I had one five years ago. I have moderate sentosis in my lower back. (Sciatic Nerve being pinched by shrinking disks and swelling) It helped a great deal by reducing the swelling until last week. Spent Tues morning in emerg begging for another one but they decided to give me different injections of an anti-spazzing meds and heavy duty pain killers, plus a script for T3's. It is way better now but feels like another week of ginger walking. If this doesn't do it they will give me another spinal tap and when that wone wears off the only other option is surgery.
Go for the injection for sure!!