I'm not aware of the injections being a way to find a diagnosis, but it very well could be. As for no inflammation, you could ask your doctor about non-radiographic axial spondyloarthropathy. My son has that, and immense pain. I have ankylosing spondylitis with a lot of damage to my spine. Best to you. Warm hugs.

Get, second, third, and 4th opinions.

I get a call in 4 weeks time I guess I can ask then what he actually meant as he's aware of my lingering AS diagnosis that was taken away due to the mri not showing any inflammation yet my crp levels were raised even while taking naproxen. They interfere with crp levels he suspects the AS from symptoms but couldnt confirm so the sacroiliac joint injections he said its a step towards getting a diagnsosis i been fighting 18 years for answers x .