@healthinsurancesucks - I am sorry! I know your pains well! I will skip all my stories but ask if you have tried shoe implants (those little leather pieces you put in your insoles) You can get fitted at the Comfort Foot Store. IF they relieve your sacral joint pain you might be surprised that your hip was tweaked during your injury. My "gait" was tweaked during childbirth. Also, it may be possible you have a piriformis disorder. That is where the glute muscles press on the nerves exiting the spine and cause problems with pain. Mine was kinda fixed after my hips and my lumbar was replaced and fused.
Also - RFA/RFI the "pulse method" did zero the "heat method" definitely worked! Sometimes you have to go back for the same area twice.
Also - find a really good MFR therapist. Worth their weight in gold!!! They will adjust you and if they are good (not the 10 minutes which insurance covers in P.T.) but a good one who will work on your for an hour or so - they will not only relieve your pain but be able to help with what it is and what it is not. They really know by seeing what responds. You might need to go a few times. But you will feel better and feel like you are making progress!
Finally: BOTOX! I did botox for my lumbar pain because the muscles were in spasm and as they press on the nerves and pull at the connective tissue you have constant pain. Getting them to relax through the paralysis will not only relieve your pain but help you with more diagnosis.
Fight to get this all covered. I did.
You did an EXCELLENT job of explaining everything! Most people don't so it is really hard to point people in clear directions.
I will take an intuitive guess: Your accident tweaked your hip out of alignment, and you have some arthritis which, when inflammatory by nature, causes pain. (Make sure you are on an anti-inflammatory diet. I have to be. Good luck. My journey has been lifelong - I am 69. My auto accidents and congenital issues influenced/exacerbated my lifelong issues. Builds character I say!