I hope you get a good second opinion. I underwent a bunch of the same stuff: rheumatology workup, tests for infection, etc. Mine ultimately was ruled "nonspecific synovitis."
I take it that you were tested for things like Lyme disease? Lyme is becoming epidemic here. My husband and several friends have been diagnosed.
I know that there is debate about the existence of low grade infections, which can be hard to diagnose.
I hope you get some answers soon. The waiting is hard . . . But at least you're scheduled to see a recommended surgeon.
Here in the US, the only tests that get repeated are, for instance, xrays. Each surgeon seems to want to do their own xrays, and I've heard of specialists repeating MRIs done elsewhere because apparently they differ in quality as well.