Flashcards in Transition Zones Deck (59)
What is the name given to segments that lie in the transition zones of the vertebral column?
What are the transition zones of the vertebral column?
How are specific segments within a transition zone identified?
- by adjacent region of the segment
- process of transition
- specific segment (occipitalization of C1)
What does the suffix "ization" refer to?
in the process of becoming like
What are the possible transition zone-segmental combinations?
- cervicalization of occiput, occipitalization of C1
- dorsalization of C7, cervicalization of T1
- lumbarization of T12, dorsalization of L1
- sacralization of L5, lumbarization of S1
- coccygealization of S5, sacralization of Co1
What are the characteristics of cervicalization of occiput?
- an increase in occipital bone size
- formation of new or larger lines on the occipital bone
What is the characteristic of occipitalization of C1?
the atlas may be partially or completely fused to the occiput
What is another way of implying occipitalization of C1?
What is the incidence of occipitalization of C1?
When do the centers of ossification for the odontoid process first appear?
during the last trimester in utero
When do the bilateral ossification centers fr the odontoid process fuse?
at or shortly after birth
What joint is formed between the odontoid process ossification centers and the centrum of C2?
the subdental synchondrosis
What is the classification of the joint formed between the C2 odontoid process and centrum?
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?
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?
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 12, what is the condition called?
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 are the charactersistics of dorsalization of C7?
- addition of a rib
- changes in superior articular facet orientation
What is the incidence of rib-related changes following dorsalization of C7?
0.5-2.5% of the population
What genetic patterns are suggested in dorsalization of C7?
- chromosome karyotypes are abnormal
- family inheritance patterns are common
- it is associated with a dominant inheritance pattern
Do patients typically present with symptoms specific for dorsalization of C7?
no, they are typically asymptomatic