Fluid pockets in lower back
I'm in the midst of sacroilliac problems, but no one has mentioned "fluid pocket." I do have range of motion issues, but have seen that attributed to normal degnerative changes with aging. But I will pay attention to your posts as I don't have much confidence in my local doctors.
I too had lower back and groin pain, when I had an MRI it showed fluid in the sacroilliac area. I have now been diagnosed with Ankolising Spondilitis, this in addition to two other autoimmune diseases, Microscopic Polyangitiis and APS. I now have to inject weekly with a click pen and am trying to reduce prednisilone which I think will be a longer job as each 5mg drop brings on the pain again, am at 10mg at present. Hope you don't have this but may be worth investigation
I hope you get some help with this soon, it sounds very uncomfortable, I hope your rheumatologist/GP can look into this pronto! M x