This is a strange one, I was watching a documentary on tv here in England recently and although the old weed of wisdom has a lot of pain relievers, it is actually a depressant and people who have had long term exposure to smoking the old bob hope have actually been found to have a lot of problems, for instance the high rate of 'schizophrenia' and depression that has been documentated and the NHS is now screaming out. There is however, a form of cannabis/hemp which has had the 'tripping' feeling removed and it is used for people who need pain relief. I would rather take that form of 'joint' than have the side effects of smoking the stuff you would buy on a street corner from your local merchant! Good luck and here's hoping you manage to find the pain relief you need.
Tracy