Haha well lets hope we don't have to be getting MRI's any time soon, I watch the show House also, its at the top of my list right next to Dexter which is another very well done show, although slighlty different in premise(Dexter being about a crime fighting serial killer.. it could happen).
Back on topic, if you would like to know my thoughts on our mutual problem, and although doctors will all tell you something different, here is my theory.
I think a big reason all of our joints seem to be under pressure and in the need of some good cracking and repositioning at times, is due to stress, and I don't mean that psycho babble mental stress needing a vacation and what not.. I'm referring to more physical stress, where we may, albeit not knowingly, tense all of our muscles and joints during the day, just from being stressed out or overworked or whatever the cause may be, even bad posture and the way we sleep may contribute to it. So when the doctor told you to take a hot bath, the reason this works is because it relaxes all of your muscles, which are otherwise under alot of strain. So although I'm sure a vast majority of the population are stressed from their jobs and or family/ housework etc, the people that don't have our problems are the people who most likely are able to relax and get good a nights sleep, which may just be what our joints need. Although this wouldn't take effect right away, having 1 or 2 or even a week of good sleep would not take our problem away, I think if we can find a way to relax everynight sleep well and not tense up so much during the day, gradually we may notice our joint problems less and less and with time not at all.
Now I'm sure while we work on all of this there are things to do that will assist us, such as the hot baths, and there are probably types of drugs out there that will help you relax your muscles, but for me I think I will stay away from any pharmaceuticals, and just try to develop better sleeping habits and try to remeber to relax more often, and just not think about the problem as much, because the more you think about it the more it bothers you, believe me I know that as well as anyone.
So I hope this applies to you, and I hope that it helps, because I honestly don't think it could be anything else other than the body not being fully grown, which obviously in most cases for people over 20 is most likely not the case.