I have treated about 3000 patient with depot corticosteroid injections - I have not seen a single case of avascular necrosis.
When injected in the lig the cortisone can not easily escape from there, thus systemic side effects are very rare.
And - I will certainly be cautious. And report herein.
My cautions and ‘worst case scenario’ side effects are more to help others realise that this is not a good idea for a layman to try. I know you understand the dangers and have the experience to do this, but I wouldn’t be doing my ‘mod job’ if I didn’t point out potential pitfalls. I know you understand that I have to do that. :)