Sacrum-coccyx articulations sacro-iliaques. Technique radiologique et aspects normaux

The sacral bone and coccyx are particular entities of the spinal axis due to their lower polar location, arched morphology and unique fused vertebrae composition. These two structures look like a sunken area between both ala ossis ilii. The sacroiliac joint morphology is also complex, and therefore standard X-ray analysis of this region is often complicated, especially when it is obscured by numerous overlapping gaseous zones. Many of these problems have currently been overcome by CT scanning and MRI.