My recent MRI of my lumbar and sacrum showed that my sacrum has quite a curve to the posterior side and the way I understand what I have read about the sacrum is its suppose to be completely fused, well mine has joint thats not even close to being fused and two others that are only partially fused. One of my biggest pain issues is when I set, whether its at the computer or driving, I can only tolerate setting for about 15 to 20 minutes and then I am in lots of pain. The local doctors seem to think my lumbar and sacrum is normal.