The sacrum refers to all parts. Its parts are called sacred vortexes when mentioned individually. The rotation of the sacrum is higher and forward, while the coccyx moves behind the ilium, sometimes as « nutation » (from the Latin term nutatio, meaning « nodding ») and the reverse movement, postero-down of the sacrum relative to the ilium, while the coccyx moves backwards, « Counter-nutation ».  For straight vertebrates, the sacrum is able to move easily independently along the sagittal plane. Turning backwards, the top (base) of the sacrum moves relatively towards the ilium; Turning forward, the top moves backwards.  To our knowledge, this study is the first to describe the reliability of the AOSpine sacral classification system among a global group of experienced spinal and traumatic surgeons, with significant intra-preferential reproducibility to excellent and moderate to significant interdisciplinary matching for most types of fractures. These results indicate that this classification system can be reliably applied to sacred injuries, which is an important step in standardizing treatment. In some cases, the sacrum consists of six pieces or is reduced to four in number.  The bodies of the first and second vortex cannot unite. In short, the sacred classification consists of a hierarchical system, divided into three main types based on morphological criteria: type A fractures (lower sacrococcygeal), type B fractures (postural pelvis) and type C fractures (Spinopelvic).
Each type is subdivided into 3 or 4 subtypes depending on its severity. Type A fractures (fig. 1, 2 and 3) are lesions of the lower sacro-bile spine that occur below the level of the sacroiliac joint. Because Type A fractures do not affect the weight-bearing axis or the rear ring of the pelvis, they do not affect the rear stability of the pelvis or spinopelvic. Type B fractures (Figures 4, 5 and 6) are unilateral vertical or sacred fractures in which the S1 facet superior to the ipsilateral with the middle part of the sacrum is continuous, maintaining spinopelvic stability, while the stability of the rear pelvis may be affected. Type C fractures (Figures 7 to 10) describe lesions that cause spinopelvic instability and are divided into 4 subtypes.