5. Atlas
• Doesn’t Have body &spinous
process
• Its ring-like, has anterior and a
posterior arch and two lateral
masses.
• Each lateral mass has superior
articular facet&inferior articular
facet.
• Superior articular facet articulate
with occipital condoyle- atlanto-
occipital joint.
• Inferior articular facet articulate
with axis superior facet –atlanto-
axis joint.
• Transverse process project
laterally from lateral mass which
is pierced by foramen
transversorium
6. Attachment
• Anterior tubercle & lower border of
the anterior arch give attachment to
ant. Longitudinal ligament.
• Upper border of anterior arch gives
attachment to ant. Atlanto-occipital
membrane.
• Upper surface of posterior arch has a
groove- occupied by vertebral artery
& first cervical nerve.
• Behind the groove the upper border of
posterior arch give attachment to post.
Atlanto-occipital membrane
• Lower border of posterior arch –
highest pair of ligamenta flava.
• Posterior tubercle provide attachment
to ligamentum nuchae
• Tubercle on medial side of the lateral
mass –give attachment to transverse
lig.of atlas.
7.
8. AXIS
• The second cervical
vertebra
(C2) of the spine is named
the axis
• The most distinctive
characteristic
of this bone is the
strong odontoid
process ("dens") which
rises perpendicularly from
the upper surface of the
body
9. • Dens provide attachment at its apex to apical
ligament& on each side to alar ligament.
• Anterior surface of body gives attachment to
ant. Longitudinal ligament.
• Posterior surface of body gives attachment to
vertical limb of cruciate ligament , membrana
tectoria, post.longitudinal ligament.
10. Ligamentous Anatomy
• Anterior longitudinal ligament
– Reinforces anterior discs, limits extension
• Posterior longitudinal ligament
– Reinforces posterior discs, limits flexion
• Ligamentum nuchae = supraspinous
ligament
– Thicker than in thoracic/lumbar regions
– Limits flexion
• Interspinous/intertransverse ligaments
– Limit flexion and rotation/limits lateral
flexion
• Ligamentum flavum
– Attach lamina of one vertebrae to another,
reinforces articular facets
– Limits flexion and rotation
11.
12. Ossification centres of atlas
• C1-3 primary
ossification centre.
• One for anterior arch
&two for neural arch.
• Anterior ossification
centre appear 20% at
birth & visible by 1
year.
• Neural arch appear at
7th fetal week & fuse
with anterior arch at
7th year
• Neural arch fuse
posteriorly by 3th year
of life.
13. Ossification centres of axis
• C2-4 ossification centre.
• One for each neural arch,
body & odontoid process each
one.
• Odontoid process forms in
utero from 2 separate
ossification centre & fuse in
mid line by 7th fetal month.
• Secondary ossification centre
appear at apex of odontoid
process between 3 to 6 yrs &
fuse by 12-13 yrs.
• Body fuse with odontoid
process by 3-6yrs.
• Neural arch fuse with body of
odontoid between 3-6 yrs &
fuse posteriorly 2-3yrs.
14. C3-c6 vertebra
• The body of these four vertebrae is small, and
broader from side to side than from front to back.
• The pedicles are directed laterally and backward, and
are attached to the body midway between its upper
and lower borders, so that the superior vertebral
notch is as deep as the inferior.
• The laminae are narrow, and thinner above than
below; the vertebral foramen is large, and of a
triangular form.
• The spinous process is short and bifid, the two
divisions being often of unequal size.
• The superior and inferior articular processes of
neighbouring vertebrae often fuse on either or both
sides to form an articular pillar, a column of bone
which projects laterally from the junction of the
pedicle and lamina.
• The transverse processes are each pierced by the foramen
transversorium, which, in the upper six vertebrae, gives
passage to the vertebral artery and vein, as well as a plexus of
sympathetic nerves. Each process consists of an anterior and a
posterior tubercle. These two parts are joined, outside the
foramen.
15. Cervical Vertebra (C7)
• .Its has a long and prominent spinous process.
Its thick, nearly horizontal, not bifurcated.
Foramen transversorium may be as large as
that in the other cervical vertebrae
On the left side it occasionally gives passage
to the vertebral artery; more frequently the
vertebral vein transverses it on both sides;
but the usual arrangement is for both artery
and vein to pass in front of the transverse
process, and not through the foramen.
Sometimes the anterior root of the transverse
process attains a large size and exists as a
separate bone, which is known as a cervical
rib.
16.
17. Ossification of c3-c7
• 3 ossification centre-one
for body & 2 neural arch.
• Body fuse with neural
arch by 3-6yrs.
• Neural arch fuse
posteriorly by 2-3yrs.
• Secondary ossification
centre may be seen at
the tip of transverse
process/spinous process
and persist until early 3th
decade of life & stimulate
fracture.
24. Plain Films
• Plain films provide the quickest way to survey the cervical spine. An
Adequate spine series includes three views: a true lateral (which must
include all seven cervical vertebrae as well as C7-T1 junction), and AP view,
and an open mouth odontoid view. These three views do not require the
patient to move the neck, and should be obtained without removal of the
cervical collar.
25. POSITIONING
• AP projection :
– Patient - either erect or supine
– Center the mid-sagittal plane of
patients body to mid line of
table.
– Adjust the shoulders to lie in the
transverse plane
– Extend the neck enough so that a
line from lower edge of chin to
the base of the occiput is
perpendicular to the film.
– Central beam is directed towards
C4 VERTBRA(thyroid cartilage)
– Tube tilt- 15 to 20 degrees
cephalad.
26. • Film size-18*22cm or 24*30cm.
• Kvp-80
• Suspended expiration.
• Collimation-include the lower margin of mandible
to lung apex.
27. AP View
• The height of the cervical
vertebral bodies should be
approximately equal.
• The height of each joint space
should be roughly equal at all
levels.
• Progressive loss of disc height
uncinate process impact on
the reciprocating
fossa,producing osteophytes
• Spinous process should be in
midline and in good
alignment.
28.
29. LATERAL PROJECTION
(grandy method)
Patient position:
• Place the patient in a lateral position either
seated or standing.
• Adjust the height of the cassette so that it is
centered at the level of 4th cervical segment
• Adjust the body in a true lateral position, with
the long axis of cervical vertebrae parallel with
plane of film
Elevate the chin slightly to prevent
superimposition of mandible.
• Ask the patient too look steadily at one spot on
the wall to aid in maintaining the position of
head
• Respiration is suspended at end of full
exhalation to obtain max depression of the
shoulder.
30. Lateral view.
1) Anterior arch of atlas
2) Posterior arch of atlas
3) Dens
4)Laminae C2
5) Spinous Process C6
6) C7-T1 Intervertebral
Foramina
7) Retropharyngeal
Space (Normal < 7mm)
8) Retrotracheal Space
(Normal <2cm).
36. Hyperflexion & hyperextension views
• Used to Demonstrate normal anterioposterior movement or
fracture/subluxation or degenerative disc disease(vacuum
phenomenon).
• Spinous process are elevated and widely separated in hyperflexion.
• Depressed and closed approximation on the hyperextension
position.
38. ODONTOID VIEW
• SUPINE OR ERECT POSITION.
• ARMS BY THE SIDE.
• OPEN MOUTH AS WIDE AS POSSIBLE.
• ADJUST HEAD SO THAT LINE FROM LOWER EDGE OF UPPER
INCISORS TO THE TIP OF MASTOID PROCESS IS
PERPENDICULAR TO THE FILM
• Ask to PHONATE ah!!!!!!!!!!
39. Transoral/AP dens(peg) view
• An adequate film should include the entire
odontoid and the lateral borders of C1-C2.
• Occipital condyles should line up with the
lateral masses and superior articular facet of
C1.
• The distance from the dens to the lateral
masses of C1 should be equal bilaterally.
• The tips of lateral mass of C1 should line up
with the lateral margins of the superior
articular facet of C2.
• The odontoid should have uninterrupted
cortical margins blending with the body of C2.
40.
41. oblique(ant.&posterior)
• Patient may be erect or
recumbent.
• Patient is rotated 45 degree
to one side –to left for
demonstrating right side
neural foramina & to the
right to demonstrate left
neural foramina.
• Central beam directed to c6
vertebra(base of neck) .
• Tilt of 15-20 degree caudal
for anterior oblique&
posterior oblique 15-20
degree cephalad angulation.
42.
43.
44. job list
• NAME,AGE, SEX
• IP NO, INDICATION
• CONTOUR
• ALIGNMENT
• DENSITY
• IVDS
• LINES
• BONES
• JOINTS
• PRE AND PARAVERTEBRAL SOFT TISSUE
47. Chamberlain line
Posterior margin of hard
palate to posterior
margin of foramen
magnum(opisthion)
The odontoid process
should not project
above this line more
than 3mm.
48. Mc Gregor line
Line is drawn from
posterosuperior margin of
the hard plate to most
caudal part of the
occipital curve of the
skull.
Tip of odontoid normally
don’t extend more than
4.5mm above this line.
49. Mc Rae line
Line connects the basion
with opisthion of
foramen magnum.
Odontoid process should
be just below this line
or the line may intersect
only at the tip of
odontoid process.
50. Ranawat method
Coronal axis of c1 is determined
by connecting centre of the
anterior arch of c1 vertebra
with its posterior ring.
Centre of sclerotic ring in
c2,represent pedicle, is marked.
Line drawn along the axis of
odontoid process to first line.
Normal distance between c1-c2
men-17mm women-15mm(+/-
2SD)
Decrease in distance indicate
cephalad migration of c2.
51. - identifies anterior subluxation & is described as ratio of
BC/OA
- BC is the distance from the basion to the midvertical
portion of posterior laminar line of the atlas;
- OA is distance from opisthion to midvertical portion
of posterior surface of anterior ring of Atlas;
- if this ratio is greater than 1, anterior subluxation
exists;
POWERS RATIO
52. Plain film and CT demonstration of measuring
the Powers ratio. If the Power's Rule (BC)/(AO)
is greater than 1 then anterior occipitoatlantal
dislocation has likely occurred
53. HARRIS LINES
• Have also been referred to as the BDI/BAI or the Rule of
Twelve. The basion-posterior axial line interval (BAI) is drawn
along the posterior aspect of the dens (the posterior axial
line) and a measurement between this line and the tip of the
basion is performed.
The basion-dental interval (BDI) is the distance measured
between the tip of the basion and the tip of the dens.
When the the BDI and BAI to be greater than 12 mm then
occipitoatlantal dissociations has occurred.
•
It is believed to be the useful, sensitive, radiographic
parameters for detecting and characterizing
occipitocervical dissociation .
54. Sagittal CT images: Left measures the basion-posterior axial line interval which is denoted by
the small horizontal red line. The right image demonstrates measurement of the basion-
dental interval which is denoted by the vertical red line. If either of these distances are
greater than 12 mm then the diagnosis of occipitocervical dislocation is fairly certain.
55. • Wachenheim clivus line
• A line drawn along
posterior aspect of
clivus towards odontoid
process.
• Abnormality is
suspected when this
line does not intersect
or is tangential to
odontoid process.
58. • ALSO CALLED UNUNITED SUMMIT EPIPHYSIS,
BERGMANN OSSICLE
• SECONDARY OSSIFICATION CENTRE APPEARS AT
2yrs & FUSION OCCURS BY 12-13yrs
• C/F: ASYMPOMATIC , BRAIN STEM FEATURES
OCCURS WHEN TRANSVERSE LIGAMENTT
DISLOCATES INTO THE CLEFT
• INCREASED INCIDENCE IN DOWN SYNDROME
• V SHAPED CRESENT
• 3-5 mm , OVOID , DIAMOND SHAPE
61. • ALSO CALLED UN UNITED ODONTOID PROCESS
• IT’S A NON-UNION OF DENS WITH AXIS BODY
• 3-6yrs NORMAL OSSIFICATION
• ASSOCIATED WITH DOWN SYNDROME, ATLAS HYPOPLASIA, KLIPPEL-FIEL
SYNDROME, SKELETAL DYSPLASIA
• AUDIBLE CREPITUS, SUBOCCIPITAL PAIN
• R/F: ALTERED SHAPE OF ANTERIOR ARCH OF ATLAS (HYPERTROPHY) , ADI
IS NORMAL,
63. • Description: Disruption of the
atlanto-occipital junction involving
the atlanto-occipital articulations.
Mechanism: Hyperflexion or
hyperextension.
Radiographic features:
1. Malposition of occipital condyles in
relation to the superior articulating
facets of the atlas.
2. Cervicocranial prevertebral soft
tissue swelling.
Stability: unstable
64. Atlanto-axial dislocation
• AD interval –distance between
anterior surface of dens &
posterior surface of anterior
arch of c1.
• Atlanto axial instability is
define as increase AD interval
of >3mm (adult)
&>5mm(children).
• Symptoms presents when the
atlas moves forward on the
axis to narrow the spinal canal
& impinge on the spinal cord.
• Almost all atlanto-axial
dislocation involve forward
movement of c1 on
c2;posterior dislocation is rare.
67. Jefferson Fracture
• Description: compression fracture of the bony ring of C1, characterized by
lateral masses splitting and transverse ligament tear.
• Mechanism: axial blow to the vertex of the head (e.g. diving injury)
• Radiographic features: in open mouth view, the lateral masses of C1 are
beyond the body of C2. A lateral displacement of >2mm or unilateral
displacement may be indicative of a C1 fracture. CT is required to define
extent of fracture.
• Stability: unstable
68. Jefferson fracture
A Jefferson fracture is a bone fracture occurring at the first vertebrae. It is
classically described as a four-part break that fractures the anterior and posterior
arches of the vertebra, though it may also appear as a three or two part fracture.
69. Odontoid Fractures
• Three types:
– Type I - fracture in the superior tip of the odontoid. (rare)
– Type II - fracture is at the base of the odontoid. It is the most common
type of odontoid fracture and is UNSTABLE.
– Type III fracture through the body of the axis. Has the best prognosis.
70.
71. Hangman’s Fracture
• Description: fractures through the pedicle of the axis.
• Mechanism: hyperextension (e.g. hanging, chin hits dashboard in MVA)
• Radiographic feature: best seen on lateral view
– prevertebral swelling
– Anterior dislocation of the C2 vertebral body
– bilateral C2 pedicle fractures
72. • Type 1-fracture
through the pedicle of
c2.
• Type 2-
type1+concomitant
disruption of
intervertebral disc c2-
c3.
• Type 3-type2+c2-c3
facet dislocation.
73. Flexion Teardrop Fracture
• Description: posterior ligament disruption and anterior compression fracture
of the vertebral body.
• Mechanism: hyperflexion and compression (e.g. diving into shallow water)
• Radiographic feature: Teardrop fragment from anterior vertebral body,
posterior body sublux into spinal canal
74. Anterior Subluxation
• Description: disruption of the posterior ligamentous complex. Difficult to
diagnose. Subluxation may be stable initially, but it associates with 20-50%
delayed instability.
• Mechanism: hyperflexion
• Radiographic feature: best seen on flex/ext
– anterior sublux of more than 4mm
– fanning of interspinous ligaments
– loss of normal lordosis
75. Clay Shoveler’s Fracture
• Description: fracture of a spinous process C6-T1.
• Mechanism: powerful hyperflexion, usually combined with contraction of
paraspinal muscles pulling on the spinous process.
• Radiographic feature: best seen on lateral
– spinous process fracture
– ghost sign on AP (i.e.. Double spinous process of C6 or C7 resulting from displaced
fractured process)
77. Burst Fracture
• Description: fracture of C3-C7 that results from axial compression. Injury to
the spinal cord, secondary to displacement of posterior fragments, is
common. CT is required to define extent of injury.
• Mechanism: axial compression
• Radiographic features: best seen on CT
78.
79. Unilateral Facet Dislocation
• Description: facet joint dislocation and rupture of the hypophyseal joint
ligaments.
• Mechanism: simultaneous flexion and rotation
• Radiographic features: best seen on lateral and oblique
– Anterior dislocation of affected vertebral body by less than half of the vertebral
body AP diamete
– widening of the disc space
80.
81. Bilateral Facet Dislocation
• Description: complete anterior dislocation of the vertebral body. It is
associated with a very high risk of cord damage.
• Mechanism: extreme flexion of head and neck without axial compression
• Radiographic feature: best seen on lateral
– complete anterior dislocation of affected body by half or more of the vertebral
body AP diameter.
– “Bow tie” or “Bat wing” appearance of the locked/jumped facets.
