Transition Zones Flashcards
What is/are the characteristics of occipitalization of C1
the atlas may be partially or completely fused to the occiput
what is another way of implying occipialization of C1
atlas assimilation
what is the incidence of occipitalization of C1
.1-.8% incidnece
what do the centers of ossification for the odontoid process first appear
during the last trimester in utero
when do the bilateral ossification centers for the odontoid process fuse
at or shortly after birth
what joint is formed between the odontoid process and ossification centers and the centrum of C2
the subdental synchondrosis
what is the classification of the joint formed between c2 odontoid process and the centrum
amphiarthrosis synchondrosis
ossification between the odontoid process and centrum joint of C2 first appears at what age
4 years old
a joint between the odontoid process and centrum of C2 is last identified at what age
7 years old
What is the name given to the condition in which the joint formed between the odontoid process and centrum of C2 persists beyond age 7
os odontoideum
what is the name given to the joint between the odontoid process and centrum of C2 which is still evident beyond age 7
persistent subdental synchondrosis
what is the name given to the joint formed between the tip of the dens and the odontoid process centers of ossification
tip of the dens synchondrosis
what is the classification of the joint formed between the tip of the dens and odontoid process centers of ossification
amphiarthrosis synchondrosis
at what age will the tip of the dens center of ossification appear
sometime in early adolescence
based on the age of appearance how is the tip of the dens center of ossification classified
secondary center of ossification
at what age will the tip of the dens fuse with the odontoid process
before age 12
if the joint formed between the tip of the dens and odontoid process centers of ossification persists beyond age 23, what is the condition called terminal ossicle
terminal ossicle
what is a basilar impression
persistence of the nonunion of the basilar and condylar parts of the chondrocranium such that the cartilage deforms due to the weight of the brain
what what is a basilar invagination
the upper cervical spine appears to be invaginated into the skull on x-ray analysis
What is the incidence of rib-related changes following dorsalization of C7
from one-half to two and one-half percent of the population
do patients typically present with symptoms specific for dorsalization of C7
no, they are typically asymptomatic
what is the gender bias suggested in dorsaliation of C7
female
What alterations in C7 facet orientation may accompany dorsalization
the superior articular facet of C7 may change from BUM to that of a typical thoracic BULL the inferior articular facet is unchanged
what alteration in C6 facet orientation may accompany dorsalization
C6 demonstrates a change in inferior articular facet from FoLD to ForMD superior articular facet is unchanged.
what percent of the population may demonstrate thoracic like features at C7
up to 46%
waht rib-related changes may accompany cervicalization of T1
the first rib may decrease in mean relative length or become absent
what is the incidence of cervicalization of T1 in the population
up to 28% in the population
What is the incidence of lumbar ribs in the population
over 7% of the population demonstrates lumbar ribs
what T12 facet orientation changes may accompany dorsalization
the inferior articular facet may change from convex, FoLD to flat, FoRMeD; the superior articular facet is unchanged
What is the gender bias associated with dorsalization of L1
males are 2 to 3 times more affected
what rib related changes may accompany lumbarization of T12
a significant shortening of the mean relative length of 113 mm of the twelfth rib or it becomes absent
What is the usual way of identifying the number of cervicals, thoracics and lumbar vertebrae during imaging studies
identify the vertebrae with ribs- they will be thoracics; those higher are cervicals those lower are lumbars
What is characteristic of lumbarization of S1
the failure of synostosis between S1 and S2, squaring of the vertebral body of S1 and flaring of the sacral ala
What is the incidence of sacralization of L5 in the population
41-85%
Which segment demonstrates the greatest morphological variation along the spine
L5
What articular facet changes accompany sacralization of L5
none
What is the incidence of bariation within the sacrococcygeal region in the population
up to 14%
What is characteristic of sacralization of C01
the premature fusion of Co1 to the sacrum
What is characteristic of coccygealization of S5
the separation of S5 from the sacrum and its premature fusion to Co1
What forms the spinal accessory nerve innervating the trapezius
C1-C5 cord levels contribute to the spinal root of the spinal accessory nerve
What forms the thoracodorsal nerve innervating the latissimus dorsi
verntral rami from C6-C8
Which of the muscles of the true back are innervated by the dorsal scapular nerve
levator scapulae, rhomboid major, rhomboid minor
