Transition Zone Characteristics Flashcards
(42 cards)
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
