M1.1 — 3 Cx 0-4 Flashcards
(31 cards)
how many primary ossification centers are in vertebras? where?
3
- midline centrum = vertebral body
- 2 posterolateral = 2 halves of the neural arch and posterior vertebral bodies
what is the neurocentral joint?
where the ossification centers meet in the posterior vertebral body
generally, when does ossification start in vertebrae? and fuse?
in latter half of embryonic period
fuse around time of birth
how many secondary ossification centers are in vertebrae? where? when do they appear?
at least 9
- ring epiphysis (endplates) (2)
- tips of TP (2)
- tip of SP
- each articular process (4)
- *Lx also has them at mammillary processes (2)
puberty
generally, when do secondary ossification centers of the vertebrae fuse?
18-25 yo
in the normal Cx vertebra the vertebral bodies are ____ shaped, they have a ___ intervertebral foramen, a small ____ vertebral canal, ____ SP
oval
wide
triangular
bifid
what are the atypical Cx spine vertebrae’s?
C1, C2 and C7
how many ossification centers are in C1? where? when do they fuse?
3
- 1 anterior (may be up to 4) (fuses 6-8 yo)
- 2 lateral masses (arise in week 7 gestation) (fuses 3-4 yo)
what is spina bifida occulta of C1? how common is it? what are the symptoms and associations?
- failure of posterior fusion - “spondyloschisis”
- 10-20% of pop
- asymptomatic
- no associated abnormalities
What is Split Atlas of C1? symptoms?
- bipartite atlas spanned by fibrous tissue
- asymptomatic but may have neck P and rarely spinal myelopathy
- may look like jefferson fracture
What is atlantooccipital assimilation? symptoms? what anomalies is it associated with?
atlas doesn’t separate from occiput - may be complete or incomplete connected by fibrous band
asymptomatic
C2-3 block
Basilar invagination
Cleft Palate
Cervical Ribs
Upper Cx instability
What is agenesis of the C1 posterior arch? what other findings are associated?
partial or complete lack of ossified posterior arch and posterior tubercle (fibrocartilage arch present)
hypertrophy of anterior tubercle, enlargement of C2 SP, may have upper Cx instability
What is a Chiari Malformation?
congenital caudal displacement of the cerebellum and brainstem
in Chiari I, what is abnormal? what else can occur?
cerebellar tonsils
syringomyelia present in 25-50%
what is the most common Chiari type?
Chiari I
what is abnormal in Chiari I.5
cerebellar tonsils and brain stem
What is abnormal in Chiari II? what else is associated with it?
medulla, 4th ventricle and cerebellar vermis
- lumbosacral myelomeningocele
- can result in hydrocephalus
What is abnormal with Chiari III? what is associated?
medulla, 4th ventricle, cerebellar vermis, with occipital and/or high Cx encephalocele
severe nervous system problems - intelligence, seizures, muscle issues
What is abnormal with Chiari IV? how common is it?
severe cerebellar hyperplasia without displacement of cerebellum
rare- survival is low
What is abnormal with Chiari V?
- absent cerebellum
- herniation of occipital lobe thought the foramen magnum
what is abnormal with Chiari 0?
syrinx without cerebellar tonsillar or brain stem discent
What are symptoms of Chiari I?
HA (posterior head or upper neck)
hoarseness or trouble speaking
dysphagia
nystagmus
sleep apnea
weakness or abnormal movements
balance issues
abnormal reflexes
scoliosis (usually with syringomyelia)
What is McRae’s line?
- line from Basion or Opisthion to assess chiari malformation
- the tonsils should be below the line by no more than 5mm in children and 3mm in adults
how many primary ossification centers are in the Axis (C2)? where? when do they appear and fuse?
5
- 2 vertebral arch (appear 7-8th week gestation, fuse posterior by 3 yo)
- vertebral centrum/body (appear 4-5 week gestation)
- 2 dens (appear 6 month gestation, fuses before birth, fuses to vertebral body by 3-6 yo)
