Sacroiliac Joint
Description
General
- Large, auricular-shapred, diarthrodial synovial joint
- Largest axial joint in the body
- Formed by the interaction of the Sacum and Ilium
- Roughly anterior 1/3 of these two bones represents articulation
Ligaments
- The rest is composed of complex set of ligamentous connections
- Primarily: anterior and posterior interosseous ligaments
- Accessory iliolumbar, sacrotuberous, and sacrospinous ligaments
- Ligamentous stability
- Stabilized by posterior sacroiliac ligament, sacrospinous ligament, sacrotuberous ligament
- Cephalad portion of the posterior joint contains the interosseous ligament and is not a true joint capsule
Muscular support
- Supported by a network of muscles including
Actions
- Primary action is stability of trunk and lower extremities
- Transfer of load between trunk and lower extremities
- Limits rotation in the transverse axis
- Facilitates parturition (child birth)
- Limited mobility, allowing for only about 2 degrees of motion in each plane[4]
Vascular Supply
Innervation
- Somewhat controversial
- Sacral Plexus: Lateral branches of dorsal rami of L4-S3
Clinical Significance
See Also
References
- ↑ Image courtesy of https://teachmeanatomy.info/, "The Sacroiliac Joint"
- ↑ Image courtesy of https://3dmusclelab.com/, "Exploring The Sacroiliac Joint
- ↑ Ashby, Kara, et al. "Ligaments stabilizing the sacrum and sacroiliac joint: a comprehensive review." Neurosurgical Review 45.1 (2022): 357-364.
- ↑ Vlemming A, Schuenke MD, Masi AT, et al. The sacroiliac joint: an overview of its anatomy, function and potential clinical implications. J. Anat. 2012; 221:537–67.