Hi Elphers: Sorry that you don't have an answer to your back pain. It's true that some compression fractures don't show up on an x-ray and some people have to go through a mri to find it. That's not to say that your problem isn't something else either.
If you could go to a spine specialist or ortho they would probably run a whole battery of tests including an mri, ct scan and possibly a emg. Have you injured your back lately?
I've had many back surgeries so I'm familiar with many different types of problems, but the first thing you have to do is get a diagnosis. I was also thinking about something else and wondered; did the gyno look at the actual films from the x-rays, or did they read the radiologists report? If you go to a surgeon, (ortho, neuro) they won't read a radilogists report because they aren't that accurate on fx's etc. A surgeon will only look at the actual film to determine if there is a problem. If you can get to a different dr (surgeon) you'd be much better off on a dx. If you haven't injured your back recently you still need to find the cause of the pain.
Good luck with this, if you have any specific questions fire away.