Tom,

Hypnosis can be used for some types of pain control/management. I do not know if it can be used for chronic joint pain.

If you ever want to see something mind-boggling, watch the video at this link: http://www.abc.net.au/catalyst/stories/s1440855.htm (click on the video camera icon to play). There is a weekly TV magazine show called Catalyst on the Australian Broadcasting Company network. The link is to a story they did a number of years ago on hypnosis. Just ignore the first two minutes where they show a hypnosis stage show--these are what tend to give hypnosis a bad name. The rest of the story is well done and informative. One of the people they cover in this story is a woman named Beverly who is allergic to conventional anaesthetics. She needed to have surgery, and the video follows her as she undergoes training to use hypnosis for anaesthesia. During the last two minutes of the story (at about minute 25), you actually get to see her undergo surgery with hypnosis as the only form of anaesthesia. They film the surgeon making the incision in her abdomen while the patient is chatting away with the hypnotist who is seated beside the operating table.