JOINTS OF THE SKULL, SPINE & PELVIS

Kaan Yücel M.D., Ph.D. 24.02.2014 Monday

JOINTS OF THE CRANIUM

SUTURAE – SUTURES(S)

SUTURAE form of articulation

margins of bones united by a thin layer of fibrous tissue

LAMBDOID SUTUREParietal bonesOccipital bones

CORONAL SUTUREFrontal bonesParietal bones

SAGITTAL SUTUREParietal bones

TEMPOROMANDIBULAR JOINTa modified hinge type of synovial jointMovements

gliding (translation) small degree of rotation (pivoting) flexion (elevation) extension (depression)

TEMPOROMANDIBULAR JOINT

mandibular fossa & articular tubercle of temporal bone head of the mandible

articular disc of the TMJ

JOINTS OF THE VERTEBRAL COLUMN

Spine by Sara Young

JOINTS OF THE VERTEBRAL COLUMN

1) Craniovertebral (atlanto-axial and atlanto-occipital) joints2) Costovertebral joints 3) Sacroiliac joints

Symphyses between vertebral bodies n=2 1 above, 1 belowSynovial joins between articular processes n=4 2 above, 2 below

a total of 6 joints between two vertebrae

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JOINTS OF THE VERTEBRAL BODIES

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Joint type: symphyses (secondary cartilaginous joints) designed for weight-bearing and strengthA layer of hyaline cartilage on each vertebral bodyAn intervertebral disc between these layers

an outer anulus fibrosus surrounds a central nucleus pulposus.

Anulus fibrosusan outer ring of collagen surroundinga wider zone of fibrocartilage arranged in a lamellar configuration.

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core of the intervertebral disc fills the center of the intervertebral discgelatinousabsorbs compression forces between vertebrae.

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Nucleus pulposus L. pulpa, fleshy

semifluid nature responsible for much of the flexibility & resilience of the intervertebral disc and of the vertebral column as a whole

INTERVERTEBRAL DISCS

Provide strong attachments between the vertebral bodiesUnite vertebral bodies into a continuous semirigid column Form the inferior ½ of anterior border of the intervertebral foramen. 20-25% of the length (height) of the vertebral column.

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Thickness of the discs vertebral column descends

The range (amount) of movement relative thickness to body

greatest @ cervical & lumbar regions, movements of vertebral column greatest thickness most uniform in the thoracic region

INTERVERTEBRAL DISCS

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L4

L5

FUNCTIONS OF INTERVERTEBRAL DISCS

Thanks to the semifluid nature One vertebra rock forward or backward on another during flexion & extension

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JOINTS OF THE VERTEBRAL ARCHES

ZYGAPOPHYSIAL JOINTS, FACET JOINTS

plane synovial joints between superior & inferior articular processes of adjacent vertebrae.

@ cervical region articular capsule especially thin wide range of movement

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JOINTS OF THE VERTEBRAL ARCHES

ZYGAPOPHYSIAL JOINTS, FACET JOINTSpermit gliding movements between articular processes

shape & disposition of the articular surfaces determine the types of movement possible.

Accessory ligaments unite the laminae, transverse processes, and spinous processes and help stabilize the joints.

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LIGAMENTS OF THE VERTEBRAL COLUMNJoints between vertebrae

reinforced & supported by numerous ligamentspass between vertebral bodies

interconnect components of vertebral arches.

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LIGAMENTS OF THE VERTEBRAL COLUMN

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Anterior & posterior longitudinal ligaments Ligamenta flava Supraspinous ligament & ligamentum nuchae Interspinous ligaments

between two laminae

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Anterior longitudinal ligament Posterior longitudinal ligamentFrom base of the skull to anterior surface of sacrum Along its length attached to vertebral bodies and intervertebral discs

Tectorial membranePosterior longitudinal ligament connecting axis to base of the skull

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Ligamenta flava/Ligamentum flavum

Between posterior surface of the lamina on the vertebra belowanterior surface of the lamina of the vertebra above

resist separation of the laminae in flexion. assist in extension back to the anatomical position.

connects tips of the spinous processes from vertebra C7 to the sacrum

From vertebra C7 to the skull becomes structurally distinct

ligamentum nuchae

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Supraspinous ligament

triangular, sheet-like structure in the median sagittal plane

External occipital protuberance to magnum

tip of spinous process of C7

deep side attached to posterior tubercle of vertebra C1 & spinous processes of other cervical vertebrae.

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Ligamentum nuchae

supports the head.resists flexion .facilitates returning the head to the anatomical position.provide attachment for adjacent muscles broad lateral surfaces & posterior edge

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Ligamentum nuchae

between adjacent vertebral spinous processes

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Interspinous ligaments

from base to apex of each spinous process

CRANIOVERTEBRAL JOINTS

a wider range of movement than in the rest of the vertebral column.

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atlanto-occipital jointsbetween atlas (C1) & occipital (condyle) boneatlanto-axial jointsbetween atlas (C1) & axis (C2)

Synovial joints with no intervertebral discs

ATLANTO-OCCIPITAL JOINTS

nodding of the head, “yes” movementalso sideways tilting of the head.Main movement flexion, with a little lateral flexion and rotation.

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Superior articular surfaces of lateral masses Occipital condyles

LIGAMENTS OF ATLANTO-OCCIPITAL JOINTSAnterior atlanto-occipital membrane (continuation of anterior long.lig.)connects anterior arch of the atlas to anterior margin of the foramen magnumPosterior atlanto-occipital membrane (similar to the ligamentum flavum) connects the posterior arch of the atlas to the posterior margin of the foramen magnum.

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help prevent excessive movement of the atlanto-occipital joints

ATLANTO-AXIAL JOINTS

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Right & left lateral atlantoaxial joints between inf. facets of lateral masses of C1 & superior facets of C2

Median atlantoaxial jointbetween dens of axis & anterior arch of atlas

plane

IVOT

MOVEMENTS OF ATLANTO-AXIAL JOINTS

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During rotation of the headDens/pivot held in a collar

anteriorly anterior arch of atlasposteriorly transverse ligament of atlas

between tubercles on medial sides of lateral masses of atlas

Cranium & atlas rotate on axis as a unit.

Head turns from side to side, disapproval (“no” movement).

LIGAMENTS OF ATLANTO-AXIAL JOINTS

Superior and inferior longitudinal bands Apical ligament Alar ligamentsCruciate ligament of the atlasTectorial membrane (Membrana tectoria)

.

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COSTOVERTEBRAL JOINTS

essential for altering the volume of the thoracic cavity during breathing

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A typical rib articulates with: bodies of adjacent vertebrae joint with the head of the rib transverse process of its related vertebra costotransverse joint Necks rotate around their longitudinal axis mainly in upper ribsRibs ascend descdend relative to the spine mainly in lower ribs

Joint with head of rib

divided into two synovial compartments by an intra-articular ligament

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Head of the ribTwo facets face of articulation1- with superior facet of its own vertebra2- with inferior facet of the vertebra above

Costotransverse joints

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Slight gliding movements

MOVEMENTS OF THE VERTEBRAL COLUMN

Range of movement according to the region and the individual Mobility primarily from compressibility & elasticity of the intervertebral discs Normal range of movement reduced by 50% or more as a result of agingMovements by the vertebral column

FlexionExtensionLateral flexionRotationCircumduction

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MOVEMENTS OF THE VERTEBRAL COLUMN

Movements in a specific region (cervical, thoracic, and lumbar) determined by

shape & orientation of joint surfaces on the articular processes & on the vertebral bodies

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JOINTS OF THE PELVIS

The primary joints Sacroiliac joints & pubic symphysis

Sacroiliac joints link axial skeleton & inferior appendicular skeleton.Lumbosacral & sacrococcygeal joints, although joints of the axial skeleton, are directly related to the pelvic girdle. Strong ligaments support and strengthen these joints.

Strong, weight-bearing compound joints An anterior synovial joint between the earshaped auricular surfaces of the sacrum & iliumA posterior syndesmosisbetween the tuberosities of the same bonesDiffer from most synovial joints limited mobility is allowed, a consequence of their role in transmitting the weight of most of the body to the hip bones.

SACROILIAC JOINTS

Weight from the axial skeleton:Sacroiliac ligaments ilia

Femurs –during standing- Ischial tuberosities –during sitting-

Sacrum is actually suspended between the iliac bonesFirmly attached to iliac bones by posterior and interosseous sacroiliac ligaments.

Formed by posterior sacroiliac ligaments

Passes from posterior ilium, lateral sacrum & coccyx to ischial tuberosity

Transforms the sciatic notch of the hip bone into a large sciatic foramen.

Sacrotuberous l igament

Sacrospinous ligament from lateral sacrum & coccyx to ischial spinesubdivides sciatic foramen into greater and lesser sciatic foramina.

Most of the time, movement at the sacroiliac joint is limited by interlocking of the articulating bones and the sacroiliac ligaments.

By allowing only slight upward movement of the inferior end of the sacrum relative to the hip bones, resilience is provided to the sacroiliac region when the vertebral column sustains sudden increases in force or weight.

Secondary cartilaginous joint A fibrocartilaginous interpubic disc & surrounding ligaments uniting the bodies of the pubic bones in the median plane. Interpubic disc wider in women.

PUBIC SYMPHYSIS

superior & inferior margins of the symphysisSuperior pubic ligament connects the superior aspects of the pubic bodies and interpubic disc.

Inferior (arcuate) pubic ligament connect the inferior aspects of the joint componentsround off the subpubic angle as it forms the apex of the pubic arch.

Superior & inferior pubic ligaments

L5 & S1 articulate Anterior intervertebral (IV) joint formed by L5/S1 IV disc

between their bodies &

2 posterior zygapophysial joints (facet joints) between the articular processes of these vertebrae

Fan-like iliolumbar ligaments radiate from the transverse processes of the L5 vertebra to the ilia.

LUMBOSACRAL JOINTS

Secondary cartilaginous joint with an intervertebral disc. Fibrocartilage & ligaments join apex of the sacrum base of coccyx.

Anterior & posterior sacrococcygeal ligaments long strands that reinforce the joint.

SACROCOCCYGEAL JOINT