Occasionally a cortizsone shot's necessary to get rid of joint stress. Incredibly effective, but not a long-term solution in that the symptoms will recur if the causes aren't removed.
I actually agree with pumpster on this one.
Also, animal studies have shown effects of weakening of tendons and softening of cartilage with cortisone injections. Repeated cortisone injections multiply these effects and increase the risk of potential problems. This is the reason many physicians limit the number of injections they offer to a patient.
SG