Only way to tell really is through X-ray. If the X-rays say you have no arthritis then it can’t be that.
I have bone pain, muscle pain and nerve pain. Because I have them all, I can tell the difference. I told them for years that I felt as though I had broken bones in my back. Lots of x-rays, and lots of different types of x-rays and many, many years later, it takes my Rheumatologist to TELL them to report on my SI joint, before anyone SEES it. And none of the Doctors that read X-rays noticed the stenosis, but the Chiropractor caught it looking at the films, and my GP confirmed.
Chances are if the x-ray orders were to look at the SI joint, it was targeted, so I would say you are clear, could be other connective tissue,
I think this part belongs to rebecca about lyrica helping pain at SI joint area
could even be swelling that is compressing nerves, especially if Lyrica is helping, but I may be getting you mixed up with Rebecca with that.
BUT I am not a Doctor, and I cannot feel your pain, if these Doctors are not seeing what you are feeling, then time to move on to a new doctor. I will tell you that the Chiropractor has told me that if muscles, tendons, ligaments are damaged or shrink away from the bone, it can feel like bone pain. Again, I don't feel YOUR pain, and have not gone to med school.