Ch. 8 C & T Spine
C2-T12 Intervertebral Joints
*cartilaginous (symphesis) *Amphiarthrodial (slightly movable)
*JOINT MOVEMENTS* C1 (skull) -occipitoatlantal joint
*synovial *diarthrodial *ellipsoid
C1-C2 Medial atlantoaxial joint
*synovial *diarthrodial *pivot
C1-C2 R & L lateral atlantoaxial joint
*synovial *diarthrodial *plane/gliding
T1-T10 Costotransverse joints
*synovial *diarthrodial *plane/gliding
T1-T12 Costovertebral joints
*synovial *diarthrodial *plane/gliding
C2-T12 Zygapophyseal joints
*synovial *diarthrodial *plane/gliding
Zygapophyseal Joints
- 4 articular processes project from the area of junction of the pedicles & laminae -Facet: used interchangeably with Z-joint--- & only articulating surface . * Z-joints, also called "apophyseal joints"
4 unique characteristics of cervical vertebrae:
- Bifid spinous process - Articular pillar - Three foramina -Transverse foramen
Costal Joints
- Where the 12 ribs articulate with transverse processes & vertebral bodies.
What does each thoracic vertebrae have?
- a full facet or *two partial facets*, called *demifacets* on each side of the body.
What passes through the intervertebral foramen?
- between every two vertebrae, are two intervertebral foramina, one on each side, that allow spinal nerves & blood vessels to pass through
Sacrum & Coccyx
- develop as multiple separate bones, then fuse into 2 distinct bones. -newborns have 5 sacral segments & 3-5 coccygeal segments
How many processes are on each typical vertebrae?
-2 transverse processes -1 spinous process -4 articular processes
Cervical Zygapophyseal Joints
-2nd-7th cervical vertebrae -located at right angles ( 90 degrees) -C1 & 2 Z-joints are only visualized in the AP open mouth projection
DISTINGUISHING FEATURES: All cervical vertebrae:
-3 foramina each -more dominant articular pillars
The first compensatory curve is....
-A cervical curvature - concave & lordotic
The second compensatory curve is...
-A lumbar curvature - concave & lordotic
The first primary curve is....
-A thoracic curvature - convex
Intervertebral Joints:
-Amphiarthrodial -found between vertebral bodies -tightly bound for adjacent vertebral bodies for spinal stability. - allow flexibility & movement
Cervical Intervertebral Foramina
-Intervertebral foramina are suited at a 45 degree angle to the midsagittal plane & 15 degrees inferior angle because shape/overlapping -Therefore, need a 45 degree oblique position, combined with a 15 degree cephalad angle of x ray beam
Atlas : C1
-Name derived from Greek God who bore the world on his shoulders -No body, but does have an anterior arch, that includes a small anterior tubercle.
DISTINGUISHING FEATURES: C1: Atlas
-No BODY! But, *anterior & posterior arches* -NO SPINOUS PROCESS, but *posterior tubercle with Bifid tip* -lateral masses (articular pillars) -superior facets for occipitoatlantal articulations
The spinal chord which is enclosed & protected by the _____ ______, begins with the ______ _______.
-Spinal Column -medulla oblongata
Atlas: C1 Superior articular processes:
-Superior facet: to the left and right of the superior articular processes & are large depressed surfaces
Axis: C2
-The most distinctive feature of the second cervical vertebra, the axis, is the clinically important *dens* or *odontoid process* which projects from the body
Superior perspective of cervical vertebrae:
-Transverse foramen: hole in each transverse process -3 foramina that run vertically - The spinous process of C2 through 6 are fairly short & end in *bifid tips*
Characteristics of Cervical Vertebrae
-Transverse foramina -Bifid spinous process tip -Overlapping vertebral bodies
A typical vertebrae contains:
-Vertebral arch -Vertebral foramen -Body
Occipitoatlantal Joints: of ATLAS C1
-articulations between C1 & the occipital condyles of the skull. -Transverse processes of C1 are smaller but still contain the transverse foramina.
What are the 5 sections of the vertebral column?
-cervical vertebrae -thoracic vertebrae -lumbar vertebrae -sacrum -coccyx
DISTINGUISHING FEATURES: C2: Axis
-contains odontoid process (Dens)
Intervertebral Disks
-provides a cushion between vertebrae to help absorb shock -Consists of the *annulus fibrosus* & *nucleus pulposus*
Distinctive features of thoracic vertebrae:
-rib articulations (facets & demifacets) -caudally pointed spinous processes
Atlas: C1 -Articular pillars
-segments of bone between the superior & inferior articular processes, are called lateral masses for C1. -Because lateral masses of C1 support the weight of the head & assist in rotation of the head, they are the most bulky portions of C1.
DISTINGUISHING FEATURES: C2-C6:
-short spinous processes with Bifid tips
How are costotransverse joints formed?
-when the first 10 ribs arch posteriorly from the upper 10 vertebral bodies, & the tubercle of each rib articulates with one transverse process.
How many thoracic vertebrae does a human have?
12
On the anterior oblique position (LAO/RAO) for the c-spine what CR angle is needed & what is seen on the X-ray?
15 degrees caudal LAO: left foramina seen RAO: right foramina seen
On the posterior oblique position (LPO/RPO) for the c-spine what CR angle is needed & what is seen on the X-ray?
15 degrees cephalad CR angle LPO= right foramina seen RPO= left foramina seen
What forms the vertebral arch in vertebrae?
2 pedicles & 2 laminae
How many lumbar vertebrae does a human have?
5
How many Cervical Vertebrae does a person have?
7
What angle does the patient need to open the Z-Joints on a oblique T-Spine?
70-75 degree oblique position. With a perpendicular CR
Whiplash may cause:
A fracture of the dens *any fracture of the vertebral column at this level could result in serious damage to the spinal chord as well.
The second primary curve is..
A sacral curvature & Convex
Kyphosis definition:
An abnormal condition characterized by "increased convexity of the thoracic spine curvature"
What's scoliosis?
An exaggerated "lateral" curvature of the spine
Lateral perspective of cervical vertebrae:
Articular pillar (or lateral mass when referring to C1) = bone is more supportive than the similar area in the rest of the spinal column
A typical vertebrae consists of what two parts?
Body & Vertebral arch
The 7 cervical vertebrae:
C1 : Atlas C2 : Axis C3-6 : typical cervical vertebrae
Cervical Landmarks
C1: Mastoid process (C1 is 1" below the level of the EAM) C3: Gonion (angle of jaw) C4-C6: thyroid cartilage C5: (Adams Apple) C7: vertebra prominens
The 7 C-spine vertebrae
C1: atlas C2: axis C3-6: typical cervical vertebrae C7: vertebrae prominens
DISTINGUISHING FEATURES: C7:
Called *vertebrae prominens* because of its long spinous process.
How many bones are in the adult/child vertebral column?
Child: 33 Adult: 26
DISTINGUISHING FEATURES: T1-T9:
Contain demifacets for rib articulation
DISTINGUISHING FEATURES: All Thoracic Vertebrae
Contain facets for rib articulation (facets or demifacets)
DISTINGUISHING FEATURES: T1-T10:
Contain facets on transverse processes for rib articulations
DISTINGUISHING FEATURES: T10-T11:
Contain single facet for rib articulation
Lordosis:
Exaggerated lumbar curvature "Swayback" -increased concavity
Kyphosis:
Exaggerated thoracic curvature "Humpback" -increased convexity
What's an important distinguishing feature of all thoracic vertebrae?
Facets for rib articulation
In addition to costovertebral joints, what do the first 10 thoracic vertebrae have?
Facets, (one on each transverse process) that articulate with the tubercles of ribs 1-10. These articulations are termed: *costovertebral joints*
In order for the L & R thoracic foramina to be superimposed, which way should your patient be positioned?
In a lateral position, because the foramen are located at 90 degrees to the midsagital plane
What are the 3 joints in the vertebral column?
Intervertebral Zygapophyseal Costal
On the oblique view of the T-spine, what's on each side/ between any thoracic vertebrae?
Intervertebral foramina - which are defined on the superior & inferior margins by the pedicles.
On the anterior oblique position (LAO/RAO) for the T-spine what CR angle is needed & what is seen on the X-ray?
LAO: left z-joints RAO: right z-joints
On the posterior oblique position (LPO/RPO) for the T-spine what CR angle is needed & what is seen on the X-ray?
LPO: right Z-joints RPO: left Z-joints
What projection can you see open zygapophyseal joints:
Left lateral of the C-spine
The 3rd joint between C1 & C2 is called the :
Medial atlantoaxial joint *synovial *diarthrodial *pivot
Relationship of C1-2 cont.
Normally articulations between C2 & C1, the atlantoaxial joints, are symmetric. -The relationship of the dens to C1 also must be perfectly symmetric *Injury/ improper positioning can render areas for being asymmetric. *Rotation of the skull* can alter the symmetry of the spaces/joints, thus imitating an injury.
What projection do you see intervertebral foramina on?
Oblique projection of the C-spine
Define lordosis:
Refers to an abnormal anterior "concavity" of the cervical & lumbar spine
What function to live wouldn't occur without the spine?
Respiration
By knowing the facet arrangement how can you predict the rib distribution of the thoracic vertebrae?
Rib 1 articulates with T1 ONLY. Rib 2 articulates with T1 & T2, & so forth. Ribs 11 & 12 articulate ONLY with T11 & T12
What are the first two joints between the inferior articular surface of C1 & the superior articular surface of C2 called?
Right & Left lateral atlantoaxial joints *synovial *Diarthrodial *Plane/gliding
In an LPO position for the T-Spine, which side (L/R) joints will be open?
Right Z-joints will be open
What forms intervertebral foramina?
Superior & Inferior vertebral notches
What kind of facet does each rib have?
T1: A full facet & a demifacet T2-T8: demifacets on their upper & lower margins T9: one demifacet on upper margin T10-12: have full facets
Which vertebrae are considered typical thoracic vertebrae?
T5, T6, T7, & T8 *The upper 4 thoracic vertebrae are smaller and share features of the cervical vertebrae. The lower 4 share characteristics of the lumbar vertebrae.*
Axis : C2 Dens
The dens is actually the body of C1, but fuses to C2 during development; therefore considered part of C2 in mature skeletons. - Rotation of the head primarily occurs between C1 & C2, with the *dens* acting as a pivot
What's a unique characteristic of the thoracic region?
The long spinous process is projected so far inferiority, as it is BEST seen on the *lateral view*
Relationship of C1-2
The relationship of C1 to the base of the skull is clinically important because injury this high in the spinal chord can result in paralysis/death.
What is seen on the oblique views of the T-spine?
The superior & inferior articular processes are shown to connect the successive thoracic vertebrae to form, the *Zygapophyseal joints.*
What curves begin after birth?
The thoracic & sacral curves. Or The primary curves
What makes T11 & T12 different from T1-T10?
They do not show facets on the ends of the transverse process for rib articulation. ** ONLY articulate with costovertebral joints**
What are intervertebral discs?
Tough fibrocartilaginous disks separate typical adult vertebrae. -provide stability & allow flexibility & movement if the vertebral column
The posterior surface of the body & arch form a circular opening, called the ____ _____.
Vertebral foramen, which contains the spinal chord
How is the costovertebral joint formed?
When each facet or combination of two demifacets accepts the head of a rib.
Intervertebral Foramina
When the moon shaped superior & inferior vertebral notches are stacked & form a single opening called the intervertebral foramen.
Use of higher kV & thick or dense tissue results in...
increased production of scatter radiation, which degrades the image