Apr 13, 2023 · The sacral vertebrae are represented by segments S1 through S5 and located between the lumbar vertebrae and the coccyx (tailbone)—the lowest part of the vertebral column.

Mar 7, 2019 · Lumbarization of S1 or lumbarization of first sacral vertebra is a condition in which the first sacral vertebra is not completely attached to its fused sacral components but instead this first sacral vertebra appears like the other lumbar vertebrae.

Nov 1, 2024 · The sacrum consists of five fused sacral vertebral and costal segments (S1-S5) that form a central sacral body and paired sacral alae (singular ala), which arise laterally from S1.

The posterior quarter of the ala represents the transverse process, and its anterior three-quarters the costal process of the first sacral segment. Each ala also serves as part of the border of the pelvic brim. The alae also form the base of the lumbosacral triangle. The iliolumbar ligament and lumbosacral ligaments are attached to the ala.

Feb 19, 2025 · Body of 1st Sacral vertebra The first sacral vertebral body is the largest of the sacral segments. It bears significant axial loads and forms the superior portion of the sacrum.

Dec 27, 2021 · The sacrum is a large, flat, triangular-shaped, irregular bone, alternatively known as the sacral vertebra or sacral spine. It comprises five fused vertebrae (S1-S5), located at the base of the vertebral column or spine.

Mar 2, 2025 · Anomalous Lumbosacral Anatomy Some variations of the lower lumbar spine and sacrum occur. The first sacral segment may be partially or completely separate – so-called lumbarization of the sacrum. Similarly, the lowest lumbar vertebra may be partially or completely fused to the sacrum – known as sacralization of the lumbar spine.

Five radiographic features (upper sacral segment not recessed in the pelvis, mammillary bodies, acute alar slope, residual S1 disk, and misshapen sacral foramen) were used to identify dysmorphic characteristics, and sacra with four or five features were classified as dysmorphic.

S1 pedicle morphology and angulation in the first sacral segment are different from the normal in L5-S1 transitional situations and hence should be mapped accordingly in screw placements at the region in context of such common variations. S1 pedicles …

Aug 15, 2011 · Objective: Measurement of parameters of the S1 pedicle and its orientation in sacra with (1) Accessory L5-S1 articulations, (2) Sacralisation of the L5, and (3) Lumbarisation of the first sacral segment, and comparing data with that observed in normal sacra.