I have psoriatic arthritis and suffer the same symptoms you described. My rheumatologist says that spinal involvement is common. I have been through many, many medications. The one I find the most helpful is enbrel. It is an immunosuppressive medication the helps to decrease inflammation. I also take clinoril and plaquenil. Right now I'm having trouble with an arthritic rib, and the doc suspects maybe more of the rib joints may be inflammed. I think many types of arthritis will cause the symptoms you're having. I hope you have good luck with your rheumatologist. One thing I can say is that it took me many years to get to see a rheumatologist, and once I did it made a huge difference. I have much less pain and stiffness, and fewer flareups. Good luck!