Thanks to everyone for their nice comments, texts and emails. It looks like the op was a success: surgeon says it was a “textbook” job and he managed to get a big chunk of disc out without too much hassle. So I can walk, the sciatica’s gone completely (although I’ve been warned that it may come back as an echo over the next wee while) and the scar won’t be too bad.
All I need to do now is spend a few weeks munching painkillers (I feel as if I’ve been smacked in the small of the back by a car) and getting my strength back. I shouldn’t be sitting at the laptop at all, so I’ll disconnect with a guilty expression on my face :-)