Bone
Sacrum
Five fused vertebrae
High-yield
Anterior (pelvic) and posterior sacral foramina transmit the sacral nerve rami; the sacral hiatus is used for caudal epidural anesthesia.
Overview
A triangular bone formed by five fused sacral vertebrae that wedges between the hip bones to transmit weight to the pelvis.
Reference facts
- Bone type
- Irregular (fused)
- Key landmarks
- Sacral promontory; Ala; Anterior and posterior sacral foramina; Median sacral crest; Sacral hiatus; Auricular surface
- Articulations
- L5 vertebra; Hip bones (sacroiliac joints); Coccyx
Frequently asked questions
What type of bone is the sacrum?
The sacrum is an irregular (fused) bone.
What does the sacrum articulate with?
The sacrum articulates with the L5 vertebra; Hip bones (sacroiliac joints); Coccyx.
What are the key landmarks of the sacrum?
Key landmarks of the sacrum include the sacral promontory; Ala; Anterior and posterior sacral foramina; Median sacral crest; Sacral hiatus; Auricular surface.