Yes, I agree. I didn't make it clear in my OP but I'd bite your hand off right now for that injection. I've been referred and will sign the million page exempt-from-liability form quite happily as it's been the worst it's ever been recently. It's off-label though (corticosteroid epidural).
I will get around to replying to all the other very kind and generous suggestions by everyone and I'm pretty much pursuing all avenues as the totally conventional route isn't working for me and there are other risks too. I'm really looking for greater quality-of-life, as much for my long-suffering wife as for me. I've had some great options today and that helps enormously.