Transition Zone Characteristics Flashcards
What is/are the characteristic(s) of occipitalization of C1
The atlas may be partially or completely fused to the occiput
What is another way of implying occipitalization of C1
Atlas assimilation
What is the incidence of occipitalization of C1
0.1% - 0.8%
When do the centers of ossification for the odontological 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 forms between the odontoid process ossification centers and the centrum of C2
The subdental 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 joint of C2 first appears 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 os odontoideum?
A persistence beyond age 7 of the joint formed between the centrum and odontoid process centers of ossification
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 of the joint formed betweeen the tip of the dens and the odontoid process centers of ossification
Tip of the dens synchondrosis
At what age will the tip of the dens center of ossification appear
Sometime in early adolescence
At what age will the tip of the dens fuse with the odontoid process
Before age 12q
What is a terminal ossicle?
A persistence beyond age 12 of the joint formed between the tip of the dens and odontoid process centers of ossification
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 is a basilar invagination
The upper cervical spine appears to be invaginated into the skull on x-ray analysis
What is/are the characteristics of dorsalization of C7
The addition of a rib and changes in superior articular facet orientation are typical
What is the incidence of rib-related changes following dorsalization of C7
1.5% - 2.5% of the population
What is the gender bias suggestion in dorsalization of C7
Female
What percent of the population may demonstrate thoracic-like features at C7
Up to 46%
What rib-related changes may accompany cervicalization of T1
The first rib may decrease in mean relative length of become absent
What will result from fusion of a short rib to the T1 transverse process
The transverse foramen
What is the incidence of cervicalization of T1 in the population
Up to 28% of the population
What rib-related changes may accompany dorsalization of L1
Elongated bones shaped like ribs may appear
What is the incidence of lumbar ribs in the population
7%
What is the gender bias associated with dorsalization of L1
Males are 2x-3x more affected
What alteration in C7 facet orientation may accompany dorsalization
The superior articular facet of C7 may change from BUM to that of a typical thoracic facet…BUL
The inferior articular facet is unchanged
What alteration in C6 facet orientation may accompany dorsalization
C6 demonstrates a change in inferior facet orientation from FOLD to ForMeD
The superior articular facet is unchanged
What is characteristic of sacralization of CO1
The premature fusion of Co1to the sacrum
What is the incidence of variation within the sacrococcygeal region in the population
Up to 14%
Which segment demonstrates the greatest morphological variation along the spine
L5
What is the incidence of sacralization of L5 in the population
41% - 85%
What is characteristic of sacralization of L5
L5 may be partially or completely fused to the sacrum
What T1 facet orientation changes may accompany cervicalization
The superior articular facet may change from BUL to BUM
The inferior articular facet is unchanged
What C7 facet orientation changes may accompany cervicalization
The inferior articular facet may change from ForMeD to FoLD
The superior articular facet is unchanged
What L1 facet orientation changes may accompany dorsalization
The superior articular facet may change from concave BUM to flat ForMeD
The inferior articular facet is unchanged
What T12 facet orientation changes may accompany dorsalization
The inferior articular facet may change from convex, FoLD to ForMeD and flat
The superior articular facet is unchanged
What rib-related changes may accompany lumbarization of T12
A significant shortening of the mean relative length of 113 mm of the 12th rib or it is absent
What T12 facet orientation changes may accompany lumbarization
The superior articular facet may change from BUL and flat to BUM and concave
The inferior articular facet is unchanged
What T11 facet orientation changes may accompany lumbarization
The inferior articular facet may change from ForMeD and flat to FoLD and convex
The superior articular facet is unchanged
What unique characteristics of lumbarization of S1 were STRESSED IN CLASS (TQ)
Squaring of the vertebral body of S1
Flaring of the sacral ala
