Ligaments and Joints of the Vertebral Column
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vertebrae | Main Anatomy
Index | Intrinsic back muscles
Last updated 30 March 2006
Joints of the Vertebral Column
- The vertebrae from C2 to S1 articulate with one another
at joints between their bodies and between their
of the Vertebral Bodies (pp. 342-7)
- The anterior intervertebral joints are secondary
cartilaginous joints (symphysis) which are
designed for strength and weight bearing.
- The articulating surfaces of the adjacent vertebrae are
covered with hyaline cartilage and are connected by a
fibrocartilaginous intervertebral disc and ligaments.
- The intervertebral discs
provide the strongest attachment between the bodies of
the vertebrae. In addition to these discs, strong
anterior and posterior longitudinal ligaments unite the
- In the cervical and lumbar regions, the discs are thick
anteriorly making them wedge shaped. This structure of
the discs is related to the normal curvatures in these
The anterior longitudinal ligament (p. 342)
- This is a strong, broad fibrous band that covers and
connects the anterior aspects of the bodies of the
vertebrae and intervertebral discs.
- This ligament is thickest when opposite the discs.
- It extends from the pelvic surface of the sacrum to the
anterior tubercle of C1 (atlas) and
the occipital bone
of the skull, anterior to the foramen magnum.
- The fibres of this ligament firmly attach to the
intervertebral discs and the periosteum of the vertebral
- This strong ligament helps to maintain the stability of
the joints between the vertebral bodies and helps prevent
hyperextension of the vertebral
The posterior longitudinal ligament (p. 342)
- This is a narrower, weaker band than the anterior
longitudinal ligament. It runs along the posterior aspect
of the vertebral bodies, within the
- It is broadest superiorly where it is continuous with the
which is attached to the occipital bone on the
interior aspect of the foramen magnum.
- It is attached to the intervertebral discs and the
posterior edges of the vertebral bodies from the axis
(C2) to the sacrum.
- The posterior longitudinal ligament also helps to prevent
hyperflexion of the vertebral
column and posterior protrusion of the nucleus
pulposus of the disc.
Intervertebral Discs (p. 342)
- These are plates of fibrocartilage
corresponding to the shape to the articular surfaces of
the vertebral bodies.
- The discs play a leading role in
weight bearing and a lesser role in movement.
- Each disc is composed of an external anulus
fibrosus, which surrounds the internal
gelatinous nucleus pulposus.
- The anuli fibrosi insert into the smooth, rounded rims on
the articular surfaces of the vertebral bodies.
- The nuclei pulposi contact the hyaline
cartilage plates, which are attached to the
rough articular surfaces of the vertebral bodies.
- There is no disc between C1 (atlas)
and C2 (axis). The most inferior functional
disc is between L5 and S1.
Fibrosus (p. 342)
- This is the fibrous ring of the intervertebral disc. It
is composed of concentric lamellae
of fibrocartilage, which run obliquely from
one vertebra to another.
- Some fibres in one lamella are at right angles to those
in the adjacent ones. This arrangement, while allowing
movement between vertebrae, provides a very strong bond
- The lamellae are thinner and less numerous posteriorly
than they are anteriorly or laterally.
The Nucleus Pulposus (pp. 342, 347)
- This is the central core of the intervertebral disc. It
is more cartilaginous than fibrous
and is normally highly elastic.
- It is located more posteriorly than centrally and has a
high water content until old age.
- The nucleus pulposus (L. pulpa, fleshy) acts like
a shock absorber for axial forces and like a semi-fluid
ball bearing during flexion, extension, rotation, and
lateral flexion of the vertebral column.
- It becomes broader when compressed.
- The nucleus pulposus is avascular.
It receives its nourishment by diffusion from blood
vessels at the periphery of the anulus fibrosus and from
the adjacent surfaces of the vertebral bodies.
- Protrusions of the nucleus pulposus
usually occur posterolaterally, where the anulus fibrosus
is weak and poorly supported by the posterior
longitudinal ligament. The protruding part of the nucleus
pulposus may compress an adjacent spinal nerve root,
causing severe lower back pain and/or leg pain.
Joints of the Vertebral Arches (pp.
Joints (facet joints)
- These are synovial joints between the interior articular
process of superior vertebrae and the superior articular
process of inferior vertebrae. These plane joints are
known as zygapophyseal joints
- The flat surfaces of the articular facets are covered
with hyaline cartilage.
- Each joint is surrounded by as thin, loose articular
capsule that is attached to the articular margins of the
- The fibrous capsules are longer and looser in the
cervical region than in the thoracic and lumbar regions.
The fibrous capsule of each joint is lined with a
- The facet joints permit gliding movements between the
- In the cervical and lumbar regions, these joints bear
some weight, sharing this function with the
- These joints control flexion, extension, and rotation of
adjacent cervical and lumbar vertebrae.
- Most of the movement in the vertebrae occur in these two
Accessory Ligaments of the Intervertebral
Joints (p. 348)
Flava (p. 348)
- The laminae of adjacent vertebral arches are joined by
broad, elastic bands called ligamentum
flava (yellow ligaments), which extend almost
vertically from the lamina above to the lamina below.
- The ligamentum flavum was given its name because of its
fibres consist mainly of yellow elastic tissue (L. flavus,
- The ligaments are attached superior to the anterior
surfaces of the inferior borders of a pair of laminae,
and inferiorly to the posterior surfaces of the superior
border of the next succeeding pair.
- Some of their fibres extend to the articular capsule of
the facet joints and contribute to the posterior
boundaries of the intervertebral foramina.
- The ligamentum flava help to preserve the normal
curvature of the vertebral column and to straighten the
column after it has been flexed.
Interspinous and Supraspinous Ligaments (p. 348)
- Weak interspinous ligaments and a strong cord-like
supraspinous ligament joint adjacent spinous processes.
- These ligaments are represented superiorly by the ligamentum nuchae, a
triangular medial septum between the muscles on each side
of the posterior aspect of the neck.
Ligaments (p. 348)
- These are ligaments connecting adjacent transverse
processes, consists of a few scattered fibres, except in
the lumbar region where they are membranous and more
The Craniovertebral Joints
- The suboccipital joints are between the skull and C1
(atlas), and between C1 and C2 (atlas and axis). They are
called the atlanto-occipital and atlanto-axial joints.
- The main differences between these joints and others in
the vertebral column are (1) they are synovial
only, there are no
intervertebral discs, and (2) there are no zygapophyseal joints (facet).
Atlanto-occipital Joints (pp. 349-50)
- These articulations are between C1 (atlas) and the
occipital condyles. They permit nodding
of the head (i.e., the flexion and extension
of the neck that occurs when indicating approval).
- The atlanto-occipital joints, one on each side, are
between the superior articular facets on the lateral
masses of C1 and the occipital condyles.
- They are condyloid type of synovial
- They have thin, loose articular capsules that are lined
with synovial membrane.
- The skull and C1 are also connected by anterior and
membranes, which extend from the anterior and
posterior arches of C1 to the anterior and posterior
margins of the foramen magnum.
- They prevent excessive movement of the atlanto-occipital
- The transverse ligament of the
atlas is a strong band extending between the
tubercles on the lateral masses of C1 vertebrae.
- It holds the dens of C2 against the anterior arch of C1.
There is a synovial joint between them.
- Vertically oriented superior and inferior bands pass from
the transverse ligament to the occipital bone superiorly
and to the body of C2 inferiorly.
- They form the cruciform ligament
(L. crux, cross) which was given this name because
of its resemblance to a cross.
- The alar ligaments
extend from the sides of the dens to the lateral margins
of the foramen magnum.
- These short, strong, rounded cords attach the skull to C2
- They check rotation and
side-to-side movements of the head.
Atlanto-axial Joints (p. 350)
- These are synovial joints between C1 and C2 vertebrae.
There are two lateral joints and one medial joint.
- The movement of these joints is
rotation, which allows the head to be turned
from side to side.
- During this movement, the skull and C1 rotate as a unit
- Alar ligaments prevent excessive rotation of these
- Movements of the joints between the skull and C1 and
between C1 and C2 vertebrae are augmented by the
flexibility of the neck owing to movements of the joints
of the vertebral column in the middle and inferior
- During rotation of the head, the dens of C2 is held in a
collar formed by the anterior arch of the atlas and the
transverse ligament of the atlas.
- The articulation of the dens with
C1 is a pivot joint.
Movements of the Vertebral Column (p. 350)
- The range of movement of the vertebral column varies
considerably according to the individual.
- The extreme extension exhibited by acrobats who can put
their heads between their lower limbs would be hyperextension in almost
- The normal range of movement is limited by (1) the
thickness and compressibility of the intervertebral
discs, (2) the resistance of the muscles and ligaments of
the back, and (3) the tension of the articular capsules
of the zygapophyseal (facet) joints.
- Movements between adjacent vertebrae take place on the
resilient nuclei pulposi of the intervertebral discs and
at the facet joints.
- Although movements between adjacent vertebrae are
relatively small, especially in the thoracic region, the
summation of all of the small movements produces a
considerable range of movements of the vertebral column
as a whole.
- Movements of the vertebral column are
freer in the cervical and lumbar regions than elsewhere.
These regions are also the most frequent sites of aches,
pain and serious injuries.
- The thoracic region of the
vertebral column is relatively stable owing to
its connection to the sternum via the ribs and costal
cartilages. In addition, the intervertebral discs are
slightly thinner and their spinous processes overlap.
- Extension is most marked in the
lumbar region and generally is more extensive
- Flexion is greatest in the cervical
region and is almost non-existent in the
- During flexion of the lumbar region, the nucleus pulposus
moves posteriorly, putting tension on the posterior part
of the anulus fibrosus.
- This is the major reason that posterolateral herniations
of the nucleus pulposus through the anulus fibrosus are
most common in the lower lumbar and lumbosacral regions.
- Lateral flexion is greatest in the
lumbar region; it is restricted by the ribs in
the thoracic region. Because of the greater rotation and
gliding movements between its vertebrae, rotation is most marked in the thoracic