone, a steroid, or a substance known as Synvisc (there are other brand names for these drugs).  Synvisc is used to relubricate the knee when the cartilage has been worn away.  Synvisc is usally administered in a series of 3 to 5 injections, usually a week apart.  Cortisone is used to reduce inflamation in the tendons and connective tissue of the knee.  They try to avoid retreating the same area for up to three months or more as cortisone can turn your tendons into mush.