I'm 49 and have severe arthritis in my left knee only. I've taken cortisone injections for several years but they finally got to where they only last about 6 weeks. Started the 3 injections of Syntex two weeks ago. Got my last of 3 injects two days ago. I was feeling better and walking better before I had this last injection. Now I feel like I've had a relapse. It hurts so much and I've got black & blue mark about the size of a quarter where they gave me the shot. I'm just hoping this is temporary stiffness. My knee did feel better after 2 injections.