I had this problem too, physio made it much worse, I was on morphine which did nowt but make me feel drunk and sick and couldnt walk sit or stand , saw a specialist at local Nhs who at the time was pioneering knee surgery, he advised, and did, instead of fusion, just chipping away the parts of the discs that were bulging onto the nerves, 5 days in hospital and 3 months of physio later I was nearly as good as new That was in 1992, he told me it should be ok for 10 years at least, now I still have sciatica and back pain but nothing like as excutiating and now know when to take things easy