Don't know that it's the "hurtiest", but it is the most recent. I had an injection of steroids in my finger (well, base of my finger I suppose) to try and free up by "trigger finger" last week. That was very unpleasant.
Doing better now. Pain was gone by the next morning. Doc said a week to two weeks to really know if it worked, but it's about 90% better. Still locks up a little bit, but not nearly as badly.
Cleveland Clinic, University Hospital? I gotta medical student at Case Western that knows some people. Currently doing research project on radiation medicine for cancer cure. Fascinating subject.