The cervical and thoracic spine Flashcards
Which are the atypical vertebrae
C1 C2 C7
What is C1 also known as
Atlas
Structure of C1
-Bony ring
-Anterior and posterior arch connected by 2 lateral masses
-widest cervical vertebrae
No vertebral body and no spinous processes
What permits nodding
Atlanta-occipital joint- contributes 50% of the total range of flexion and extension of the head and neck
What is C2 also known as
Axis
What is responsible for 50% of total rotation of the head
Atlanta-axial joint
What is the odontoid process
also known as the dens or odontoid peg, projects vertically upwards from the body of the axis.
This is the vestigial remnant of the body of C1.
What prevents horizontal displacement of the atlas on the axis
The odontoid process and transverse ligament together p
Features of C7
- vertebra prominens
- longest spinous process
- not bifid
- large transverse process
- small foramen transversarium which only transmits the accessory vetebral veins
Where do each spinal nerve exit in the cervical spine
In the cervical region, however, each spinal nerve exits above its respectively- named vertebral body until the C7/T1 junction, where the C8 nerve root is the ‘exiting nerve root’
What is the ligamentum nuchae
Thickening of the supraspinous ligament
Extends from the external occipital protuberance of the skull and the median nuchal line to the spinous process of C7
What is the role of ligaentum nuchae
• To maintain the secondary curvature of the cervical spine • To assist the cervical spine to support the weight of the head
• In continuity with the supraspinous ligament of the thoracic and lumbar
spine, to be a major site of attachment of the muscles in the neck and trunk
e.g. trapezius, rhomboids
Features of the thoracic spine
• Medium-sized, heart-shaped vertebral bodies
• A vertebral foramen that is small and circular
• Prominent transverse processes with transverse costal facets that allow for
articulation with ribs (except T11 and T12)
• Either demi-facets (T2-T8) or whole facets (T9-T10) on the sides of the
vertebral bodies for articulation with the heads of the ribs. [T11-12 have
whole facets on the pedicles instead.
• Long, spinous processes, angulated inferiorly
• Articular facets that are orientated at 20° to the coronal plane and at 60° to
the axial plane. (The superior articular processes face
posterolaterally and inferior articular processes face anteromedially; this
orientation permits rotation and lateral flexion, but prevents flexion and
extension).
Why does the thoracic spine have limited flexibility
The thoracic spine has limited flexibility compared with the cervical and lumbar spine because the rib cage is connected to each segment of the thoracic spine
Which thoracic vertebra have hole facets
• T1: The superior costal facet is not a demi-facet, as this is the only vertebra
to articulate with the 1st rib (figure 7.18). The inferior costal facet is a demi- facet as per the typical thoracic vertebrae.
• T9 and T10: Whole costal facets articulate with the 9th and 10th rib
respectively. These facets extend from the vertebral body to the pedicle.
• T11 and T12: Whole costal facets are located on the pedicles
How does the spinous process change from T1 Down to T12
The spinous process also becomes shorter and less oblique from T1 down to T12, so that the T12 spinous process more closely resembles that of a lumbar vertebra
What is cervical spondylosis
chronic degenerative osteoarthritis affecting the intervertebral joints in the cervical spine.
age- related disc degeneration which is followed by marginal osteophytosis (osteophyte formation adjacent to the end plates of the vertebral bodies) and facet joint osteoarthritis.
What is radiculopathy
The resultant narrowing of the intervertebral foramina can put pressure on the spinal nerves leading to radiculopathy. Symptoms of radiculopathy include dermatomal sensory symptoms (e.g. paraesthesia, pain), and myotomal motor weakness.
Myelopathy
degenerative process leads to narrowing of the spinal canal, this may instead put pressure on the spinal cord
What is a Jefferson’s fracture
Jefferson’s fracture is a fracture of the anterior and posterior arches of the atlas vertebra (C1). The mechanism of injury is axial loading
Hangman’s fracture
In a Hangman’s fracture, the axis vertebra (C2) is fractured through the pars
interarticularis (the region between the superior and inferior articular processes).
What causes a hangman’s fracture
The mechanism of injury is usually forcible hyperextension of the head on the neck; historically by ‘hanging’ and more recently in road traffic collisions.
What causes fracture of the odontoid process
caused by either flexion or extension injuries. The most commonly seen mechanism is an elderly patient with osteoporosis falling forwards and impacting their forehead on the pavement.
Why do Whiplash injuries occur
The head accounts for 7-10% of the total body weight. It is balanced on the cervical
spine, which has high mobility and therefore low stability (as mobility and stability
of joints are inversely related
Myofasical pain syndrome
can sometimes develop as a secondary tissue response to disc or facet-joint injury. There is a surprisingly high prevalence of chronic pain that results from whiplash injury, although secondary gain
What will be compressed in cervical disc prolapse
Exiting nerve root
Cervical myelopathy
Cervical myelopathy is spinal cord dysfunction due to compression of the cord. It is caused by narrowing of the spinal (vertebral) canal.
What caused cervica myelopathy
degenerative stenosis of the spinal canal caused by cervical spondylosis
Hoffmans test
the doctor holds the patient’s middle finger at the middle phalanx and flicks the finger nail. If there is no movement in the index finger or thumb after this motion, the patient has a negative Hoffman’s sign (normal). If the index finger and thumb move, the patient has a positive Hoffman’s sign (abnormal).
Babinski sign
the lateral side of the sole of the foot is stroked with a blunt instrument from the heel towards the toes. Normally in children over the age of approximately 2-3 years and adults, the response is flexor in that the toes flex downwards towards the sole (plantarflex). In a positive (abnormal) Babinski sign, the hallux dorsiflexes and the toes fan out. This suggests damage to the long tracts of the spinal cord.
Which nerve is damaged in a disc prolapse of Cx/ CX + 1
CX + 1
