Sacrum and coccyx (Latin)

An anterior and posterior view of the os sacrum and os coccygis. The symphysis lumbosacralis is formed between the vertebrae L5 and S1. It consists of two separate articulations: the symphysis intervertebralis anterius formed by the L5/S1 discus intervertebralis and the two articulationes zygapophysiales posterior between their processus articulares. The symphysis lumbosacralis is strengthened and stabilised by the ligg. iliolumbale and ligg. lumbosacrales. The linea transversae located on the anterior or pelvic surface of the os sacrum indicate the site of fusion of each sacral vertebra. The articulatio sacroiliaca is formed by the synovial articulation between the os sacrum and os ilium anteriorly and by the syndesmoses between their tuberosities posteriorly. The articulatio sacroiliaca is stabilised by the ligamenta sacroiliaca anteriora, interossea and posteriora. An discus intervertebralis lies between the apex ossis sacri and basis ossis coccygis to form the secondary cartilaginous junctura sacrococcygea. Reinforcing this joint are the ligamenta sacrococcygea posteriora superficiale, posteriora profundum, anteriora and laterales, as well as the ligamenta sacrotuberale and sacrospinale. Stabilising the art. intercoccygea, which are frequently fused inferiorly, are the sacral portions of the ligamentum sacrospinale and ligamentum longitudinale anterius as well as the ligamenta sacrococcygea anteriora and laterales.