Anatomy of Cervical Spine and Intervertebral Disc Repair

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REVIEW OF ANATOMY OF SPINE UNDERLYING
INTERVERTEBRAL DISC REPAIR
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CERVICAL SPINE IS LOCATED IN CENTER OF NECK
SURROUNDED BY MANY STRUCTURES THAT ARE ESSENTIAL,
SMALL AND READILY DAMAGED THESE SLIDES REVIEW
THE ANATOMY OF VERTEBRAE, STRUCTURE OF THE NECK
AND SPINAL CORD TO APPRECIATE THE TECHNIQUE OF
CERVICAL DISC REPAIR
CERVICAL SPINE IS LOCATED IN CENTER OF
NECK SURROUNDED BY MANY STRUCTURES THAT ARE
ESSENTIAL, SMALL AND FRAGILE
NOSE
BODY OF CERVICALVERTEBRA
INTERVERTEBRAL DISC
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ANATOMY OF TYPICAL VERTEBRA
1. BODY anterior, solid transmits weight 2.
VERTEBRAL ARCH posterior, surrounds vertebral
canal, spinal cord consists of a) PEDICLES
project from body b) LAMINAE
unite to form arch posteriorly
anterior
NOSE
BODY
TRANSVERSE PROCESS-LATERAL

PEDICLE
VERTEBRAL ARCH
LAMINA
SPINOUS PROCESS - POSTERIOR
3. TRANSVERSE AND SPINOUS PROCESSES - projections
from arch for muscle, ligament attach
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NOSE
LATERAL VIEW OF VERTEBRA
JOINTS BETWEEN VERTEBRAE PERMIT
MOVEMENTS HOWEVER, CAN POTENTIALLY DAMAGE SPINAL
NERVES
Sup. Vertebral Notch
Inf. Vertebral Notch
2. Spinal nerves leave vertebral canal via
INTERVERTEBRAL FORAMINA - between
vertebrae bordered by Superior and Inferior
Vertebral Notches
1. Location of Intervertebral Discs between bodies
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VERTEBRA IN DIFFERENT REGIONS ARE SPECIALIZED
Cervical (neck) - 7 vertebrae (C1-C7) Thoracic
(chest) - 12 vertebrae (T1-T12) Lumbar (lower
back) - 5 vertebrae (L1-L5) Sacral (pelvis) - 5
fused vertebrae (S1-S5) Coccygeal (tail) - 3-5
vertebrae (Co1-Co3)
Vertebral column functions like
structural support column Most weight is
supported at base of column (lumbar and sacral
vertebrae are large) Cervical vertebrae are
relatively small
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CERVICAL VERTEBRA - small and highly mobile
NOSE
body is small Foramen Transversarium - in
transverse process (C1-C7) for Vertebral artery
veins
ant.
BODY
TRANSVERSE PROCESS
post.
SPINOUS PROCESS bifid (divided) for Ligamentum
nuchae
ARTICULAR FACETS - angled superiorly medially -
PERMIT CONSIDERABLE MOVEMENT
lat. view
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VERTEBRAE ARE STABILIZE BY BEING LINKED BY
LIGAMENTS, INTERVERTEBRAL DISCS
1. ANTERIOR LONGITUDINAL LIGAMENT -Strong band
joins bodies on anterior side
Adjacent vertebrae held tightly together (protect
spinal cord)
Anterior view
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VIEW FROM INSIDE VERTEBRAL COLUMN
On post. Side of bodies
LOOK ANTERIOR
LOOK POSTERIOR
2. POSTERIOR LONGITUDINAL LIGAMENT- weaker,
narrower band on posterior side of bodies
3. LIGAMENTA FLAVA - yellow elastic bands
connecting laminae
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STRUCTURE/ FUNCTION OF INTERVERTEBRAL DISC
Intervertebral discs function as shock absorbers
there are strong but undergo degeneration with
age (begins at about age 20)
a) Nucleus pulposus-inner gelatinous core
b) Anulus fibrosus - collagen fibers
fibrocartilage
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MRI OF 'SLIPPED DISK' FROM SNELL'S TEXTBOOK
POSTERIOR
ANTERIOR
HERNIATION OF NUCLEUS PULPOSUS
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DAMAGE TO INTERVERTEBRAL DISCS
Postero-lateral
POSTERIOR LONGITUDINAL LIGAMENT
post
lateral
ANTERIOR LONGITUDINAL LIGAMENT
Typically in Postero-Lateral Direction, lateral
to Posterior Longitudinal Ligament (Anterior
Longitudinal Ligament is broad and strong) Disc
herniation can lead to nerve compression at
intervertebral foramen
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DAMAGE TO CERVICAL INTERVERTEBRAL DISCS CAN
PRODUCE SYMPTOMS IN UPPER EXTREMITY
Ventral rami of spinal nerves
C5
LOWER CERVICAL SPINAL NERVES FORM BRACHIAL PLEXUS
C6
C7
C8
T1
DAMAGE TO SPINAL NERVES CAN PRODUCE SENSORY AND
MOTOR LOSS
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SENSORY LOSS - DERMATOME MAP
THUMB C6
LITTLE FINGER C8
Dermatomes of upper extremity C6 - thumb C7 -
middle finger C8 - little finger
Questions What is the level of a herniated disc
that would produce numbness of thumb? Little
finger?
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NUMBERING OF CERVICAL SPINAL NERVES
LEVELS OF SPINAL NERVES
Spinal nerves - arise from/project to spinal
cord there are 31 spinal nerves (8 cervical, 12
thoracic, 5 lumbar, 5 sacral and 1
coccygeal). Note Cervical spinal nerves 1-7
(C1-C7) exit above corresponding vertebrae
Spinal nerve C8 exits below vertebra C7 All
other spinal nerves exit below corresponding
vertebrae.
CONVENTION FOR NAMING LEVELS
Cervical (C1-C8)
Thoracic (T1-T12)
Spinal nerves C1-C7 above vertebra
Lumbar (L1-L5)
Sacral (S1-S5)
C8 and all others below vertebra
Coccygeal (Co1)
SPINAL NERVE C6 ARISES ABOVE VERTEBRA C6
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Ia sensory neuron
TESTING OF SPINAL NERVE DAMAGE - STRETCH REFLEXES
CLINICAL TESTING OF STRETCH REFLEX TENDON TAP
Alpha motor neuron
TENDON TAP
1- Tendon tap elicits twitch because it excites
almost all muscle spindles simultaneously 2- Use
stretch reflexes to test nerve function at
different spinal levels
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REFLEXES USED FOR CLINICAL TESTS
Nerve compressions can produce reduced spinal
reflexes also muscle weakness
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NECK CONTAINS A NUMBER OF VITAL STRUCTURES
SPINAL CORD
TRACHEA
COMMON CAROTID ARTERY
ESOPHAGUS
INTERNAL JUGULAR VEIN
INTERVERTEBRAL DISC
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ANATOMY OF NECK NECK IS COMPARTMENTALIZED
1. Posterior Compartment -Vertebrae and muscles
which support and move head neck 2.
Anterior Compartment- Viscera and rostral
continuation GI Respiratory Systems 3. Lateral
Compartment- Blood vessels nerve
Plane of section
ANT.
LAT.
POST.
HORIZONTAL SECTION THROUGH NECK NOTE VERTEBRAE
ARE IN CENTER OF NECK
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LOCATION OF STRUCTURES IN NECK COMPARTMENTALIZED
BY FASCIA
NOSE
Pretracheal layer
Plane of section
Carotid Sheath
Prevertebral
Layer- surrounds vert. column muscles back of
neck, prevertebral, lateral vertebral and
suboccipital m. Pretracheal Layer- surrounds
trachea, esophag. thyroid continues to
mediastinum Carotid Sheath-
surrounds common int carotid, int jugular and X
(not Symp. Chain)
LOCATION OF INTERVERTEBRAL DISC
Prevertebral layer
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DISCS ARE POSTERIOR TO PREVERTEBRAL MUSCLES
ACT - FLEX NECK/HEAD INN - CERVICAL VENTRAL RAMI
2. Longus capitis O - Trans processes C3-C6 I -
Occipital bone 1. Longus colli muscle - O- Trans
processes Lower cervical vertebrae I - Bodies
upper cervical vertebrae
Colli neck in Latin
View of anterior side of Cervical Vertebrae with
structures of Anterior and Lateral Compartments
removed
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HOW IS DAMAGE TO CERVICAL INTERVERTEBRAL DISC RE
PAIRED? SEE DR. LECLERCQ'S LECTURE
INTERVERTEBRAL DISC