How many joints are traditionally observed at each lumbar vertebral body
L1-L5 = six each
What is the the inferior articular facet orientation at each lumbar vertebra?
L1-L5 = forward, downward, lateral (FoLD)
What part of the sacral all is derived from the costal element?
The anterior two-thirds
The costal element and true transverse process of sacrum unite to form what feature?
Sacral Ala
How many fibrous (Amphiarthrosis) Syndesmosis joint surfaces are present on the S1 vertebral body?
Four
How many joint surfaces are present on the vertebral body of the first sacral segment?
Five
What muscle(s) may attach to the first sacral vertebral body?
Psoas major
What is the reported angulation of the first sacral articular facets?
They lie vertically in the coronal plane
What is the position of the sacral zygapophysis in adults?
The zygapophysis lies in the coronal plane for L5/S1
What is the orientation of the first sacral superior articular facet?
Backward, upward, medial (BUM); typically concave
What is the name given to the projection on the first sacral superior articular process?
Mammillary process
From the anterior view, the intervertebral discs of sacrum will be replaced by what feature?
Transverse ridges
An imaginary line drawn along the dorsal midline of sacrum is identified as the __________.
Median sacral crest
What forms the median sacral crest?
Fused spinous processes and their spinous tubercles
What is the name given to the congenital condition in which the fifth lumbar spinous process is elongated, the sacrum exhibits spina bifida, and dorsiflexion produces pain?
Knife Clasp Syndrome
An imaginary line drawn from the superior articular process of S1 to the sacral Cornu will form what feature?
Immediate sacral crest
What forms the intermediate sacral crest?
Fused articular processes and their facets
What features may be identified along the intermediate sacral crest?
The mammillary process of S1 and the sacral Cornu of S5
What is the remnant of the inferior articular process and facet of S5?
The sacral Cornu
What is the name of the inferior opening of the sacral spinal canal?
The sacral hiatus
What forms the lateral sacral crest?
The fused transverse processes and transverse tubercles from S1 to S5
What is the sacral tuberosity?
The enlarged transverse tubercle of S2
What is the name of the joint formed by the sacral tuberosity?
The accessory sacral-iliac joint
What muscle is said to attach to the dorsal surface of sacrum?
Iliac us
What feature is identified on the lateral surface of S1-S3?
Auricular surface
What classification of joint is formed by the Auricular surface of sacrum?
Synovial plane (diarthrosis arthrodia)
What feature does the anterior surface of the superior epiphyseal rim of S1 form?
The sacral promontory
What ligament is attached to the sacral hiatus?
The superficial posterior sacrococcygeal ligament
how many synovial joints are typically present at sacrum?
Four
What joint classifications are typically present at sacrum?
Fibrous (Amphiarthrosis) Syndesmosis, cartilaginous (Amphiarthrosis) symphysis and synovial plane (diarthrosis arthrodia)
How many synovial joints are maximally observed at each lumbar vertebra?
L1-L5 = four each
What forms the posterior boundary for the fifth sacral spinal nerve intervertebral foramen?
Sacral Cornu, coccygeal Cornu, superficial posterior sacrococcygeal ligament and intercornual ligament
What forms the anterior boundary for the fifth sacral spinal nerve intervertebral foramen?
Vertebral body S5, vertebral body Co1, deep posterior sacrococcygeal ligament and intervertebral disc
What is the homologous for the posterior longitudinal ligament at S5?
Deep posterior sacrococcygeal ligament
What is the homolog for the anterior longitudinal ligament at S5?
Anterior sacrococcygeal ligament
What is the homolog for the ligament flavum at S5?
Superficial posterior sacrococcygeal ligament
What forms the inferior boundary for the spinal canal?
The Union of the superficial posterior and deep posterior sacrococcygeal ligaments
What ligaments is formed by the union of the superficial posterior sacrococcygeal and the deep posterior sacrococcygeal ligaments at Co1?
The posterior sacrococcygeal ligament
What ligament is a homolog of the intertransverse ligament at S5?
Lateral sacrococcygeal ligament
What ligament divides the sciatic foramen into the greater and lesser sciatic foramina?
Sacrospinous ligament
Which ligament has broad attachment along the lateral margin of sacrum and coccyx and then attaches to the ischia like tuberosity?
Sacrotuberous ligament
Which ligament represents a thickening of the fibrous capsule of the sacrococcygeal-iliac joint?
Anterior sacro-iliac ligament
Which ligament is the strongest of the sacro-iliac ligaments and is penetrated by the dorsal rami of the sacral spinal nerves?
Interosseous sacro-iliac ligament
Which ligament will attach the intermediate sacral crest of S1, lateral sacral crest of S2 to the posterior superior iliac spine?
Short posterior sacro-iliac ligament
Which ligament attaches the lateral sacral crest of S3 and S4 to the posterior superior iliac spine?
Long posterior sacro-iliac ligament
What is the homolog for the capsular Ligament at S5?
Intercornual ligament
What is the number of coccygeal somites?
Ten
What is the typical number of segments that unite to form the adult coccyx?
4 segments
When is ossification of coccyx completed?
About age 30
What is the direction of fusion off coccygeal segments?
From caudal to cranial, the last segments to fuse together are Co1 and Co2
What is the direction of fusion of coccygeal segments?
From caudal to cranial, the last segments to fuse together are Co1 and Co2
What is the direction of the coccygeal curve?
Posterior (Kyphotic)
What is the major motion and range of motion for coccyx?
Flexion-extension, 5-20 degrees
How many coccygeal nerves are present in the fetus?
Typically 5 pairs of coccygeal nerves are present
How many coccygeal nerves are present in the adult?
Typically only one pair of coccygeal nerves remain in the adult
What forms the coccygeal nerve plexus?
S4, S5 and Co1 nerves
What is the ganglion impar?
A midline sympathetic ganglion
What innervates the coccygeal glom us or coccygeal body?
Both sympathetic and parasympathetic fibers are identified