Sacrococcygeal symphysis
Sacrococcygeal symphysis | |
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Details | |
Identifiers | |
Latin | articulatio sacrococcygea, symphysis sacrococcygea |
TA98 | A03.2.08.001 |
TA2 | 1688 |
FMA | 16210 |
Anatomical terminology |
The sacrococcygeal symphysis (sacrococcygeal articulation, articulation of the sacrum and coccyx) is an amphiarthrodial joint, formed between the oval surface at the apex of the sacrum, and the base of the coccyx.
It is a slightly moveable joint
Structure
Articular disc
The sacrococcygeal disc or interosseus ligament[3] is similar to the intervertebral discs[2] but thinner, thicker in front and behind than at the sides, and with a firmer texture. The articular surfaces are elliptical with longer transversal axes. The surface on the sacrum is convex and that on the coccyx concave.[2] Occasionally the coccyx is freely movable on the sacrum, most notably during pregnancy; in such cases a synovial membrane is present.
Ligaments
The joint is strengthened by a series of ligaments:
- The ventral or bodies of the vertebrae. It consists of a few irregular fibers that attach to the anterior sides of the sacrum and coccyx and blend with the periosteum.[1]
- The dorsal or posterior sacrococcygeal ligament has a deep and a superficial part:
- The deep dorsal ligament is a flat band which corresponds to the vertebral canal on the posterior surfaces of the bodies of the vertebrae. From the posterior side of the fifth sacral body inside the sacral canal, the dorsal ligament stretches to the posterior side of the coccyx, to attach deep to the superficial dorsal ligament.[1]
- The superficial dorsal ligament corresponds to the
- The deep dorsal ligament is a flat band which corresponds to the
- The foramina for the last sacral nerve.[1] Three lateral ligaments have been reported on either side.[3]
- The interarticular or cornu of the sacrum to the cornu of the coccyx.[1]
Function
Movements in the joint are restricted to
Clinical significance
The joint is
See also
- Anococcygeal raphé
- Coccydynia (coccyx pain, tailbone pain)
- Ganglion impar
- Rump (croup)
Notes
References
This article incorporates text in the public domain from page 309 of the 20th edition of Gray's Anatomy (1918)
- Morris, Craig E. (2005). Low Back Syndromes: Integrated Clinical Management. McGraw-Hill. ISBN 0-07-137472-8.
- Huijbregts, Peter A. (2001). "In: Current Concepts of Orthopaedic Physical Therapy". Lumbopelvic region: Anatomy and biomechanics (PDF). APTA.
- Masquelet, Alain C.; Christopher J. McCullough; Ian S. Fyfe; Raoul Tubiana (1993). An Atlas of Surgical Exposures of the Lower Extremity. Taylor & Francis. ISBN 1-85317-003-8. (A good illustration of the posterior and lateral ligaments.)
- Palastanga, Nigel; Field, Derek; Soames, Roger (2006). Anatomy and Human Movement: Structure and Function. Elsevier Health Sciences. ISBN 0-7506-8814-9.