SACRUM-DORSAL SURFACE

SUMMARY

1. Convex surface, rough.

2. In the midline, it is enclosed by fusion of the laminae.

3. The sacral canal is enclosed above by the ligamentum flavum arising from the L5 lamina.

4. The sacral hiatus is due to failure of fusion of S5 lamina, enclosed by the sacrococcygeal ligament.

5. Median sacral crest: fusion of adjacent spinous processes.

6. Intermediate sacral crest: fusion of the sacral articular processes. This ridge ends in the rounded sacral cornu, for articualtion with the coccyx.

7. Lateral sacral crest: fusion of the sacral TP, these are lateral to the sacral foramina.

8. The post-auricular surface is the weight-bearing portion of the sacrum.


Image: Case courtesy of OpenStax College, Radiopaedia.org. From the case rID: 42764.

Reference(s)

R.M.H McMinn (1998). Last’s anatomy: regional and applied. Edinburgh: Churchill Livingstone. Get it on Amazon.
Drake, Richard L., et al. Gray's Anatomy for Students. Elsevier, 2023. Get it on Amazon.