The neck Flashcards
Illustrate the main features of a typical cervical vertebrae
Features of the body of a typical cervical vertebra
- Small
- Broad
- Concave superiorly and inferiorly
- Uncinate process
What shape is the vertebral foramen of the cervical vertebrae and why?
- Large and triangular
- To accommodate the cervical enlargement of the spinal cord
Dscribe the orientation of the articular facets of a typical cervical vertebra
Generally, superior articular facets face posteriorly
Describe the transverse process of a typical cervical vertebra
- Directed anterior and lateral
- Have foramen transversarium for passage of vertebral arteries and veins
- Anterior and posterior tubercles have a groove for spinal nerves
Describe the spinous process of a typical cervical vertebra
Bifid
Describe the orientation of the articular facets of a typical cervical vertebra
- Superior - face superiorly and posteriorly
-
Inferior - face inferiorly and anteriorly
- Cunningham et al. (2016)
Describe the atlas (C1)
- No body or spinous process
- Vertebral foramen split into 2 spaces
What splits the vertebral foramen of the atlas and why?
Split into 2 spaces by the transverse ligament for passage of the odontoid process anteriorly and the spinal cord posteriorly.
What does the anterior part of the vertebral foramen accept and what does this form?
Anterior part accepts the dens from C2 to form the atlantoaxial joint.
Describe the transverse processes of C1 (atlas)
- Same as typical cervical but shorter
- Has foramen transversarium for vertebral arteries and veins
Describe the morphology of C1 (Atlas)
- Formed of anterior and posterior arches
- Small bump on each arch - tubercle
- Sulcus on the posterior arch where the vertebral artery passes
- Sulcus on the posterior arch where the vertebral artery passes
Illustrate the main features of C1 (atlas)
What do the superior articular facets of C1 articulate with?
Occipital epicondyles
What do the inferior articular facets of C1 articulate with?
C2 (axis)
Why are there tubercles on the medial aspect of the atlas (C1)?
- To prevent forward movement relative to C2 (axis)
- Attachment site for the transverse ligament
Illustrate the main feature of the axis (C2)
Describe the body of the axis (C2)
- Projected inferiorly overlapping the anterior part of C3
- Major upward projection - odontoid process / dens
Describe the odontoid process
- 2 articular surfaces
- 1 pointed anteriorly making contact with the anterior arch of 1
- 1 pointed posteriorly connecting the dens and the transverse ligament
What size is the vertebral foramen of the axis relative to te atlas?
Axis vertebral foramen is smaller than atlas foramen
What holds the dens in place?
Transverse ligament of the atlas
Describe the transverse and spinous processes of the axis
- Transverse - Very small compared to typical cervical vertebrae
- Spinous - bifid
Describe the orientation of the superior articular facets of the axis (C2)
Face superiorly and laterally
Describe the orientation of the inferior articular facets of the axis (C2)
Face inferiorly and anteriorly
Illustrate the features of C7
Describe the body of C7 (vertebrae prominens)
Inferior surface is flatter than typical to accommodate upper surface of T1
Describe the vertebral foramen of C7
Similar to typical - large and triangular
Describe the transverse processes of C7
- Show less prominent anterior and posterior tubercles
- Foramen does not transmit vertebral artery
Describe the spinous process of C7
- Longest of the cervical vertebrae
- Shows signs of transition to thoracic vertebrae
- Not bifid
- Much more solid and horizontally orientated (Moulton et al., 2009)
Describe the orientation of the superior articular surfaces of C7
Face superiorly and posteriorly
Describe the orientation of the inferior articular processes of C7
- Face inferiorly and anteriorly
- Orientation is better matched for thoracic vertebrae
Draw a table to compare the morphology of the cervical vertebrae
Describe the symphysis joints of the vertebral body
- Secondary cartilaginous joints
- Composed of intervertebral discs and ligaments
- Designed for strength and weight-bearing
- No IV disc between atlas and axis
What are the IV discs composed of?
- Nucleus pulposus
- Annulus fibrosis
What are the stabilising structures of the vertebral column?
- IV discs
- Epiphyseal rims of annulus fibrosis attach onto articular surface of adjacent vetebral body
- ALL and PLL - primary stabilisers which run entire length of the spine and strengthen the discs to prevent herniation
What do the vertebral bodies carry?
2/3 of the vertebral load
Compresson and tension of the discs occurs simultaneously during movement
Describe the zygaphphyseal joints
- Synovial plane
- Between superior and inferior articular processes of adjacent vertebrae
- Innervated by articular branches that arise from the medial branches of the posterior rami of the spinal nerves
Describe the stabilising structures between the vertebral arches
- Surrounded by thin joint capsule
- Accessory ligaments help stabilise the joint and unite the:
- Laminae - ligamenta flava
- Transverse processes - intertransverse ligaments
- Spinous processes - tip: supraspinous and base: interspinous ligaments
What factors permit more movement in the cervical region than any other part of the vertebrae?
- Large articular surfaces with a horizontal plane
- Loose joint capsule
What movements are possible in te cervical vertebrae?
- Flexion
- Abduction
- Adduction
- Rotation
- Joints permit gliding movements
What is the interspinous ligament like in the cervical region?
Small and inconspicuous
What are uncovertebral joints (of Luschka)?
Pseudo joints with a synovial membrane and synovial fluid, but no joint capsule
Where are uncovertebral joints (of Luschka) found?
Between the uncinate processes of cervical vertebrae 3-7 and the inferolateral uncus of the superior vertebra
What is the function of the uncovertebral joints (of Luschka)?
Reinforce the IV disc posterolaterally
What is the range of movement of the uncovertebral joints (of Luschka)?
- Flexion
- Extension
- Limited lateral rotation
What are the uncovertebral joints (of Luschka) considered as?
- By some - true diarthrodial joints
- By others - degenerative spaces of the IV discs filled with extracellular fluid and lined by a membrane
Describe the atlanto-occipital joint
- Synovial condyloid
- Between occipital condyles and superior articular processes of C1
What are the functions of the atlanto-occipital joint?
- Designed to cradle occipit
- Transmit forces from the head to the cervical spine
Describe the movements of the atlanto-occipital joint
- Flexion and extension of the head
- Slight lateral flexion and rotation
- 25° ROM in flexion and extension
- 5° ROM in rotation
Which joint is the red arrow pointing to?
Atlanto-occipital joint
Which structure is the red arrow pointing to?
Dens (odontoid process)
What are the stabilising factors of the atlanto-occipital joint?
- Nuchal ligament
- Anterior atlanto-occipital membrane
- Posterior atlanto-occipital membrane
Describe the nuchal ligament
- Continuous with supraspinous ligament
- Extends from the external occipital protuberance to the spinous process of C7
Describe the anterior atlanto-occipital ligament
- Posterior to the alar ligament
- Composed of densely packed fibres that run between the anterior margin of the foramen magnum and the superior border of the anterior arch of the atlas
Describe the posterior atlanto-occipital joint
- Broad, thin fibrous sheet
- Between the posterior margin of the foramen magnum and superior border of the posterior arch of the atlas
- Lateral borders blend with the posterior atlanto-occipital joint capsule
- Opening for the vertebral artery and suboccipital nerve
What is the atlanto-axial joint comrpised of?
- 2 synovial plane joints
- Lateral atlanto-axial between inferior facets of lateral masses of C1 and superior facets of C2
- 1 synovial pivot joint
- Medial atlanto-axial - pivot joint between dens of C2 and posterior aspect of anterior arch of atlas
Describe the movement of the atlanto-axial joint
- Allows head to be turned side to side.
- Cranium and C1 use C2 as a pivot point
- Accounts for 40-50% of cervical rotation
- Contributes 20° of to the flexion/extension ROM
What are the stabilisers of the atlanto-axial joint?
- Cruciate ligament
- Apical ligament
- Alar ligament
- Tectorial membrane
- Accessory atlanto-axial ligament
Describe the cruciate ligament
- Made up of 2 bands - longitudinal and transverse
- Longitudinal band - body of C2 → foramen magnum
- Transverse band - joins C1 lateral masses and inner margin of C1
Describe the apical ligament
- Tip of the dens → Centre of the anterior rim of the foramen magnum
- No significant added stability
- Sometimes not present
- TUBBS, 2011
Describe the alar ligament
- Side of the dens → foramen magnum
- Responsible for attaching the cranium to C1 and preventing excessive rotation
Describe the tectorial membrane
- Continuous with PLL
- Covers the dens
- Attached at the posterior surface of the axis body and the basilar groove of the occipital bone
- Limits flexion and rotation
- Tubbs, 2011
Describe the accessory atlanto-axial ligament
- From posterior body of C2 to lateral mass of C1
- Thought to be involved in craniocervical stability
List the stabilisers of the cervical spine
- Interspinous ligament
- Anterior longitudinal ligament
- Posterior longitudinal ligament
- Nuchal ligament
- Ligamentum flavum
What does the interspinous ligament connect?
Adjacent spinous processes
Where does the ALL run and what is its function?
- Runs from occipital bone on the anterior side of the vertebral body to the sacrum
- Increases the strength of the spine during flexion and extension
- Limits hyperextension
Where does the PLL run and what is its function?
- Continuation of tectorial membrane
- Passes down the posterior surface of the vertebral body
- Increases strength of spine during flexion and extension
- Limits flexion
- Reith, 2016
Where does the nuchal ligament run and what is its function?
- Continuous with the supraspinous ligament
- Extends from the external occipital protuberance to the spinous process of C7
What does the ligamentum flavum connect?
The laminae of vertebrae C2-S1
What is the range of flexion in the cervical spine?
80-90°
What is the range of extension in the cervical spine?
70°
What is the range of lateral flexion in the cervical spine?
20-45° on both sides
What is the range of rotation in the cervical spine?
90° on both sides
Range of flexion/extension at the atlanto-occipital joint
15-20°
Rotation at the atlanto-axial joint
- 50° each side
- 50% of rotation does not occur without a small degree of extension and lateral flexion
- PENNING, 1978
Arthrokinematics of the atlanto-occipital joint
- During flexion - ocipital condyles glide posteriorly and roll (rotate) anteriorly
- During extension - occipital condyles glide anteriorly and roll (rotate) posteriorly
- During rotation - ipsilateral gliding of occiput condyles
- During lateral flexion - ipsilateral gliding of occipital condyles
What is the range of craniocervical flexion?
45-50°
What is the range of craniocervical extension?
85°
What is the range of craniocervical lateral flexion?
40°
Arthrokinematics of the atlanto-axial joint
- During flexion - atlas inferior articular surfaces glide posteriorly and roll anteriorly
- During extension - atlas inferior articular surfaced glide anteriorly and roll posteriorly
-
During rotation - while dens remains static, the atlas rotates towards the side of rotation
- The ipsilateral inferior articular surface slides posteriorly, while the contralateral slides anteriorly
Arthrokinematics of the cervical spine - C2-C7
- During flexion - upper vertebrae glides anteriorly and rolls anteriorly
- During extension - upper vertebrae glides posteriorly and rolls posteriorly
- During lateral flexion - always occurs with same side rotation; ipsilateral inferior articular surface of the vertebrae glides posteriorly and inferiorly, contralateral glides anteriorly and superiorly
- During rotation - always occurs with same side lateral flexion, ipsilateral inferior articular surface of vertebrae glides posteriorly and inferiorly, contralateral glides anteriorly and superiorly
What are the three types of occipitocervical dislocation?
- Anterior occiput dislocation
- Longitudinal dislocation
- Posterior occiput dislocation
- Kasliwal et al. (2016)
AKA atlanto-occipital dislocation
Occipitocervical Dislocation
- Follows complete or near complete ligamentous disruption
- Common cause - pedestrian hit by high speed vehicle
- As a result of hyperlexion
Occipital condyle fracture
- Reported in 3-15% of cervical trauma patients
- Type 1 - impaction fracture of the condyles, due to compression
- Type 2 - Basilar fracture extending to the condyle, due to direct blow to skull
- Type 3 - avulsion fracture at the site of the alar ligament attachment, due to forces lateral bending and rotation.
- Alcelik et al. (2006)
Atlas fractures
- Due to hyperextension, lateral compression and axial compression.
Odontoid fracture
- Due to high energy trauma or low energy fall
- Type 1 - tip of odontoid
- Type 2 - junction of odontoid base and vertebral body
- Type 3 - fracture extends into the body of C2
Traumatic spondylolisthesis of the axis
- High energy trauma involving hyperextension and axial loading
- Known as HANGMAN’S FRACTURE
- Several types
- Generally involves fracture of pars interticularis on both sides of C2
Where is the pars interticularis?
Anterior to the lamina, posterior to the pedicles
Traumatic spondylolisthesis of the axis
- HANGMAN’S FRACTURE
- Type 1 - <3mm anterio-posterior deviation
- Type 2 - >3mm antero-posterior deviation
- Type 3 - type 1 with bilateral facet dislocation
- Govender and Charles, 1987
Subaxial cervical spine injuries
- Flexion compression injuries - most common at C5-6
- Flexion-distraction injuries - most common at C6-7
