BBaassiicc IInnttrroodduuccttiioonn iinn SSppiinnee 
((UUnnddeerrssttaannddiinngg SSppiinnee PPrroobblleemmss)) 
DDrr.. MMoohhaammeedd MMoohhii EEllddiinn ,, MB-BCH , M.Sc., MD 
PPrrooff.. ooff NNeeuurroossuurrggeerryy,, 
FFaaccuullttyy ooff MMeeddiicciinnee,, 
CCaaiirroo UUnniivveerrssiittyy 
CCoonnssuullttaanntt NNeeuurroossuurrggeeoonn 
Basic Spine Course 04/01/2010
Introductory Spine Anatomy 
Course 
• IInnttrroodduuccttiioonn ttoo AAnnaattoommyy 
• BBaassiicc VVeerrtteebbrraall SSttrruuccttuurreess 
• JJooiinnttss aanndd LLiiggaammeennttss 
• MMuusscclleess aanndd NNeerrvveess 
• VVaassccuullaarr ssttrruuccttuurreess 
• AAddddiittiioonnaall oorrggaannss aanndd ssttrruuccttuurreess
OUR AIM 
• To be familiar with 
spine anatomy 
• To be spine-minded 
• To understand 
pathological spine 
diseases 
• To correlate 
symptoms and signs 
• To facilitate surgical 
skills
Anatomical Planes 
• Anatomical position 
• Anatomical planes 
• Coronal (Frontal) Plane 
divides the body into front 
and back sections 
• Sagittal Plane divides the 
body into left and right 
sections 
– Median - divides the body 
into equal left and right 
parts 
• Axial (Horizontal or 
Transverse) Plane - divides 
the body into upper and lower 
segments
A-P X-ray of a 
scoliotic spine in 
the coronal plane. 
The CORONAL PLANE, also 
called the FRONTAL PLANE, is a 
vertical cut that divides the body 
into front and back sections. 
Surgeons look at the coronal plane 
when they view an A-P (anterior-posterior) 
x-ray of the spine to 
evaluate scoliosis. 
Anatomical Planes
Lateral X-ray of a 
kyphotic spine in 
the sagittal 
plane. 
Anatomical Planes 
The SAGITTAL or MEDIAN 
PLANE is a vertical cut that 
divides the body into left and right 
sections. The sagittal view is seen 
by surgeons on a lateral x-ray of 
the spine.
Anatomical Planes 
CT Scan of a 
thoracic vertebra 
in the axial plane. 
The AXIAL or TRANSVERSE 
PLANE is a horizontal cut that 
divides the body into upper and 
lower sections. To best view the 
axial plane of the spine, surgeons 
will often obtain a CT scan with 
axial cuts.
Basic Terminology 
• Medial - towards the midline 
• Lateral - away from the 
midline 
• Proximal - closer to a point of 
reference (extremity) 
• Distal - farther from a 
reference point (extremity) 
• Superior - upper part or above 
a specific location 
• Inferior - lower part or below 
a specific location 
Lateral 
Medial 
Proximal 
(closer to) 
Distal 
Superior to 
Inferior (farther from) 
to 
Additional terms used in describing 
anatomical positions or locations:
• Cranial - the head or towards 
the head Cranial 
Caudal 
Anterior 
Posterior 
Dorsal 
Ventral 
• Caudal (tail) - the tail or 
towards the tail 
• Anterior - the front section or 
towards the front 
• Posterior - the back section 
or towards the back 
• Ventral - the front or anterior 
surface 
• Dorsal - the back or posterior 
surface 
Basic Terminology
YYoouurr TTuurrnn!!
Your Turn: Anatomical Planes 
Name the 
Planes 
Axial 
Sagittal 
Corona?l 
? 
?
Your Turn: Basic Terminology 
Medial 
Proximal 
Distal 
Closer to the midline? 
Above? 
Superior to 
Inferior to 
Below ? 
Closer to? 
Further from? 
Away from the Lmaidtleinrea?l Name the 
Positions
Your Turn: Basic Terminology 
Caudal 
Name the 
Directions 
Anterior 
Posterior 
Dorsal 
Anterior 
surface? 
Towards the head? 
Towards the tail? 
Ventral 
Towards 
the front ? 
Towards the back? 
Posterior Surface? 
Cranial
FFuunnccttiioonnss ooff tthhee SSppiinnee 
In addition to the thirty-three vertebrae, the skull and the 
pelvis should be considered part of the spine. This is well noted in 
scoliotic patients when a full length x-ray of the spine with skull 
and pelvis is taken to evaluate the balance of the patient. 
The spine is responsible for:
Functions of the Spine 
• Protection of 
– spinal cord and nerve roots 
– internal organs
Functions of the Spine 
• Flexibility of motion in six degrees of freedom 
Flexion and Extension Left and Right Rotation 
Left and Right 
Side Bending
Functions of the Spine 
To achieve these functions, the spine 
must have: 
• Resistance to axial loading forces, 
accomplished by: 
–Kyphotic and lordotic sagittal plane curves 
–Increased mass of each vertebra from 
C1 to the sacrum 
•Elasticity accomplished by: 
–Alternating lordotic and kyphotic curves 
–Multiple MOTION SEGMENTS
The Motion Segment 
• The FUNCTIONAL UNIT of the spine 
• Composed of: 
– Two adjacent 
vertebrae 
– The intervertebral disc 
– Connecting ligaments 
– Two facet joints and 
capsules
YYoouurr TTuurrnn!!
Your Turn: Functions of the Spine 
The spine provides protection of the spinal ________, 
cord 
_________, and ___________. 
nerve roots internal organs 
The spine is flexible in 
____six degrees of freedom. 
The ____________ motion segment 
is the 
functional unit of the spine.
RReeggiioonnss ooff tthhee SSppiinnee
Regions of the Spine 
• Line of gravity 
Auricle of the ear 
Odontoid process (C2) 
Body of C7 
Anterior to thoracic 
spine 
Posterior to L3 
Femoral head
Regions of the Spine 
• Axial position of the spine by region 
Cervical - slightly anterior to the line 
of gravity 
Thoracic - significantly posterior 
Lumbar - middle of the body 
Sacrum - projects posteriorly
Sagittal Plane Curves 
In the coronal plane, the spine is straight. A lateral 
curve of the spine in the coronal plane is termed 
SCOLIOSIS. When viewed in the sagittal plane, the 
normal adult spine has four curves. There are two 
KYPHOTIC curves and two LORDOTIC curves. 
KYPHOSIS: A curvature in the sagittal plane with 
anterior concavity (concavity towards the front). The 
spine has a thoracic kyphosis and sacral kyphosis. 
LORDOSIS: A curvature in the sagittal plane with 
posterior concavity (concavity towards the back). The 
spine has a cervical lordosis and a lumbar lordosis.
Sagittal Plane Curves 
Cervical Lordosis 20°- 40° 
Thoracic Kyphosis 20°- 40° 
Lumbar Lordosis 30°- 50° 
Sacral Kyphosis
Sagittal Plane Curves 
• Primary Curves 
In a fetus, the spine has a continuous 
curvature of kyphosis like the letter “C.” This 
involves all spinal regions, but only the 
thoracic and sacral areas remain kyphotic 
throughout life. These kyphotic curves are 
considered to be PRIMARY CURVES.
Sagittal Plane Curves 
• Secondary Curves 
Lordotic curves are the 
spine’s response to weight 
bearing. When a child is two to 
three months of age and has 
sufficiently developed the 
posterior neck muscles, he 
becomes able to raise his head 
and keep it balanced over his 
shoulders. Correspondingly, the 
spine develops a lordotic curve in 
the cervical region.
Sagittal Plane Curves 
• Secondary Curves 
At about one year of age, as the child 
begins walking, he develops a lordosis in the 
lumbar spine. Cervical and lumbar lordoses 
are considered to be SECONDARY 
CURVES because they develop in 
response to weight bearing. The purpose of 
these secondary curves is to keep the spine 
balanced in the sagittal plane and reduce 
the workload of the posterior spinal 
musculature.
YYoouurr TTuurrnn!!
Your Turn: Regions of the Spine 
cervical lumbar 
The _______ and _______ regions of the 
spine have lordotic curves. 
thoracic sacral 
The _________ and ______ regions of the 
spine have kyphotic curves. 
A fetus has a C-shaped or kyphotic 
_p_rim__ar_y_ curve. 
Secondary curves develop in the 
__c_er_v_ic_a_l and __lu_m_b_a_r_ regions.
TThhiiss ccoonncclluuddeess 
IInnttrroodduuccttiioonn ttoo AAnnaattoommyy.. 
TThhaannkk YYoouu!!
Introductory Anatomical Overview
The Spine is a building 
• The vertebral bodies (Osseous spinal column) are the building 
blocks of the spine. 
• There are 7 cervical, 12 thoracic, 5 lumbar vertebral bodies 
and 5 fused sacral segments 
C1 (atlas) : anterior arch, posterior arch, and paired lateral 
masses * 
C2 (axis) : bony projection which articulate with C1 (odontoid 
process or dens) 
C3 ~ C7 : dorsolateral margin of the superior endplate 
(uncinate process)
Typical cervical, thoracic, and lumbar 
vertebra 
• Anterior body, 
• paired pedicles, articular pillars and laminae, and 
• a single dorsal midline spinous process 
• Spinous process – serve as a attachment point for the posterior 
ligamentous structures 
• Pedicle, articular pillars, and lamina - serve to protect the spinal 
cord and nerve roots 
• Transverse process 
in the mid-cervical : vertebral artery, osseous transverse foramina 
in the thoracic and lumbar spine : spinal column protect stabilize 
muscle
BBaassiicc VVeerrtteebbrraall SSttrruuccttuurreess 
Cervical Thoraci 
c 
Lumbar 
All vertebrae are formed according to the same basic structures, and 
the same nomenclature can be applied to all regions of the spine. Only the 
first and second cervical vertebrae are distinct in structure. This section 
reviews the basic structures common to all vertebrae. Previously we 
identified the four regions of the spine. Now we will examine the bony 
structures common to each region.
Types of Bone Tissue 
There are two types of bone tissue: 
• Cortical bone: dense, outer shell of the 
vertebra 
Haversian System 
Detail of Cortical 
Bone 
Detail of Cancellous 
Bone 
• Cancellous bone: inner, spongy 
bone
Vertebral Arches 
• Anterior Arch 
Composed of: 
– Vertebral body 
– Anterior 1/3 of the pedicles 
• Posterior Arch 
Comprised of: 
– Posterior 2/3 of the 
pedicles 
– Lamina 
– Processes 
Together the anterior arch and posterior arch create a large, closed 
space called the VERTEBRAL FORAMEN. When the individual 
vertebrae are stacked on each other, the vertebral foramen form the 
SPINAL CANAL, which contains and protects the spinal cord.
Vertebral 
Body 
Pedicle 
Lamina Superior 
Articular 
Process 
Spinous 
Process 
Transverse 
Process 
Vertebral 
Foramen 
Vertebral Structures
Vertebral Structures 
Superior 
Articular 
Process 
Inferior 
Articular 
Process 
Pars 
Zygapophyseal 
Joint 
(Facet Joint)
Vertebral Structures 
• Pedicle notches: The pedicles exit 
the upper one third of the vertebral 
body. They are notched slightly on 
the superior surface and deeply 
notched on the inferior surface. Slight 
Notch 
Deep 
Notch 
• Intervertebral foramen: When the 
vertebrae are stacked on one 
another the pedicle notches form 
the INTERVERTEBRAL FORAMEN 
through which the spinal nerve 
roots leave the spinal cord and 
exit to the body. 
Intervertebral 
Foramen
Transverse foramen, Intervertebral 
foramen, and Nerve roots 
Contents of Transverse foramen – vertebral artery, vertebral 
venous plexus, sympathetic chain 
Intervertebral foramen bounded by the pedicle, vertebral 
body, disc and superior articular process * 
Intervertebral Discs : thicker in the cervical and lumbar region 
and thicker anteriorly than posteriorly 
- axial loading absorb, flexibility 
- nucleus pulposus, annulus fibrosis, cartilaginous endplate 
Adamkiewicz artery : supply to the lower two-thirds of the 
spinal cord , enter the spinal canal via an intervertebral 
foramen 
-> transforaminal or periganglionic intervention damage
The Vertebral Ligaments 
Ligament – stability, flexion, extension, rotation 
- ALL, PLL, ligamentum flavum, interspinous 
ligament, supraspinous ligament 
- ALL : vertebral body and intervertebral disc 
- PLL : annulus fibrosis but does not contact the 
posterior vertebral margin 
- ligamentum flavum : laminar segment extend, 
spinal canal dorsolateral margin define 
- interspinous ligament, supraspinous lig. : spinous 
process
Intervertebral Disc 
• Intervertebral disc 
• Endplate 
– Cartilaginous layer 
– Bony layer 
• Apophyseal ring
The Intervertebral Disc 
• The disc is a shock absorber that is positioned between 
each end plate. 
• A normal disc is contains water and therefore is bright 
white in color on certain types of MRI images (T2 images). 
• nucleus pulposus : type II collagen, hyaluronic acid, 
glycoaminoglycan 
• annulus fibrosis : outer dense circumferential fibrous band 
and inner fibrocartilagenous layer 
• Injury to the disc can result in disc protrusions, tears in the 
outer fibers of the disc, reduction in disc height and pain.
YYoouurr TTuurrnn!!
Vertebral 
Body 
Pedicle 
Lamina Superior 
Articular 
Process 
Spinous 
Process 
Transverse 
Process 
Type of 
Cboannec?ellous 
Vertebral 
Foramen 
Name the 
Structures 
Type of 
Cboorntiec?al 
? 
? 
? 
? 
? 
? 
? 
Your Turn
RReeggiioonnss ooff tthhee SSppiinnee
• Cervical 
Regions of the Spine 
– Upper cervical: C1-C2 
– Lower cervical: C3-C7 
– The skull is often considered 
to be part of the spine and is 
then referred to as C0. 
• Thoracic: T1-T12 
• Lumbar: L1- L5 
• Sacrococcygeal: 9 
fused vertebrae in the 
sacrum and coccyx. 
Labeling of the 
vertebrae
Upper Cervical Vertebrae, C1-C2 
• Occipitocervical junction: 
– Occiput (C0) and Atlas (C1) 
– No disc 
• Atlantoaxial junction: 
– Atlas (C1) and Axis (C2) 
– No disc
The Atlas (C1) 
Transverse 
Process 
Transverse 
Foramen 
Anterior 
Tubercle Articular Facet 
for Dens 
Lateral 
Mass 
Posterior Lamina 
Tubercle 
Superior 
Articular 
Facet 
Superior View
The Axis (C2) 
Odontoid 
Process 
(Dens) 
Body 
Transverse 
Process 
Inferior 
Articular 
Facet 
Superior 
Articular 
Facet 
Lateral 
Mass 
Spinous 
Process 
Anterior View Posterior View
Typical cervical, thoracic, and lumbar 
vertebra 
• Anterior body, 
• paired pedicles, articular pillars and laminae, and 
• a single dorsal midline spinous process 
• Spinous process – serve as a attachment point for the posterior 
ligamentous structures 
• Pedicle, articular pillars, and lamina - serve to protect the spinal 
cord and nerve roots 
• Transverse process 
in the mid-cervical : vertebral artery, osseous transverse foramina 
in the thoracic and lumbar spine : spinal column protect stabilize 
muscle
Lower Cervical Vertebrae 
• C3 to C7 
– May be referred to as 
the subaxial region 
– Disc at every level 
– Vertebral structures 
are similar
Lower Cervical Vertebrae 
C3 - C7 
Transverse 
Sulcus for Body Process 
Spinal Nerve 
Lateral 
Mass 
Lamina 
Pedicle 
Transverse 
Foramen 
Superior 
Articular Facet 
Vertebral 
Foramen 
Bifid Spinous Process 
Axial View
Lower Cervical Vertebrae 
The vertebral bodies of the subaxial cervical spine have upward 
projections on the lateral margins called UNCINATE PROCESSES. These 
processes articulate with the level above to form the UNCOVERTEBRAL 
JOINT. These are also called JOINTS OF LUSCHKA. They are not capsular 
joints, but they do provide for some stability of the motion segments by 
their fibrous attachments. 
Uncinate 
Process 
Uncovertebral Joint 
(Joint of Luschka) 
C3 - C7 
Anterior View 
Sulcus for 
Spinal Nerve
Vertebra Prominens (C7) 
Spinous 
Process 
Axial View 
C7 is sometimes referred to as the 
VERTEBRA PROMINENS because it 
has a longer and larger spinous 
process than the other cervical 
vertebrae. This spinous process is 
not usually bifid. Because it is so 
easily palpated at the base of the 
neck posteriorly, the vertebra 
prominens is used as an anatomic 
landmark to count the spinous 
processes of the thoracic vertebrae 
lying below.
Thoracic Vertebrae 
• Body - progressive increase in mass 
from T1 to T12 
• Pedicles - small diameter 
• Laminae - vertical, with “roof tile” 
arrangement 
• Spinous processes - long, 
overlapping, projected downward 
• Intervertebral foramen - larger, 
less incidence of nerve 
compression
Thoracic Vertebrae, T1-T12 
• Body - heart shaped when viewed 
superiorly. 
• Vertebral foramen - round 
• Pedicles - small in 
diameter 
• Spinous processes - long 
and projected downwards
Thoracic Vertebrae, T1-T12 
• Articular processes 
Superior Articular 
Process 
Inferior Articular 
Process
Thoracic Vertebrae, T1-T12 
• Costal and costotransverse facets 
On both sides of the vertebral body, there are smooth, rounded 
facet joints called the COSTOVERTEBRAL JOINTS. The ribs at 
the levels of T2-T9 articulate with two vertebrae at these 
synovial joints. The transverse process also attaches to the rib 
at the costotransverse articulation. The T1, T10, T11 and T12 
vertebrae form joints with one rib only and have a single 
articulation on each side. 
Costal 
Facet 
Costotransverse 
Facet
Thoracic Vertebrae, T1-T12 
C6 • The rib cage and spinous processes 
limit motion of the thoracic spine. 
This can put a strain on the cervical 
and lumbar vertebrae closest to the 
less mobile thoracic spine and 
makes them prone to injury. 
• Junctional vertebrae 
– C6 to T2 
– T11 to L2 
– adjacent regions are more prone 
to injury 
• Floating ribs at T11 and T12
Lumbar Vertebrae, L1-L5 
• Body - L1 to L5 progressive 
increase in mass 
• Pedicles - longer and wider than 
thoracic; oval shaped 
• Spinous processes - horizontal, 
square shaped 
• Transverse processes - smaller 
than in thoracic region 
• Intervertebral foramen - large, 
but with increased incidence of 
nerve root compression
The Sacrum 
Sacral Horns (superior articular 
processes) 
Sacral Ala 
Inverted triangle shape 
Pedicles 
Dorsal 
Foramina 
Sacral 
Hiatus 
Coccyx 
Posterior View
Sacral Tilt 
30°-60° 
Sacral Canal 
Coccyx 
Sacral 
Promontory 
Lateral View 
1 
2 
3 
4 
5 
Sacral Hiatus 
The Sacrum
Iliac Crests 
The ILIAC CRESTS are important in 
spine surgery because autogenous 
bone graft is often harvested from 
them. Both cortico-cancellous and 
cancellous bone graft can be obtained 
from either iliac crest. The posterior 
iliac crests are sometimes used to 
provide additional support and fixation 
for long rod constructs. This is 
generally referred to as sacropelvic 
fixation.
YYoouurr TTuurrnn!!
Your Turn: Name the Regions 
? 
Cervical 
? 
Thoracic 
? 
? 
Lumbar 
Sacral
Your Turn: Name the Vertebrae 
Atlas 
(superior vi?ew) 
Axis ? 
(povsietewr)ior 
Lower Cervical 
(anterior view) 
?
Your Turn: Name the Vertebrae 
Lumbar 
Sacral 
Thoracic 
? 
? 
?
IInntteerrvveerrtteebbrraall DDiisscc
The Intervertebral Disc 
• The disc is a shock absorber that is positioned between 
each end plate. 
• A normal disc is contains water and therefore is bright 
white in color on certain types of MRI images (T2 images). 
• nucleus pulposus : type II collagen, hyaluronic acid, 
glycoaminoglycan 
• annulus fibrosis : outer dense circumferential fibrous band 
and inner fibrocartilagenous layer 
• Injury to the disc can result in disc protrusions, tears in the 
outer fibers of the disc, reduction in disc height and pain.
Intervertebral Disc 
• Fibrocartilaginous joint of the 
motion segment 
• Make up ¼ the length of the 
spinal column 
• Present at levels C2-C3 to L5- 
S1 
• Allows compressive, tensile, 
and rotational motion 
• Largest avascular structures 
in the body
Intervertebral Disc 
• Annulus Fibrosus 
– Outer portion of the disc 
Lamellae 
– Made up of lamellae 
– Great tensile strength 
Annulus 
Fibrosus 
• Layers of collagen 
fibers 
• Arranged obliquely 
30° 
• Reversed contiguous 
layers
Intervertebral Disc 
• Nucleus Pulposus Nucleus 
– Inner structure Pulposus 
– Gelatinous 
– High water content 
– Resists axial forces
Transverse foramen, Intervertebral 
foramen, and Nerve roots 
Contents of Transverse foramen – vertebral artery, vertebral 
venous plexus, sympathetic chain 
Intervertebral foramen bounded by the pedicle, vertebral 
body, disc and superior articular process * 
Intervertebral Discs : thicker in the cervical and lumbar region 
and thicker anteriorly than posteriorly 
- axial loading absorb, flexibility 
- nucleus pulposus, annulus fibrosis, cartilaginous endplate 
Adamkiewicz artery : supply to the lower two-thirds of the 
spinal cord , enter the spinal canal via an intervertebral 
foramen 
-> transforaminal or periganglionic intervention damage
• The spinal cord is a long thin bundle of 
nervous tissue that conducts information from 
the brain to the peripheral nervous system. 
• The spinal fluid bathes the spinal cord in fluid.
YYoouurr TTuurrnn!!
The intervertebral disc is composed of the 
________________ and the annulus fibrosus __n_u_c_le_u_s_ p_u_l_p_o_s_u_s__. 
The layers of the annulus fibrosus 
are called the __l_a_m_e_l_la_e__ . 
The intervertebral disc is the largest 
__a_v_a_s_c_u_la_r___ structure in the body.
TThhiiss ccoonncclluuddeess 
BBaassiicc VVeerrtteebbrraall SSttrruuccttuurreess 
TThhaannkk YYoouu!!
JJooiinnttss RReellaatteedd ttoo 
tthhee SSppiinnee
Joints 
• atlanto-occipital : occipital condyle ~ lateral mass of C1 
• Atlantoaxial : ventral dens ~ dorsal surface of C1 anterior arch 
• Uncovertebral : dorsolateral margin of the superior endplate of the 
C3~C7 
• Costovertebra and Costotransverse : rib ~ vertebral body or transverse 
process of the thoracic spine 
• zygoapophyseal (facet) joints : the most prevalent joints , superior and 
inferior articular process *
Occipitocervical Joint 
Occipital 
Condyles 
Foramen 
Magnum 
articulate with 
C1 superior 
facets
Atlantoaxial Joint 
The articulation of the ATLANTOAXIAL 
JOINT between the atlas (C1) and the 
axis (C2) has a range of motion in the 
transverse plane for rotation. 
The DENS of C2 acts as a 
pivot point for the rotation of 
C1. 
The articulating surfaces of the two 
vertebrae form the 
C2 
ZYGAPOPHYSEAL (FACET) JOINTS 
that allow flexion-extension, side 
bending, and rotational movements. Zygapophyseal joints 
C1 
Dens
The Facet Joints 
The facet joints are also called 
ZYGAPOPHYSEAL JOINTS. 
The facet joints are formed by the 
articular processes of adjacent vertebrae. 
The inferior articular process of a vertebra 
articulates with the superior articular 
process of the vertebra below. 
The facets are synovial gliding joints 
because the articular surfaces glide over 
each other. They are capsular joints 
containing synovial fluid for lubrication.
The Facet Joints 
Facet joints are oriented in different 
planes depending on their anatomic 
location. The orientation of the facets 
controls the type and amount of joint 
motion. 
These hinges demonstrate the 
planes and angulation of the 
facet joints at each vertebral 
level.
Cervical Facet Joints 
45° to the axial 
plane 
In the cervical region, the facet joints are flat 
and oriented 45° to the horizontal. This means that 
the cervical region has a significant range of motion 
in the six degrees of freedom.
Thoracic Facet Joints 
60° to the axial 
plane 
20° to the frontal 
plane 
In the thoracic region, the facet 
joints are flat and oriented 60° to the axial 
plane and 20° to the frontal plane with the 
inclination medially. Although the facets alone 
would allow for significant motion, the rib 
cage and spinous processes limit motion in 
extension, and rotation.
Lumbar Facet Joints 
90° to the axial plane 
45° to the frontal 
plane 
In the lumbar area, the facet joints are 
curved: the superior articular processes are 
concave, and the inferior articular processes are 
convex. They are oriented 90° to the axial plane 
and 45° to the frontal plane. Because of this 
orientation, the lumbar facets limit rotation but 
allow for flexion, extension, and side bending. 
When surgery is performed in the lumbar spine 
and the facets are destroyed, the potential for 
abnormal rotational movement increases.
Uncovertebral Joints 
Uncovertebral 
Joint 
The bony elevations on the 
superior lateral margins of the cervical 
vertebrae are called UNCINATE 
PROCESSES. 
These joints articulate with the 
inferior, lateral aspect of the vertebra 
above to form the UNCOVERTEBRAL 
JOINTS, also known as the JOINTS 
OF LUSCHKA. These are fibrous joints 
and do not have a capsule, but do 
provide stability, primarily in the M-L 
plane. 
The uncovertebral joints are not true 
joints but are often referred to as joints 
by spinal surgeons. 
Uncinate 
Process
Costovertebral Joints 
The T2-T9 thoracic vertebra 
have facets superiorly and inferiorly 
at the posterior aspect of the 
vertebral body that form the 
COSTOVERTEBRAL joints. 
Costovertebral 
joints 
Rib 
Costotransverse 
joints 
Axial View 
In the thoracic spine, the RIBS 
articulate with the vertebrae at both the body 
and the transverse processes. 
At all thoracic levels there is a 
facet where the rib articulates with 
the transverse process. These are 
called the COSTOTRANSVERSE 
joints. 
The T1 and T10-T12 vertebral 
bodies have only one costal facet. 
Rib
Lateral View 
Costovertebral 
joints 
Costotransverse 
joint 
Rib 
Costovertebral Joints
Lumbosacral Joint 
The LUMBOSACRAL JOINT is formed 
anteriorly by the wedge-shaped 
intervertebral disc 
Anterior View
Lumbosacral Joint 
and posteriorly by the L5-S1 facets. Two 
large articulating processes extend superiorly 
from S1 to meet with the inferior articulating 
processes of L5. 
L5 
Posterior View 
The S1 superior articular processes are 
sometimes referred to as the SACRAL HORNS. 
These processes create facet joints that are 
oriented almost 90° in the coronal and axial 
planes and help to offset the significant shear 
forces caused by the 30° to 60° tilt of the 
superior endplate of S1. 
The lumbosacral joint is under great loading 
force because of the highly mobile lumbar 
segment joining with the rigid sacrum. 
Degenerative disease and spondylolisthesis often 
occur at the lumbosacral junction. 
sacrum
Sacroiliac Joint 
Sacroiliac 
Ligaments 
Sacrum 
Ilium 
The superior lateral surface on 
either side of the sacrum articulates 
with the inner aspects of the pelvis. 
This area forms the capsular, synovial 
SACROILIAC JOINT. 
The sacroiliac joint is also 
encompassed in a large amount of 
ligamentous and fibrous tissue for 
added stability. Therefore, the 
sacroiliac joint is both a capsular and a 
ligamentous joint. In some cases the 
sacroiliac joint is a hidden source of 
back pain.
YYoouurr TTuurrnn!!
Your Turn: Joints 
facet 
This joint is called the _____ joint or 
the _______________ zygapophyseal joint. 
This junction is called the 
_u_n_c_o_v_e_rt_e_b_ra_l__ joint. 
Bonus: Although not a true joint, it is 
sometimes called the joint of 
________. 
Luschka 
The articulations of the ribs with the 
vertebrae are called the 
_c_o_st_o_v_e_rt_e_b_r_a_l _ joints.
Your Turn: Joints 
lumbosacral 
The ____________ joint is under a 
great loading force and has a high 
incidence of degenerative disease. 
The articulation of the sacrum with the 
pelvis is called the _s_a_c_ro_i_li_a_c__ joint.
LLiiggaammeennttss
Spinal Ligaments 
LIGAMENTS are bands or sheets of 
tough, fibrous tissue connecting two or more 
bones, cartilage bands, or other structures. 
They only become active when a joint is 
stressed to its maximum range of motion, 
protecting the joints from being hyperflexed 
or hyperextended. 
Ligaments are strongly anchored to the 
cortical bone of the vertebrae. Ligamentous 
structures are found in all regions of the 
spine. We will examine and identify the 
important ligaments in each region. Because 
of the significant ligamentous structures in 
the upper cervical region, we will examine 
that area separately.
Upper Cervical Ligaments 
The ligamentous structures of the 
upper cervical spine are extremely 
important in maintaining the stability 
of the spinal column and preventing 
neurologic injury. Ligamentous 
instability can result in significant 
subluxation of the C1-C2 complex, 
resulting in potentially catastrophic 
neurologic injury. The most important 
ligaments in the cervical area are 
discussed in this section.
Upper Cervical Ligaments 
Occipitoatlantal Ligament 
Complex 
Anterior 
occipitoatlantal 
ligament 
Posterior 
occipitoatlantal 
ligament 
Lateral 
occipitoatlantal 
ligament 
Anterior View
Upper Cervical Ligaments 
Atlantoaxial Ligament Complex 
Anterior view Posterior cutaway view 
Anterior 
atlantoaxial 
ligament 
Lateral 
atlantoaxial 
ligament 
capsule 
Posterior 
atlantoaxial 
ligament
Upper Cervical Ligaments 
Occipitoaxial Ligament Complex 
Alar ligaments (2) 
Apical 
ligament 
Posterior cutaway view 
Occipitoaxial 
ligament 
Posterior view
Upper Cervical Ligaments 
Cruciate Ligament 
Complex 
Superior 
longitudinal 
fascicle 
Inferior 
longitudinal 
fascicle 
Transverse 
ligament 
Posterior View
Upper/Lower Cervical Ligaments 
Superior 
longitudinal 
fascicle 
Anterior 
occipitoatlantal 
ligament 
Inferior 
longitudinal 
fascicle 
Posterior 
occipitoatlantal 
ligament 
Vertebral artery 
Lateral, Cross-sectional View 
Ligamentum 
nuchae 
Posterior 
atlantoaxial 
ligament 
Ligamentum 
flavum 
Transverse 
ligaments 
Anterior 
longitudinal 
ligament 
Posterior 
longitudinal 
ligament
Lower Cervical, Thoracic, 
and Lumbar Ligaments 
Anterior Longitudinal 
Ligament (ALL) 
The ANTERIOR LONGITUDINAL 
LIGAMENT (ALL) is composed of 
thick, longitudinally oriented fibers 
extending from the axis (C2) anteriorly 
to the sacrum. The ALL is broader at the 
level of each vertebral body than at the 
level of the discs where the fibers 
adhere to the annulus fibrosus. The ALL 
attaches to each vertebral body 
superiorly and inferiorly at the levels of 
the end plates.
Lower Cervical, Thoracic, 
and Lumbar Ligaments 
Intertransverse 
ligaments 
Costal 
ligaments 
The INTERTRANSVERSE 
LIGAMENTS extend from the 
inferior surface of the entire 
length of the transverse process 
to the superior surface of the 
adjacent transverse process. 
The COSTAL LIGAMENTS 
connect the heads of the ribs to 
the vertebrae.
Lower Cervical, Thoracic, 
and Lumbar Ligaments 
The POSTERIOR LONGITUDINAL 
LIGAMENT (PLL) is weaker than the ALL. 
Its fibers are also longitudinally oriented but 
less dense. It runs from the axis (C2) 
caudally to the sacrum. The PLL is narrow 
at the levels of the vertebrae, but the fibers 
extend laterally at the disc levels. These 
fibers may help to contain herniated disc 
material. Like the ALL, the PLL is attached 
to the vertebra at the superior and inferior 
margins, and to the annular fibers of the 
intervertebral disc. 
Posterior longitudinal ligament
Lower Cervical, Thoracic, and 
Interspinous 
ligament 
Lumbar Ligaments 
Ligamentum 
nuchae 
The INTERSPINOUS 
LIGAMENT connects each adjacent 
spinous process. The fibers extend 
from the base to the tip of each 
spinous process. 
In the cervical spine the 
interspinous ligament becomes part 
of the LIGAMENTUM NUCHAE, a 
fibro-membranous complex that 
extends from the interspinous 
ligament posteriorly and cranially to 
insert into the occiput.
Lower Cervical, Thoracic, and 
Lumbar Ligaments 
The SUPRASPINOUS 
LIGAMENT is a very strong band 
connecting the tips of 
contiguous spinous processes. It 
extends from C7 (vertebra 
prominens) to the sacrum. 
Supraspinous 
ligament 
Above C7 these fibers are 
Ligamentum 
nuchae 
part of the LIGAMENTUM 
NUCHAE.
Lower Cervical, Thoracic, 
and Lumbar Ligaments 
Ligamentum 
flavum 
The LIGAMENTUM FLAVUM, 
also called the YELLOW 
LIGAMENT, consists of elastic 
fibers oriented vertically that 
extend from the anterior inferior 
surface of the lamina above to the 
superior posterior surface of the 
lamina below. Unlike the ALL and 
PLL, the ligamentum flavum is not 
continuous. There is a small space 
in the midline between the right 
and the left fibers. The ligamentum 
flavum tends to thicken as it 
progresses down the spine, 
beginning at the axis (C2) and 
extending to the sacrum.
Lumbosacral Ligaments 
The ILIOLUMBAR LIGAMENTS 
extend from the transverse 
processes of L4 and L5 to the iliac 
crest. 
Iliolumbar 
ligaments 
Anterior View Posterior View
Lumbosacral Ligaments 
Lumbosacral 
ligaments 
Anterior View 
The LUMBOSACRAL 
LIGAMENT is a thick, fibrous band 
that extends from the anterior, 
inferior aspect of the transverse 
process of L5 to the lateral surface 
of the sacrum.
Sacroiliac Ligaments 
Short sacroiliac 
ligaments 
Posterior View 
The SACROILIAC LIGAMENTS are 
Long sacroiliac 
ligaments 
as follows: 
• short sacroiliac ligaments: 
composed of horizontal fibers 
extending from the sacrum to 
the posterior part of the iliac 
bone 
• long sacroiliac ligaments: 
composed of fibers extending 
vertically from the sacrum to 
the posterior superior iliac 
spine
YYoouurr TTuurrnn!!
Ligaments connect _b_o_n_e__ to _b_o_n_e__. 
Posterior 
longitudinal 
ligament 
(PLL) ? 
Anterior 
longitudinal 
ligament 
(ALL) ? 
Costal 
ligament ? 
Interspinous 
l?igament 
Ligamentum 
flavum? ?Supraspinous 
ligament 
Your Turn: Ligaments
TThhiiss ccoonncclluuddeess 
JJooiinnttss aanndd LLiiggaammeennttss 
TThhaannkk YYoouu!!
SSppiinnaall MMuusscclleess
Spinal Muscles 
Muscles related to the spine can 
be segmented into anterior and 
posterior groups. 
These groups can be further 
divided into superficial, middle, and 
deep layers. Muscles are attached to 
bone by tendons.
Anterior Spinal Muscle Groups 
Cervical 
The muscles most 
important to the anterior 
cervical spine are: 
• Longus capitis: originates 
at the occipital bone with 
insertions at the tranaverse 
processes of C3-C6 
Longus 
capitis 
Longus 
colli 
Scalene 
• Longus colli: originates 
at the anterior portion of 
the vertebral bodies from 
C1-T3 with insertions at 
inferior vertebral bodies 
• Scalene: Connects the 
transverse processes of 
the cervical spine with the 
first two ribs
Anterior Spinal Muscle Groups 
Upper and Midthoracic 
Anteriorly, there are no 
muscles significant to spinal 
anatomy at these regions
Anterior Spinal Muscle Groups 
Lower Thoracic and Lumbar 
• Quadratus lumborum:from 
transverse processes of L1-L4 to 
iliac crest 
• Psoas Iliacum: Composed of: 
– Psoas major: from 
transverse processes 
and vertebral body of 
T2-L5 to the lesser 
trochanter of the 
femur 
– Iliacus: from the 
anterior margin of the 
iliac crest and the 
lesser trochanter of 
the femur
Posterior Spinal Muscle Groups 
The posterior back musculature can be 
divided into superficial, middle, and deep 
layers. These muscle groups form the 
TENSION BAND. 
The posterior muscle groups are often 
stripped from their bony attachments to the 
spine during surgical procedures. 
Compromise of the tension band may result 
in loss of sagittal plane balance.
Posterior Spinal Muscle Groups 
The superficial posterior 
muscles are collectively called the 
ERECTOR SPINAE, comprising three 
groups: 
Iliocostalis 
Longissimus 
Spinalis 
Erector 
Spinae
Posterior Spinal Muscle Groups 
Iliocostalis 
iliocostalis cervicis 
iliocostalis thoracis 
iliocostalis lumborum 
Longissimus 
longissimus 
capitis 
Spinalis 
spinalis capitis 
longissimus cervicis 
longissimus thoracis 
spinalis cervicis 
spinalis thoracis 
Detail of the 
ERECTOR SPINAE 
groups:
Posterior Spinal Muscle Groups 
The middle, or intermediate, muscle group of the spine 
is called the SEMISPINALIS GROUP: 
semispinalis 
capitis 
(cut) 
semispinalis 
cervicis (lies 
beneath layer 
shown) 
semispinalis 
thoracis
Posterior Spinal Muscle Groups 
The deep muscle layer 
consists of the following 
groups: 
Multifidus 
C1 to Sacrum 
(rotational 
movements) 
Intertransversarii 
attachments 
between spinous 
processes 
Rotatores 
(longus and brevis) 
attachments 
between transverse 
process and 
spinous process 
Rotatores 
cervices 
Rotatores 
thoracis 
Rotatores 
lumborum 
Levatores costae 
(longus and brevis) 
attachments 
between transverse 
process and ribs, 
C1-T11, and rib to 
rib
YYoouurr TTuurrnn!!
Your Turn: Muscles 
anterior 
Muscles can be segmented into _________ and 
_p_o_s_te_r_io_r__ groups. 
superficial middle 
Muscles can be subdivided into ___________, _________, 
and _________ deep 
layers. 
tension band 
The posterior muscle groups form the _______ ______ and 
provide sagittal plane balance.
NNeerrvvee SSttrruuccttuurreess
• The spinal cord is a long thin bundle of 
nervous tissue that conducts information from 
the brain to the peripheral nervous system. 
• The spinal fluid bathes the spinal cord in fluid.
Spinal Nerve Structures 
Spinal Cord 
• Contained in epidural space 
• Network of sensory and motor 
nerves 
• Firm, cord-like structure 
Foramen 
magnum 
• Extends from foramen magnum to 
L1 
• Terminates at the 
conus medularis 
• The cauda equina begins 
below L1 
• Filum terminale extends from 
conus medularis to the coccyx 
Conus 
medularis 
Cauda 
equina
Meninges 
The brain and spinal cord are covered by 
three layers of material called MENINGES. 
The main function of these layers is to protect 
and feed the delicate neurological structures. 
Dura mater 
Subdural space 
Arachnoid 
layer 
Subarachnoid 
space: filled 
with CSF 
Pia mater
Spinal Nerve Topography 
31 pairs of spinal nerves 
• 8 cervical 
• 12 thoracic 
• 5 lumbar 
• 6 sacrococcygeal
Spinal Nerves 
Spinal 
cord 
Epidural 
space 
Dura mater and 
Arachnoid layers 
Subarachnoid 
space 
Dorsal root 
Ventral 
root 
Dorsal root 
ganglion 
Peripheral 
nerve
Autonomic Nervous System 
The AUTONOMIC NERVOUS 
SYSTEM (ANS) is a specialized system 
independent of voluntary control. The 
ANS controls glandular and cardiac 
function and smooth muscle such as 
that found in the digestive tract. All of 
the above organs are under involuntary 
control by the ANS. There are two 
components of the ANS: the 
sympathetic and the parasympathetic 
systems. The control centers of both 
systems are located outside the spinal 
cord in structures called GANGLIA.
Autonomic Nervous System 
The SYMPATHETIC NERVOUS 
SYSTEM consists of a series of ganglia 
extending from the skull to the coccyx, 
lying on each side of the vertebral bodies. 
These aligned ganglia look like a chain at 
each side of the spine and are often 
referred to as the sympathetic nerve chain. 
Injury to the sympathetic nerve chain in the 
lumbar spine may result in genitourinary 
problems for the patient. Each sympathetic 
ganglion has fibers that join to the adjacent 
spinal nerve, which creates redundancy 
within the system. 
The PARASYMPATHETIC 
NERVOUS SYSTEM (not shown) has 
ganglia located close to the organs they 
control.
YYoouurr TTuurrnn!!
Your Turn: Nerve Structures 
The spinal cord exits the skull 
through the __fo_ra_m_e_n__ _m_a_g_n_um___. 
At the ____ L1 
level, the spinal cord 
terminates as the _____ conus medularis 
_______. 
Below L1, the spinal nerves are 
collectively known as the _____ 
cauda 
_____. 
equina 
The _____ filum _______ terminale 
extends to the 
coccyx and helps anchor the lower 
spinal cord.
Your Turn: Nerve Structures 
The layers of tissue covering the spinal cord are 
called the _m_e_n_in_ge_s__. 
? ? 
Dura mater 
Subdural space 
Arachnoid 
layer 
Subarachnoid 
space: filled 
with CSF 
Pia mater 
? 
? 
? 
Name the 
Structures
Your Turn: Nerve Structures 
Spinal 
cord 
Epidural 
space 
Subarachnoid 
space 
Dorsal root 
Ventral 
root 
Dorsal root 
ganglion 
Peripheral 
nerve 
? ? 
? 
? 
? 
? 
? 
Name the 
Structures
TThhiiss ccoonncclluuddeess 
MMuusscclleess aanndd NNeerrvveess 
TThhaannkk YYoouu!!
VVaassccuullaarr SSttrruuccttuurreess 
RReellaatteedd ttoo tthhee SSppiinnee
Vascular Structures 
Blood vessels are divided into two groups: 
ARTERIES are vessels carrying 
oxygenated blood from the heart to the 
internal organs and peripheral circulation. 
VEINS are vessels carrying deoxygenated 
blood back to the heart from the internal 
organs and peripheral circulation. 
There are two exceptions to the above 
definitions: the pulmonary artery carries 
deoxygenated blood from the heart to the lungs, 
where the blood is reoxygenated. The pulmonary 
veins carry oxygenated blood back to the heart 
from the lungs for circulation throughout the 
body. Together, the arteries and veins form a 
complex vascular tree with multiple branches 
reaching the smallest and farthest areas of the 
human body.
Arteries of the Cranial and Cervical 
Region 
Circle of Willis 
Vertebral 
arteries 
Basilar 
artery 
Internal 
carotid 
arteries
Arteries of the Cranial and Cervical 
Region 
Foramen 
lacerum 
Vertebral 
artery 
Carotid 
artery 
Anterior to the cervical 
vertebrae are the CAROTID 
ARTERIES, which ascend 
through the FORAMEN 
LACERUM and join with the 
vertebral arteries to form the 
CIRCLE OF WILLIS. Because 
of their proximity to the cervical 
vertebrae, they must always be 
considered during any anterior 
cervical procedure.
Arteries of the Thoracic and 
VertebrLalu mbosacral Regions 
artery Aortic arch 
Ascending 
aorta Descending 
aorta 
Thoracic 
segmental 
arteries 
Abdominal 
aorta 
Bifurcation 
of the aorta Lumbar 
segmental 
External iliac arteries 
artery (left & 
right) Internal 
iliac artery 
Femoral artery (left & right) 
(left & right)
Segmental Arteries 
At each vertebral level from T4 to the sacrum, a pair 
of SEGMENTAL ARTERIES branches posteriorly from 
the aorta to supply blood to the vertebral body, posterior 
elements, spinal cord, and costal structures. 
Spinal 
branch 
Intercostal 
artery 
Segmental 
arteries 
Aorta 
Anterior spinal 
artery 
Posterior 
branch 
Anastomoses
Veins of the Cervical and Thoracic 
Region 
The most important venous structures in the cervical spine 
are the internal and external JUGULAR VEINS. The internal 
jugular veins follow a path similar to the carotid arteries. As in 
other parts of the body, the veins form a network of vessels that 
provide compensatory circulation and a return of blood to the 
heart, even if there is a significant obstruction. The internal 
jugular veins should always be considered during any anterior 
cervical spine procedure. 
External 
jugular 
Anterior 
jugular 
Internal 
jugular
Veins of the Cervical and 
Thoracic Region 
The SUPERIOR VENA CAVA 
provides venous drainage of the cervical 
and upper thoracic spine. The segmental 
vessels from these regions drain into the 
superior vena cava. 
Superior 
vena cava
Veins of the Thoracic and Lumbar 
Internal Region 
jugular 
Superior 
Azygos vena cava 
vein 
Thoracic 
segmental 
veins Hemiazygos 
vein 
Lumbar 
segmental 
veins 
Inferior 
vena cava 
Common iliac vein 
(left and right)
Batson’s Plexus 
The AZYGOS SYSTEM is a large 
network of veins draining nutrient-rich 
blood from the intestines and other 
abdominal organs back to the heart. At 
some levels, the segmental veins drain 
into the azygos vein located on the 
right side of the abdomen, or into the 
hemiazygos vein located on the left 
side. This system of veins presents a 
particular challenge to the spine 
surgeon. 
The azygos system also 
communicates with a valveless venous 
network known as BATSON’S 
PLEXUS. When the vena cava is 
partially or totally occluded, Batson’s 
plexus provides an alternate route for 
blood return to the heart. 
Batson’s 
plexus
YYoouurr TTuurrnn!!
Your Turn: Arteries 
Vertebral 
artery Aortic arch 
Ascending 
aorta Descending 
? ? 
aorta 
Thoracic 
segmental 
arteries 
? ? 
Name the Arteries 
Abdominal 
aorta 
? 
? 
Bifurcation 
of the aorta Lumbar 
? 
segmental 
? 
External iliac arteries 
artery 
Internal 
? 
Femoral artery iliac artery 
? 
?
Internal 
jugular 
Your Turn: Veins 
Superior 
? 
Azygos ? 
vena cava 
vein 
Thoracic 
segmental 
veins Hemiazygos 
Name the Veins 
vein 
Lumbar 
segmental 
veins 
Inferior 
vena cava 
Common iliac 
veins (left and 
right) 
? 
? ? 
? ? 
?
AAnnaattoommiiccaall SSttrruuccttuurreess 
RReellaatteedd ttoo tthhee SSppiinnee 
This section discusses some of the additional 
organs and structures related to surgery of the 
spine. Vascular structures are pointed out for 
reference purposes. These structures can be 
studied by region.
Anatomical Structures Related to the Cervical Spine 
Internal carotid 
artery 
Jugular vein 
Common 
carotid artery 
Subclavian artery 
Aorta 
Posterior View 
Hyoid bone 
Epiglottis 
Thyroid gland 
Parathyroid 
glands 
Trachea 
Left vagus 
nerve 
Left recurrent 
laryngeal nerve 
Superior 
vena cava
Anatomical Structures Related to the Thoracic Spine 
Vertebral artery 
Trachea 
Esophagus 
Aortic arch 
Heart 
(in pericardium) 
Diaphragm 
Descending 
aorta
Abdominopelvic Structures Related to the Spine 
Superior 
vena cava 
Accessory 
hemiazygos 
vein 
Hemiazygos 
vein 
Azygos vein 
Inferior vena 
cava 
Portal vein 
Diaphragm 
Stomach 
Spleen 
Liver (cross 
sectioned)
Abdominopelvic Structures Related to the Spine 
Diaphragm 
Liver 
Esophagus 
Stomach Pancreas 
Parietal peritoneum 
(anterior abdominal 
wall) 
Abdominal aorta 
Small intestine 
Urinary 
bladder 
Rectum
YYoouurr TTuurrnn!!
Your Turn: Related Structures 
Vertebral artery 
Trachea 
Esophagus 
Aortic arch 
Name the Structures 
Heart 
(in pericardium) 
Diaphragm 
Descending 
aorta 
? 
? 
? 
? 
? 
? 
?
Your Turn: Related Structures 
Superior 
vena cava 
Hemiazygos 
vein 
Azygos vein 
Inferior vena 
cava 
Portal vein 
Diaphragm 
Stomach 
Spleen 
Liver (cross 
sectioned) 
? 
? ? 
? 
? 
? 
? 
? 
? 
Name the Structures
Your Turn: Related Structures 
? 
? ? 
Diaphragm 
Liver 
Esophagus 
? ? 
Stomach Pancreas 
? ? 
Parietal peritoneum 
(anterior abdominal 
wall) 
Abdominal aorta 
Small intestine 
Name the Structures 
Urinary 
bladder 
Rectum 
? 
? 
?
This concludes the Anatomy sseeccttiioonn ooff tthhiiss 
CCoouurrssee.. 
NNeexxtt ttoo bbeeggiinn tthhee PPaatthhoollooggyy sseeccttiioonn.. 
TThhaannkk YYoouu!!

Spine anatomy (basic spine 2009)

  • 1.
    BBaassiicc IInnttrroodduuccttiioonn iinnSSppiinnee ((UUnnddeerrssttaannddiinngg SSppiinnee PPrroobblleemmss)) DDrr.. MMoohhaammeedd MMoohhii EEllddiinn ,, MB-BCH , M.Sc., MD PPrrooff.. ooff NNeeuurroossuurrggeerryy,, FFaaccuullttyy ooff MMeeddiicciinnee,, CCaaiirroo UUnniivveerrssiittyy CCoonnssuullttaanntt NNeeuurroossuurrggeeoonn Basic Spine Course 04/01/2010
  • 2.
    Introductory Spine Anatomy Course • IInnttrroodduuccttiioonn ttoo AAnnaattoommyy • BBaassiicc VVeerrtteebbrraall SSttrruuccttuurreess • JJooiinnttss aanndd LLiiggaammeennttss • MMuusscclleess aanndd NNeerrvveess • VVaassccuullaarr ssttrruuccttuurreess • AAddddiittiioonnaall oorrggaannss aanndd ssttrruuccttuurreess
  • 3.
    OUR AIM •To be familiar with spine anatomy • To be spine-minded • To understand pathological spine diseases • To correlate symptoms and signs • To facilitate surgical skills
  • 4.
    Anatomical Planes •Anatomical position • Anatomical planes • Coronal (Frontal) Plane divides the body into front and back sections • Sagittal Plane divides the body into left and right sections – Median - divides the body into equal left and right parts • Axial (Horizontal or Transverse) Plane - divides the body into upper and lower segments
  • 5.
    A-P X-ray ofa scoliotic spine in the coronal plane. The CORONAL PLANE, also called the FRONTAL PLANE, is a vertical cut that divides the body into front and back sections. Surgeons look at the coronal plane when they view an A-P (anterior-posterior) x-ray of the spine to evaluate scoliosis. Anatomical Planes
  • 6.
    Lateral X-ray ofa kyphotic spine in the sagittal plane. Anatomical Planes The SAGITTAL or MEDIAN PLANE is a vertical cut that divides the body into left and right sections. The sagittal view is seen by surgeons on a lateral x-ray of the spine.
  • 7.
    Anatomical Planes CTScan of a thoracic vertebra in the axial plane. The AXIAL or TRANSVERSE PLANE is a horizontal cut that divides the body into upper and lower sections. To best view the axial plane of the spine, surgeons will often obtain a CT scan with axial cuts.
  • 8.
    Basic Terminology •Medial - towards the midline • Lateral - away from the midline • Proximal - closer to a point of reference (extremity) • Distal - farther from a reference point (extremity) • Superior - upper part or above a specific location • Inferior - lower part or below a specific location Lateral Medial Proximal (closer to) Distal Superior to Inferior (farther from) to Additional terms used in describing anatomical positions or locations:
  • 9.
    • Cranial -the head or towards the head Cranial Caudal Anterior Posterior Dorsal Ventral • Caudal (tail) - the tail or towards the tail • Anterior - the front section or towards the front • Posterior - the back section or towards the back • Ventral - the front or anterior surface • Dorsal - the back or posterior surface Basic Terminology
  • 10.
  • 11.
    Your Turn: AnatomicalPlanes Name the Planes Axial Sagittal Corona?l ? ?
  • 12.
    Your Turn: BasicTerminology Medial Proximal Distal Closer to the midline? Above? Superior to Inferior to Below ? Closer to? Further from? Away from the Lmaidtleinrea?l Name the Positions
  • 13.
    Your Turn: BasicTerminology Caudal Name the Directions Anterior Posterior Dorsal Anterior surface? Towards the head? Towards the tail? Ventral Towards the front ? Towards the back? Posterior Surface? Cranial
  • 14.
    FFuunnccttiioonnss ooff tthheeSSppiinnee In addition to the thirty-three vertebrae, the skull and the pelvis should be considered part of the spine. This is well noted in scoliotic patients when a full length x-ray of the spine with skull and pelvis is taken to evaluate the balance of the patient. The spine is responsible for:
  • 15.
    Functions of theSpine • Protection of – spinal cord and nerve roots – internal organs
  • 16.
    Functions of theSpine • Flexibility of motion in six degrees of freedom Flexion and Extension Left and Right Rotation Left and Right Side Bending
  • 17.
    Functions of theSpine To achieve these functions, the spine must have: • Resistance to axial loading forces, accomplished by: –Kyphotic and lordotic sagittal plane curves –Increased mass of each vertebra from C1 to the sacrum •Elasticity accomplished by: –Alternating lordotic and kyphotic curves –Multiple MOTION SEGMENTS
  • 18.
    The Motion Segment • The FUNCTIONAL UNIT of the spine • Composed of: – Two adjacent vertebrae – The intervertebral disc – Connecting ligaments – Two facet joints and capsules
  • 19.
  • 20.
    Your Turn: Functionsof the Spine The spine provides protection of the spinal ________, cord _________, and ___________. nerve roots internal organs The spine is flexible in ____six degrees of freedom. The ____________ motion segment is the functional unit of the spine.
  • 21.
  • 22.
    Regions of theSpine • Line of gravity Auricle of the ear Odontoid process (C2) Body of C7 Anterior to thoracic spine Posterior to L3 Femoral head
  • 23.
    Regions of theSpine • Axial position of the spine by region Cervical - slightly anterior to the line of gravity Thoracic - significantly posterior Lumbar - middle of the body Sacrum - projects posteriorly
  • 24.
    Sagittal Plane Curves In the coronal plane, the spine is straight. A lateral curve of the spine in the coronal plane is termed SCOLIOSIS. When viewed in the sagittal plane, the normal adult spine has four curves. There are two KYPHOTIC curves and two LORDOTIC curves. KYPHOSIS: A curvature in the sagittal plane with anterior concavity (concavity towards the front). The spine has a thoracic kyphosis and sacral kyphosis. LORDOSIS: A curvature in the sagittal plane with posterior concavity (concavity towards the back). The spine has a cervical lordosis and a lumbar lordosis.
  • 25.
    Sagittal Plane Curves Cervical Lordosis 20°- 40° Thoracic Kyphosis 20°- 40° Lumbar Lordosis 30°- 50° Sacral Kyphosis
  • 26.
    Sagittal Plane Curves • Primary Curves In a fetus, the spine has a continuous curvature of kyphosis like the letter “C.” This involves all spinal regions, but only the thoracic and sacral areas remain kyphotic throughout life. These kyphotic curves are considered to be PRIMARY CURVES.
  • 27.
    Sagittal Plane Curves • Secondary Curves Lordotic curves are the spine’s response to weight bearing. When a child is two to three months of age and has sufficiently developed the posterior neck muscles, he becomes able to raise his head and keep it balanced over his shoulders. Correspondingly, the spine develops a lordotic curve in the cervical region.
  • 28.
    Sagittal Plane Curves • Secondary Curves At about one year of age, as the child begins walking, he develops a lordosis in the lumbar spine. Cervical and lumbar lordoses are considered to be SECONDARY CURVES because they develop in response to weight bearing. The purpose of these secondary curves is to keep the spine balanced in the sagittal plane and reduce the workload of the posterior spinal musculature.
  • 29.
  • 30.
    Your Turn: Regionsof the Spine cervical lumbar The _______ and _______ regions of the spine have lordotic curves. thoracic sacral The _________ and ______ regions of the spine have kyphotic curves. A fetus has a C-shaped or kyphotic _p_rim__ar_y_ curve. Secondary curves develop in the __c_er_v_ic_a_l and __lu_m_b_a_r_ regions.
  • 31.
    TThhiiss ccoonncclluuddeess IInnttrroodduuccttiioonnttoo AAnnaattoommyy.. TThhaannkk YYoouu!!
  • 32.
  • 33.
    The Spine isa building • The vertebral bodies (Osseous spinal column) are the building blocks of the spine. • There are 7 cervical, 12 thoracic, 5 lumbar vertebral bodies and 5 fused sacral segments C1 (atlas) : anterior arch, posterior arch, and paired lateral masses * C2 (axis) : bony projection which articulate with C1 (odontoid process or dens) C3 ~ C7 : dorsolateral margin of the superior endplate (uncinate process)
  • 34.
    Typical cervical, thoracic,and lumbar vertebra • Anterior body, • paired pedicles, articular pillars and laminae, and • a single dorsal midline spinous process • Spinous process – serve as a attachment point for the posterior ligamentous structures • Pedicle, articular pillars, and lamina - serve to protect the spinal cord and nerve roots • Transverse process in the mid-cervical : vertebral artery, osseous transverse foramina in the thoracic and lumbar spine : spinal column protect stabilize muscle
  • 36.
    BBaassiicc VVeerrtteebbrraall SSttrruuccttuurreess Cervical Thoraci c Lumbar All vertebrae are formed according to the same basic structures, and the same nomenclature can be applied to all regions of the spine. Only the first and second cervical vertebrae are distinct in structure. This section reviews the basic structures common to all vertebrae. Previously we identified the four regions of the spine. Now we will examine the bony structures common to each region.
  • 37.
    Types of BoneTissue There are two types of bone tissue: • Cortical bone: dense, outer shell of the vertebra Haversian System Detail of Cortical Bone Detail of Cancellous Bone • Cancellous bone: inner, spongy bone
  • 38.
    Vertebral Arches •Anterior Arch Composed of: – Vertebral body – Anterior 1/3 of the pedicles • Posterior Arch Comprised of: – Posterior 2/3 of the pedicles – Lamina – Processes Together the anterior arch and posterior arch create a large, closed space called the VERTEBRAL FORAMEN. When the individual vertebrae are stacked on each other, the vertebral foramen form the SPINAL CANAL, which contains and protects the spinal cord.
  • 39.
    Vertebral Body Pedicle Lamina Superior Articular Process Spinous Process Transverse Process Vertebral Foramen Vertebral Structures
  • 40.
    Vertebral Structures Superior Articular Process Inferior Articular Process Pars Zygapophyseal Joint (Facet Joint)
  • 41.
    Vertebral Structures •Pedicle notches: The pedicles exit the upper one third of the vertebral body. They are notched slightly on the superior surface and deeply notched on the inferior surface. Slight Notch Deep Notch • Intervertebral foramen: When the vertebrae are stacked on one another the pedicle notches form the INTERVERTEBRAL FORAMEN through which the spinal nerve roots leave the spinal cord and exit to the body. Intervertebral Foramen
  • 42.
    Transverse foramen, Intervertebral foramen, and Nerve roots Contents of Transverse foramen – vertebral artery, vertebral venous plexus, sympathetic chain Intervertebral foramen bounded by the pedicle, vertebral body, disc and superior articular process * Intervertebral Discs : thicker in the cervical and lumbar region and thicker anteriorly than posteriorly - axial loading absorb, flexibility - nucleus pulposus, annulus fibrosis, cartilaginous endplate Adamkiewicz artery : supply to the lower two-thirds of the spinal cord , enter the spinal canal via an intervertebral foramen -> transforaminal or periganglionic intervention damage
  • 44.
    The Vertebral Ligaments Ligament – stability, flexion, extension, rotation - ALL, PLL, ligamentum flavum, interspinous ligament, supraspinous ligament - ALL : vertebral body and intervertebral disc - PLL : annulus fibrosis but does not contact the posterior vertebral margin - ligamentum flavum : laminar segment extend, spinal canal dorsolateral margin define - interspinous ligament, supraspinous lig. : spinous process
  • 46.
    Intervertebral Disc •Intervertebral disc • Endplate – Cartilaginous layer – Bony layer • Apophyseal ring
  • 47.
    The Intervertebral Disc • The disc is a shock absorber that is positioned between each end plate. • A normal disc is contains water and therefore is bright white in color on certain types of MRI images (T2 images). • nucleus pulposus : type II collagen, hyaluronic acid, glycoaminoglycan • annulus fibrosis : outer dense circumferential fibrous band and inner fibrocartilagenous layer • Injury to the disc can result in disc protrusions, tears in the outer fibers of the disc, reduction in disc height and pain.
  • 48.
  • 49.
    Vertebral Body Pedicle Lamina Superior Articular Process Spinous Process Transverse Process Type of Cboannec?ellous Vertebral Foramen Name the Structures Type of Cboorntiec?al ? ? ? ? ? ? ? Your Turn
  • 50.
  • 51.
    • Cervical Regionsof the Spine – Upper cervical: C1-C2 – Lower cervical: C3-C7 – The skull is often considered to be part of the spine and is then referred to as C0. • Thoracic: T1-T12 • Lumbar: L1- L5 • Sacrococcygeal: 9 fused vertebrae in the sacrum and coccyx. Labeling of the vertebrae
  • 52.
    Upper Cervical Vertebrae,C1-C2 • Occipitocervical junction: – Occiput (C0) and Atlas (C1) – No disc • Atlantoaxial junction: – Atlas (C1) and Axis (C2) – No disc
  • 53.
    The Atlas (C1) Transverse Process Transverse Foramen Anterior Tubercle Articular Facet for Dens Lateral Mass Posterior Lamina Tubercle Superior Articular Facet Superior View
  • 54.
    The Axis (C2) Odontoid Process (Dens) Body Transverse Process Inferior Articular Facet Superior Articular Facet Lateral Mass Spinous Process Anterior View Posterior View
  • 56.
    Typical cervical, thoracic,and lumbar vertebra • Anterior body, • paired pedicles, articular pillars and laminae, and • a single dorsal midline spinous process • Spinous process – serve as a attachment point for the posterior ligamentous structures • Pedicle, articular pillars, and lamina - serve to protect the spinal cord and nerve roots • Transverse process in the mid-cervical : vertebral artery, osseous transverse foramina in the thoracic and lumbar spine : spinal column protect stabilize muscle
  • 58.
    Lower Cervical Vertebrae • C3 to C7 – May be referred to as the subaxial region – Disc at every level – Vertebral structures are similar
  • 59.
    Lower Cervical Vertebrae C3 - C7 Transverse Sulcus for Body Process Spinal Nerve Lateral Mass Lamina Pedicle Transverse Foramen Superior Articular Facet Vertebral Foramen Bifid Spinous Process Axial View
  • 60.
    Lower Cervical Vertebrae The vertebral bodies of the subaxial cervical spine have upward projections on the lateral margins called UNCINATE PROCESSES. These processes articulate with the level above to form the UNCOVERTEBRAL JOINT. These are also called JOINTS OF LUSCHKA. They are not capsular joints, but they do provide for some stability of the motion segments by their fibrous attachments. Uncinate Process Uncovertebral Joint (Joint of Luschka) C3 - C7 Anterior View Sulcus for Spinal Nerve
  • 61.
    Vertebra Prominens (C7) Spinous Process Axial View C7 is sometimes referred to as the VERTEBRA PROMINENS because it has a longer and larger spinous process than the other cervical vertebrae. This spinous process is not usually bifid. Because it is so easily palpated at the base of the neck posteriorly, the vertebra prominens is used as an anatomic landmark to count the spinous processes of the thoracic vertebrae lying below.
  • 62.
    Thoracic Vertebrae •Body - progressive increase in mass from T1 to T12 • Pedicles - small diameter • Laminae - vertical, with “roof tile” arrangement • Spinous processes - long, overlapping, projected downward • Intervertebral foramen - larger, less incidence of nerve compression
  • 63.
    Thoracic Vertebrae, T1-T12 • Body - heart shaped when viewed superiorly. • Vertebral foramen - round • Pedicles - small in diameter • Spinous processes - long and projected downwards
  • 64.
    Thoracic Vertebrae, T1-T12 • Articular processes Superior Articular Process Inferior Articular Process
  • 65.
    Thoracic Vertebrae, T1-T12 • Costal and costotransverse facets On both sides of the vertebral body, there are smooth, rounded facet joints called the COSTOVERTEBRAL JOINTS. The ribs at the levels of T2-T9 articulate with two vertebrae at these synovial joints. The transverse process also attaches to the rib at the costotransverse articulation. The T1, T10, T11 and T12 vertebrae form joints with one rib only and have a single articulation on each side. Costal Facet Costotransverse Facet
  • 66.
    Thoracic Vertebrae, T1-T12 C6 • The rib cage and spinous processes limit motion of the thoracic spine. This can put a strain on the cervical and lumbar vertebrae closest to the less mobile thoracic spine and makes them prone to injury. • Junctional vertebrae – C6 to T2 – T11 to L2 – adjacent regions are more prone to injury • Floating ribs at T11 and T12
  • 67.
    Lumbar Vertebrae, L1-L5 • Body - L1 to L5 progressive increase in mass • Pedicles - longer and wider than thoracic; oval shaped • Spinous processes - horizontal, square shaped • Transverse processes - smaller than in thoracic region • Intervertebral foramen - large, but with increased incidence of nerve root compression
  • 68.
    The Sacrum SacralHorns (superior articular processes) Sacral Ala Inverted triangle shape Pedicles Dorsal Foramina Sacral Hiatus Coccyx Posterior View
  • 69.
    Sacral Tilt 30°-60° Sacral Canal Coccyx Sacral Promontory Lateral View 1 2 3 4 5 Sacral Hiatus The Sacrum
  • 70.
    Iliac Crests TheILIAC CRESTS are important in spine surgery because autogenous bone graft is often harvested from them. Both cortico-cancellous and cancellous bone graft can be obtained from either iliac crest. The posterior iliac crests are sometimes used to provide additional support and fixation for long rod constructs. This is generally referred to as sacropelvic fixation.
  • 71.
  • 72.
    Your Turn: Namethe Regions ? Cervical ? Thoracic ? ? Lumbar Sacral
  • 73.
    Your Turn: Namethe Vertebrae Atlas (superior vi?ew) Axis ? (povsietewr)ior Lower Cervical (anterior view) ?
  • 74.
    Your Turn: Namethe Vertebrae Lumbar Sacral Thoracic ? ? ?
  • 75.
  • 76.
    The Intervertebral Disc • The disc is a shock absorber that is positioned between each end plate. • A normal disc is contains water and therefore is bright white in color on certain types of MRI images (T2 images). • nucleus pulposus : type II collagen, hyaluronic acid, glycoaminoglycan • annulus fibrosis : outer dense circumferential fibrous band and inner fibrocartilagenous layer • Injury to the disc can result in disc protrusions, tears in the outer fibers of the disc, reduction in disc height and pain.
  • 77.
    Intervertebral Disc •Fibrocartilaginous joint of the motion segment • Make up ¼ the length of the spinal column • Present at levels C2-C3 to L5- S1 • Allows compressive, tensile, and rotational motion • Largest avascular structures in the body
  • 78.
    Intervertebral Disc •Annulus Fibrosus – Outer portion of the disc Lamellae – Made up of lamellae – Great tensile strength Annulus Fibrosus • Layers of collagen fibers • Arranged obliquely 30° • Reversed contiguous layers
  • 79.
    Intervertebral Disc •Nucleus Pulposus Nucleus – Inner structure Pulposus – Gelatinous – High water content – Resists axial forces
  • 80.
    Transverse foramen, Intervertebral foramen, and Nerve roots Contents of Transverse foramen – vertebral artery, vertebral venous plexus, sympathetic chain Intervertebral foramen bounded by the pedicle, vertebral body, disc and superior articular process * Intervertebral Discs : thicker in the cervical and lumbar region and thicker anteriorly than posteriorly - axial loading absorb, flexibility - nucleus pulposus, annulus fibrosis, cartilaginous endplate Adamkiewicz artery : supply to the lower two-thirds of the spinal cord , enter the spinal canal via an intervertebral foramen -> transforaminal or periganglionic intervention damage
  • 82.
    • The spinalcord is a long thin bundle of nervous tissue that conducts information from the brain to the peripheral nervous system. • The spinal fluid bathes the spinal cord in fluid.
  • 83.
  • 84.
    The intervertebral discis composed of the ________________ and the annulus fibrosus __n_u_c_le_u_s_ p_u_l_p_o_s_u_s__. The layers of the annulus fibrosus are called the __l_a_m_e_l_la_e__ . The intervertebral disc is the largest __a_v_a_s_c_u_la_r___ structure in the body.
  • 85.
    TThhiiss ccoonncclluuddeess BBaassiiccVVeerrtteebbrraall SSttrruuccttuurreess TThhaannkk YYoouu!!
  • 86.
  • 87.
    Joints • atlanto-occipital: occipital condyle ~ lateral mass of C1 • Atlantoaxial : ventral dens ~ dorsal surface of C1 anterior arch • Uncovertebral : dorsolateral margin of the superior endplate of the C3~C7 • Costovertebra and Costotransverse : rib ~ vertebral body or transverse process of the thoracic spine • zygoapophyseal (facet) joints : the most prevalent joints , superior and inferior articular process *
  • 88.
    Occipitocervical Joint Occipital Condyles Foramen Magnum articulate with C1 superior facets
  • 89.
    Atlantoaxial Joint Thearticulation of the ATLANTOAXIAL JOINT between the atlas (C1) and the axis (C2) has a range of motion in the transverse plane for rotation. The DENS of C2 acts as a pivot point for the rotation of C1. The articulating surfaces of the two vertebrae form the C2 ZYGAPOPHYSEAL (FACET) JOINTS that allow flexion-extension, side bending, and rotational movements. Zygapophyseal joints C1 Dens
  • 90.
    The Facet Joints The facet joints are also called ZYGAPOPHYSEAL JOINTS. The facet joints are formed by the articular processes of adjacent vertebrae. The inferior articular process of a vertebra articulates with the superior articular process of the vertebra below. The facets are synovial gliding joints because the articular surfaces glide over each other. They are capsular joints containing synovial fluid for lubrication.
  • 91.
    The Facet Joints Facet joints are oriented in different planes depending on their anatomic location. The orientation of the facets controls the type and amount of joint motion. These hinges demonstrate the planes and angulation of the facet joints at each vertebral level.
  • 92.
    Cervical Facet Joints 45° to the axial plane In the cervical region, the facet joints are flat and oriented 45° to the horizontal. This means that the cervical region has a significant range of motion in the six degrees of freedom.
  • 93.
    Thoracic Facet Joints 60° to the axial plane 20° to the frontal plane In the thoracic region, the facet joints are flat and oriented 60° to the axial plane and 20° to the frontal plane with the inclination medially. Although the facets alone would allow for significant motion, the rib cage and spinous processes limit motion in extension, and rotation.
  • 94.
    Lumbar Facet Joints 90° to the axial plane 45° to the frontal plane In the lumbar area, the facet joints are curved: the superior articular processes are concave, and the inferior articular processes are convex. They are oriented 90° to the axial plane and 45° to the frontal plane. Because of this orientation, the lumbar facets limit rotation but allow for flexion, extension, and side bending. When surgery is performed in the lumbar spine and the facets are destroyed, the potential for abnormal rotational movement increases.
  • 95.
    Uncovertebral Joints Uncovertebral Joint The bony elevations on the superior lateral margins of the cervical vertebrae are called UNCINATE PROCESSES. These joints articulate with the inferior, lateral aspect of the vertebra above to form the UNCOVERTEBRAL JOINTS, also known as the JOINTS OF LUSCHKA. These are fibrous joints and do not have a capsule, but do provide stability, primarily in the M-L plane. The uncovertebral joints are not true joints but are often referred to as joints by spinal surgeons. Uncinate Process
  • 96.
    Costovertebral Joints TheT2-T9 thoracic vertebra have facets superiorly and inferiorly at the posterior aspect of the vertebral body that form the COSTOVERTEBRAL joints. Costovertebral joints Rib Costotransverse joints Axial View In the thoracic spine, the RIBS articulate with the vertebrae at both the body and the transverse processes. At all thoracic levels there is a facet where the rib articulates with the transverse process. These are called the COSTOTRANSVERSE joints. The T1 and T10-T12 vertebral bodies have only one costal facet. Rib
  • 97.
    Lateral View Costovertebral joints Costotransverse joint Rib Costovertebral Joints
  • 98.
    Lumbosacral Joint TheLUMBOSACRAL JOINT is formed anteriorly by the wedge-shaped intervertebral disc Anterior View
  • 99.
    Lumbosacral Joint andposteriorly by the L5-S1 facets. Two large articulating processes extend superiorly from S1 to meet with the inferior articulating processes of L5. L5 Posterior View The S1 superior articular processes are sometimes referred to as the SACRAL HORNS. These processes create facet joints that are oriented almost 90° in the coronal and axial planes and help to offset the significant shear forces caused by the 30° to 60° tilt of the superior endplate of S1. The lumbosacral joint is under great loading force because of the highly mobile lumbar segment joining with the rigid sacrum. Degenerative disease and spondylolisthesis often occur at the lumbosacral junction. sacrum
  • 100.
    Sacroiliac Joint Sacroiliac Ligaments Sacrum Ilium The superior lateral surface on either side of the sacrum articulates with the inner aspects of the pelvis. This area forms the capsular, synovial SACROILIAC JOINT. The sacroiliac joint is also encompassed in a large amount of ligamentous and fibrous tissue for added stability. Therefore, the sacroiliac joint is both a capsular and a ligamentous joint. In some cases the sacroiliac joint is a hidden source of back pain.
  • 101.
  • 102.
    Your Turn: Joints facet This joint is called the _____ joint or the _______________ zygapophyseal joint. This junction is called the _u_n_c_o_v_e_rt_e_b_ra_l__ joint. Bonus: Although not a true joint, it is sometimes called the joint of ________. Luschka The articulations of the ribs with the vertebrae are called the _c_o_st_o_v_e_rt_e_b_r_a_l _ joints.
  • 103.
    Your Turn: Joints lumbosacral The ____________ joint is under a great loading force and has a high incidence of degenerative disease. The articulation of the sacrum with the pelvis is called the _s_a_c_ro_i_li_a_c__ joint.
  • 104.
  • 105.
    Spinal Ligaments LIGAMENTSare bands or sheets of tough, fibrous tissue connecting two or more bones, cartilage bands, or other structures. They only become active when a joint is stressed to its maximum range of motion, protecting the joints from being hyperflexed or hyperextended. Ligaments are strongly anchored to the cortical bone of the vertebrae. Ligamentous structures are found in all regions of the spine. We will examine and identify the important ligaments in each region. Because of the significant ligamentous structures in the upper cervical region, we will examine that area separately.
  • 106.
    Upper Cervical Ligaments The ligamentous structures of the upper cervical spine are extremely important in maintaining the stability of the spinal column and preventing neurologic injury. Ligamentous instability can result in significant subluxation of the C1-C2 complex, resulting in potentially catastrophic neurologic injury. The most important ligaments in the cervical area are discussed in this section.
  • 107.
    Upper Cervical Ligaments Occipitoatlantal Ligament Complex Anterior occipitoatlantal ligament Posterior occipitoatlantal ligament Lateral occipitoatlantal ligament Anterior View
  • 108.
    Upper Cervical Ligaments Atlantoaxial Ligament Complex Anterior view Posterior cutaway view Anterior atlantoaxial ligament Lateral atlantoaxial ligament capsule Posterior atlantoaxial ligament
  • 109.
    Upper Cervical Ligaments Occipitoaxial Ligament Complex Alar ligaments (2) Apical ligament Posterior cutaway view Occipitoaxial ligament Posterior view
  • 110.
    Upper Cervical Ligaments Cruciate Ligament Complex Superior longitudinal fascicle Inferior longitudinal fascicle Transverse ligament Posterior View
  • 111.
    Upper/Lower Cervical Ligaments Superior longitudinal fascicle Anterior occipitoatlantal ligament Inferior longitudinal fascicle Posterior occipitoatlantal ligament Vertebral artery Lateral, Cross-sectional View Ligamentum nuchae Posterior atlantoaxial ligament Ligamentum flavum Transverse ligaments Anterior longitudinal ligament Posterior longitudinal ligament
  • 112.
    Lower Cervical, Thoracic, and Lumbar Ligaments Anterior Longitudinal Ligament (ALL) The ANTERIOR LONGITUDINAL LIGAMENT (ALL) is composed of thick, longitudinally oriented fibers extending from the axis (C2) anteriorly to the sacrum. The ALL is broader at the level of each vertebral body than at the level of the discs where the fibers adhere to the annulus fibrosus. The ALL attaches to each vertebral body superiorly and inferiorly at the levels of the end plates.
  • 113.
    Lower Cervical, Thoracic, and Lumbar Ligaments Intertransverse ligaments Costal ligaments The INTERTRANSVERSE LIGAMENTS extend from the inferior surface of the entire length of the transverse process to the superior surface of the adjacent transverse process. The COSTAL LIGAMENTS connect the heads of the ribs to the vertebrae.
  • 114.
    Lower Cervical, Thoracic, and Lumbar Ligaments The POSTERIOR LONGITUDINAL LIGAMENT (PLL) is weaker than the ALL. Its fibers are also longitudinally oriented but less dense. It runs from the axis (C2) caudally to the sacrum. The PLL is narrow at the levels of the vertebrae, but the fibers extend laterally at the disc levels. These fibers may help to contain herniated disc material. Like the ALL, the PLL is attached to the vertebra at the superior and inferior margins, and to the annular fibers of the intervertebral disc. Posterior longitudinal ligament
  • 115.
    Lower Cervical, Thoracic,and Interspinous ligament Lumbar Ligaments Ligamentum nuchae The INTERSPINOUS LIGAMENT connects each adjacent spinous process. The fibers extend from the base to the tip of each spinous process. In the cervical spine the interspinous ligament becomes part of the LIGAMENTUM NUCHAE, a fibro-membranous complex that extends from the interspinous ligament posteriorly and cranially to insert into the occiput.
  • 116.
    Lower Cervical, Thoracic,and Lumbar Ligaments The SUPRASPINOUS LIGAMENT is a very strong band connecting the tips of contiguous spinous processes. It extends from C7 (vertebra prominens) to the sacrum. Supraspinous ligament Above C7 these fibers are Ligamentum nuchae part of the LIGAMENTUM NUCHAE.
  • 117.
    Lower Cervical, Thoracic, and Lumbar Ligaments Ligamentum flavum The LIGAMENTUM FLAVUM, also called the YELLOW LIGAMENT, consists of elastic fibers oriented vertically that extend from the anterior inferior surface of the lamina above to the superior posterior surface of the lamina below. Unlike the ALL and PLL, the ligamentum flavum is not continuous. There is a small space in the midline between the right and the left fibers. The ligamentum flavum tends to thicken as it progresses down the spine, beginning at the axis (C2) and extending to the sacrum.
  • 118.
    Lumbosacral Ligaments TheILIOLUMBAR LIGAMENTS extend from the transverse processes of L4 and L5 to the iliac crest. Iliolumbar ligaments Anterior View Posterior View
  • 119.
    Lumbosacral Ligaments Lumbosacral ligaments Anterior View The LUMBOSACRAL LIGAMENT is a thick, fibrous band that extends from the anterior, inferior aspect of the transverse process of L5 to the lateral surface of the sacrum.
  • 120.
    Sacroiliac Ligaments Shortsacroiliac ligaments Posterior View The SACROILIAC LIGAMENTS are Long sacroiliac ligaments as follows: • short sacroiliac ligaments: composed of horizontal fibers extending from the sacrum to the posterior part of the iliac bone • long sacroiliac ligaments: composed of fibers extending vertically from the sacrum to the posterior superior iliac spine
  • 121.
  • 122.
    Ligaments connect _b_o_n_e__to _b_o_n_e__. Posterior longitudinal ligament (PLL) ? Anterior longitudinal ligament (ALL) ? Costal ligament ? Interspinous l?igament Ligamentum flavum? ?Supraspinous ligament Your Turn: Ligaments
  • 123.
    TThhiiss ccoonncclluuddeess JJooiinnttssaanndd LLiiggaammeennttss TThhaannkk YYoouu!!
  • 124.
  • 125.
    Spinal Muscles Musclesrelated to the spine can be segmented into anterior and posterior groups. These groups can be further divided into superficial, middle, and deep layers. Muscles are attached to bone by tendons.
  • 126.
    Anterior Spinal MuscleGroups Cervical The muscles most important to the anterior cervical spine are: • Longus capitis: originates at the occipital bone with insertions at the tranaverse processes of C3-C6 Longus capitis Longus colli Scalene • Longus colli: originates at the anterior portion of the vertebral bodies from C1-T3 with insertions at inferior vertebral bodies • Scalene: Connects the transverse processes of the cervical spine with the first two ribs
  • 127.
    Anterior Spinal MuscleGroups Upper and Midthoracic Anteriorly, there are no muscles significant to spinal anatomy at these regions
  • 128.
    Anterior Spinal MuscleGroups Lower Thoracic and Lumbar • Quadratus lumborum:from transverse processes of L1-L4 to iliac crest • Psoas Iliacum: Composed of: – Psoas major: from transverse processes and vertebral body of T2-L5 to the lesser trochanter of the femur – Iliacus: from the anterior margin of the iliac crest and the lesser trochanter of the femur
  • 129.
    Posterior Spinal MuscleGroups The posterior back musculature can be divided into superficial, middle, and deep layers. These muscle groups form the TENSION BAND. The posterior muscle groups are often stripped from their bony attachments to the spine during surgical procedures. Compromise of the tension band may result in loss of sagittal plane balance.
  • 130.
    Posterior Spinal MuscleGroups The superficial posterior muscles are collectively called the ERECTOR SPINAE, comprising three groups: Iliocostalis Longissimus Spinalis Erector Spinae
  • 131.
    Posterior Spinal MuscleGroups Iliocostalis iliocostalis cervicis iliocostalis thoracis iliocostalis lumborum Longissimus longissimus capitis Spinalis spinalis capitis longissimus cervicis longissimus thoracis spinalis cervicis spinalis thoracis Detail of the ERECTOR SPINAE groups:
  • 132.
    Posterior Spinal MuscleGroups The middle, or intermediate, muscle group of the spine is called the SEMISPINALIS GROUP: semispinalis capitis (cut) semispinalis cervicis (lies beneath layer shown) semispinalis thoracis
  • 133.
    Posterior Spinal MuscleGroups The deep muscle layer consists of the following groups: Multifidus C1 to Sacrum (rotational movements) Intertransversarii attachments between spinous processes Rotatores (longus and brevis) attachments between transverse process and spinous process Rotatores cervices Rotatores thoracis Rotatores lumborum Levatores costae (longus and brevis) attachments between transverse process and ribs, C1-T11, and rib to rib
  • 134.
  • 135.
    Your Turn: Muscles anterior Muscles can be segmented into _________ and _p_o_s_te_r_io_r__ groups. superficial middle Muscles can be subdivided into ___________, _________, and _________ deep layers. tension band The posterior muscle groups form the _______ ______ and provide sagittal plane balance.
  • 136.
  • 137.
    • The spinalcord is a long thin bundle of nervous tissue that conducts information from the brain to the peripheral nervous system. • The spinal fluid bathes the spinal cord in fluid.
  • 138.
    Spinal Nerve Structures Spinal Cord • Contained in epidural space • Network of sensory and motor nerves • Firm, cord-like structure Foramen magnum • Extends from foramen magnum to L1 • Terminates at the conus medularis • The cauda equina begins below L1 • Filum terminale extends from conus medularis to the coccyx Conus medularis Cauda equina
  • 139.
    Meninges The brainand spinal cord are covered by three layers of material called MENINGES. The main function of these layers is to protect and feed the delicate neurological structures. Dura mater Subdural space Arachnoid layer Subarachnoid space: filled with CSF Pia mater
  • 140.
    Spinal Nerve Topography 31 pairs of spinal nerves • 8 cervical • 12 thoracic • 5 lumbar • 6 sacrococcygeal
  • 141.
    Spinal Nerves Spinal cord Epidural space Dura mater and Arachnoid layers Subarachnoid space Dorsal root Ventral root Dorsal root ganglion Peripheral nerve
  • 142.
    Autonomic Nervous System The AUTONOMIC NERVOUS SYSTEM (ANS) is a specialized system independent of voluntary control. The ANS controls glandular and cardiac function and smooth muscle such as that found in the digestive tract. All of the above organs are under involuntary control by the ANS. There are two components of the ANS: the sympathetic and the parasympathetic systems. The control centers of both systems are located outside the spinal cord in structures called GANGLIA.
  • 143.
    Autonomic Nervous System The SYMPATHETIC NERVOUS SYSTEM consists of a series of ganglia extending from the skull to the coccyx, lying on each side of the vertebral bodies. These aligned ganglia look like a chain at each side of the spine and are often referred to as the sympathetic nerve chain. Injury to the sympathetic nerve chain in the lumbar spine may result in genitourinary problems for the patient. Each sympathetic ganglion has fibers that join to the adjacent spinal nerve, which creates redundancy within the system. The PARASYMPATHETIC NERVOUS SYSTEM (not shown) has ganglia located close to the organs they control.
  • 144.
  • 145.
    Your Turn: NerveStructures The spinal cord exits the skull through the __fo_ra_m_e_n__ _m_a_g_n_um___. At the ____ L1 level, the spinal cord terminates as the _____ conus medularis _______. Below L1, the spinal nerves are collectively known as the _____ cauda _____. equina The _____ filum _______ terminale extends to the coccyx and helps anchor the lower spinal cord.
  • 146.
    Your Turn: NerveStructures The layers of tissue covering the spinal cord are called the _m_e_n_in_ge_s__. ? ? Dura mater Subdural space Arachnoid layer Subarachnoid space: filled with CSF Pia mater ? ? ? Name the Structures
  • 147.
    Your Turn: NerveStructures Spinal cord Epidural space Subarachnoid space Dorsal root Ventral root Dorsal root ganglion Peripheral nerve ? ? ? ? ? ? ? Name the Structures
  • 148.
    TThhiiss ccoonncclluuddeess MMuusscclleessaanndd NNeerrvveess TThhaannkk YYoouu!!
  • 149.
  • 150.
    Vascular Structures Bloodvessels are divided into two groups: ARTERIES are vessels carrying oxygenated blood from the heart to the internal organs and peripheral circulation. VEINS are vessels carrying deoxygenated blood back to the heart from the internal organs and peripheral circulation. There are two exceptions to the above definitions: the pulmonary artery carries deoxygenated blood from the heart to the lungs, where the blood is reoxygenated. The pulmonary veins carry oxygenated blood back to the heart from the lungs for circulation throughout the body. Together, the arteries and veins form a complex vascular tree with multiple branches reaching the smallest and farthest areas of the human body.
  • 151.
    Arteries of theCranial and Cervical Region Circle of Willis Vertebral arteries Basilar artery Internal carotid arteries
  • 152.
    Arteries of theCranial and Cervical Region Foramen lacerum Vertebral artery Carotid artery Anterior to the cervical vertebrae are the CAROTID ARTERIES, which ascend through the FORAMEN LACERUM and join with the vertebral arteries to form the CIRCLE OF WILLIS. Because of their proximity to the cervical vertebrae, they must always be considered during any anterior cervical procedure.
  • 153.
    Arteries of theThoracic and VertebrLalu mbosacral Regions artery Aortic arch Ascending aorta Descending aorta Thoracic segmental arteries Abdominal aorta Bifurcation of the aorta Lumbar segmental External iliac arteries artery (left & right) Internal iliac artery Femoral artery (left & right) (left & right)
  • 154.
    Segmental Arteries Ateach vertebral level from T4 to the sacrum, a pair of SEGMENTAL ARTERIES branches posteriorly from the aorta to supply blood to the vertebral body, posterior elements, spinal cord, and costal structures. Spinal branch Intercostal artery Segmental arteries Aorta Anterior spinal artery Posterior branch Anastomoses
  • 155.
    Veins of theCervical and Thoracic Region The most important venous structures in the cervical spine are the internal and external JUGULAR VEINS. The internal jugular veins follow a path similar to the carotid arteries. As in other parts of the body, the veins form a network of vessels that provide compensatory circulation and a return of blood to the heart, even if there is a significant obstruction. The internal jugular veins should always be considered during any anterior cervical spine procedure. External jugular Anterior jugular Internal jugular
  • 156.
    Veins of theCervical and Thoracic Region The SUPERIOR VENA CAVA provides venous drainage of the cervical and upper thoracic spine. The segmental vessels from these regions drain into the superior vena cava. Superior vena cava
  • 157.
    Veins of theThoracic and Lumbar Internal Region jugular Superior Azygos vena cava vein Thoracic segmental veins Hemiazygos vein Lumbar segmental veins Inferior vena cava Common iliac vein (left and right)
  • 158.
    Batson’s Plexus TheAZYGOS SYSTEM is a large network of veins draining nutrient-rich blood from the intestines and other abdominal organs back to the heart. At some levels, the segmental veins drain into the azygos vein located on the right side of the abdomen, or into the hemiazygos vein located on the left side. This system of veins presents a particular challenge to the spine surgeon. The azygos system also communicates with a valveless venous network known as BATSON’S PLEXUS. When the vena cava is partially or totally occluded, Batson’s plexus provides an alternate route for blood return to the heart. Batson’s plexus
  • 159.
  • 160.
    Your Turn: Arteries Vertebral artery Aortic arch Ascending aorta Descending ? ? aorta Thoracic segmental arteries ? ? Name the Arteries Abdominal aorta ? ? Bifurcation of the aorta Lumbar ? segmental ? External iliac arteries artery Internal ? Femoral artery iliac artery ? ?
  • 161.
    Internal jugular YourTurn: Veins Superior ? Azygos ? vena cava vein Thoracic segmental veins Hemiazygos Name the Veins vein Lumbar segmental veins Inferior vena cava Common iliac veins (left and right) ? ? ? ? ? ?
  • 162.
    AAnnaattoommiiccaall SSttrruuccttuurreess RReellaatteeddttoo tthhee SSppiinnee This section discusses some of the additional organs and structures related to surgery of the spine. Vascular structures are pointed out for reference purposes. These structures can be studied by region.
  • 163.
    Anatomical Structures Relatedto the Cervical Spine Internal carotid artery Jugular vein Common carotid artery Subclavian artery Aorta Posterior View Hyoid bone Epiglottis Thyroid gland Parathyroid glands Trachea Left vagus nerve Left recurrent laryngeal nerve Superior vena cava
  • 164.
    Anatomical Structures Relatedto the Thoracic Spine Vertebral artery Trachea Esophagus Aortic arch Heart (in pericardium) Diaphragm Descending aorta
  • 165.
    Abdominopelvic Structures Relatedto the Spine Superior vena cava Accessory hemiazygos vein Hemiazygos vein Azygos vein Inferior vena cava Portal vein Diaphragm Stomach Spleen Liver (cross sectioned)
  • 166.
    Abdominopelvic Structures Relatedto the Spine Diaphragm Liver Esophagus Stomach Pancreas Parietal peritoneum (anterior abdominal wall) Abdominal aorta Small intestine Urinary bladder Rectum
  • 167.
  • 168.
    Your Turn: RelatedStructures Vertebral artery Trachea Esophagus Aortic arch Name the Structures Heart (in pericardium) Diaphragm Descending aorta ? ? ? ? ? ? ?
  • 169.
    Your Turn: RelatedStructures Superior vena cava Hemiazygos vein Azygos vein Inferior vena cava Portal vein Diaphragm Stomach Spleen Liver (cross sectioned) ? ? ? ? ? ? ? ? ? Name the Structures
  • 170.
    Your Turn: RelatedStructures ? ? ? Diaphragm Liver Esophagus ? ? Stomach Pancreas ? ? Parietal peritoneum (anterior abdominal wall) Abdominal aorta Small intestine Name the Structures Urinary bladder Rectum ? ? ?
  • 171.
    This concludes theAnatomy sseeccttiioonn ooff tthhiiss CCoouurrssee.. NNeexxtt ttoo bbeeggiinn tthhee PPaatthhoollooggyy sseeccttiioonn.. TThhaannkk YYoouu!!

Editor's Notes

  • #55 Intervertebral foramen 은 바로 위의 nerve root, 예를들면 T8-9 에는 T8 spinal nerve root가 있다.
  • #57 nucleus pulposus ~로 되어 있고 compressive resistance를 제공
  • #61 Lateral mass는 superiorly occipital condyle, inferiorly C2의 body와 articulate됨 C2 – head rotation Articular pillar는 pars interarticularis 와 superior and inferior articular process로 구성
  • #97 Lateral mass는 superiorly occipital condyle, inferiorly C2의 body와 articulate됨 C2 – head rotation Articular pillar는 pars interarticularis 와 superior and inferior articular process로 구성
  • #105 Intervertebral foramen 은 바로 위의 nerve root, 예를들면 T8-9 에는 T8 spinal nerve root가 있다.
  • #112 Facet surface는 bending motion을 가능하게 해주고, shearing force를 protection하는 articular cartilage로 덮여있음