W1: Spine Flashcards
How many vertebrae?
33
cervical 7
thoracic 12
lumbar 5
sacral 5
coccygeal 3-4 fused
Draw and label standard vertebrae
Distinguishing features of cervical
Bifid spinous process – the spinous process bifurcates at its distal end.
Exceptions to this are C1 (no spinous process) and C7 (spinous process is longer than that of C2-C6 and may not bifurcate).
Transverse foramina – an opening in each transverse process, through which the vertebral arteries travel to the brain.
Triangular vertebral foramen
Small body - not a lot of weight
Discuss C1
Atlas
Doesnt have a body or a spinous process
Supports occipital bone
Transverse ligament of the atlas - maintains odontoid process in contact with the anterior arch
Discuss C2
Prominent superior projection - dens axis or odontoid process
Discuss C7
Separation of S1 from the sacrum is termed “lumbarisation”, while fusion of L5 to the sacrum is termed “sacralisation”. These conditions are congenital abnormalities.
What passes through transverse foramina in cervical?
Discuss general thoracic
The spinous processes of thoracic vertebrae are oriented obliquely inferiorly and posteriorly
Circular vertebral foramen
Costal facets/demi facets
Which rib is an exception when it comes to articulation?
Discuss general lumbar
triangle shaped foramen
Their spinous processes are shorter than those of thoracic vertebrae and do not extend inferiorly below the level of the vertebral body
Interlocking facetts preventing rotation
Stabilisation of L5 & sacrum
Scotty dog on radiograph is transverse process
Main site of herniations
Discuss general sacrum
Anterior aspect:
Transverse ridge
Wings = ala of sacrum
Auricular surface of the sacrum - forms sacroiliac joint
Posterior aspect:
Posterior sacral and lateral sacral crests
Bottom = sacral hiatus
Sacral congenital abnormalities
Separation of S1 from the sacrum is termed “lumbarisation”, while fusion of L5 to the sacrum is termed “sacralisation”. These conditions are congenital abnormalities.
Discuss ligaments present throughout vertebral column
Anterior and posterior longitudinal ligaments: Long ligaments that run the length of the vertebral column, covering the vertebral bodies and intervertebral discs.
Ligamentum flavum: Connects the laminae of adjacent vertebrae.
Interspinous ligament: Connects the spinous processes of adjacent vertebrae.
Supraspinous ligament: Connects the tips of adjacent spinous processes.
(Note: In the cervical spine, the interspinous and supraspinous ligaments thicken and combine to form the nuchal ligament).
What is the alar ligament?
Joins dens of C2 to lateral margins of foramen magnum
Cruciform ligament
The cruciate ligament of the atlas (also known as the cruciform ligament) is an important ligamentous complex that holds the posterior dens of C2 in articulation at the median atlantoaxial joint. It lies behind a large synovial bursa (surrounded by loose fibrous capsule) and consists of two bands:
longitudinal band: attaches the body of the C2 (axis) to the clivus and foramen magnum in the midline, lying between the apical ligament and tectorial membrane. It is relatively weak and hence does not contribute any significant stability.
transverse band (also known as the transverse atlantic or atlantal ligament): attaches to a small tubercle on the medial cortex of the C1 (atlas) lateral masses on both sides anterior to the tectorial membrane and dura. It passes posterior to the dens, with a small intervening synovial capsule, fixing the dens to the posterior margin of the anterior arch of the atlas. It is the strongest ligament in the whole spine 2 and arguably the most important!
With the alar ligament, the transverse band is the primary stabiliser of the atlantoaxial joint 2.
Whiplash injury
Hyperflexion + hyperextension of cervical
Hangman fracture
bilateral fracture through the neural arch of the 2nd cervical vertebra with or without dislocation of the body of the axis upon that of the 3rd cervical vertebra.
Extrinsic muscles of the back
Posterior-axioappendicular muscles controlling upper limb movements
Includes the rhomboids, levator scapulae, trapezius and latissimus dorsi
Discuss rhomboids
Rhomboid major and rhomboid minor
Retract the scapula
Discuss levator scapulae
Scapular motion - elevation
Transverse processes –> medial border of scapula