@ellerbracke If the cortisone did not help it may not have gotten to the actual site. I had a number of cortisone injections for hip bursitis that did not help beyond initially. I did some research and discovered that there is such a thing, "guided" injections, where they inject using an x-ray to pinpoint where.
I went to a doctor in Boston, I don't really recall what made me choose him, and he said he did not need to do it that way. I was overweight and he asked me if any of the doctors had used a long needle. I did not believe any had, so that was how he proceeded. His explanation was very gentle, he said that patients with a little extra padding needed a longer needle to get to the site better. Sure enough, he was right. I went to him three times for cortisone injections and he hit the spot every time. I have lost the extra padding so I now use a doctor closer to home.
If you do not have any "extra padding" it could still just be that the doctor did not hit the spot well enough. Good luck with this.
JK