Unit 9 Transition zones of the vertebral column (final exam) Flashcards
What is the name given to segments that lie in the transition zones of the vertebral column?
Transition vertebrae
What are the transition zones of the vertebral column?
Occipitocervical Cervicothoracic Thoracolumbar Lumbosacral Sacrococcygeal
How are the specific segments within a transition zone identified?
By adjacent region of the segment, process of transition, and specific segment
What does the suffix “ization” refer to?
process of becoming like
What are the possible transition zone-segmental combinations?
Cervicalization of occipt, 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 is/are the characteristics of cervicalization of occiput?
Increase in occipital bone size
Formation of new or larger lines on occipital bone
What is/are the characteristics of occipitalization of C1?
Atlas may be partially or completely fused to occiput
What is another way of implying occipitalization of C1?
Atlas assimilation
What is the incidence of occipitalization of C1?
.1-.8%
When 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 forms between the odontoid process ossification centers and the centrum?
Subdental synchondrosis
What joint classification is present between the C2 odontoid process and 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
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 an os odontoideum?
persistence beyond age 7 of joint formed by 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 given to the joint formed between the tip of the dens and the odontoid process of centers of ossification?
tip of the dens synchondrosis
At what age will the tip of the dens center of ossification appear?
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 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?
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 is basilar invagination?
Upper cervical spine appears to be invaginated into the skull on xray analysis.
What is/are the characteristics of dorsalization of C7?
Addition of a rib
Changes in superior articular facet orientation are typical
What is the incidence of rib-related changes following dorsalization of C7?
.5-2.5% of the population
Do patients typically present with symptoms specific for dorsalization of C7?
No, Asymptomatic
What is the gender bias suggested in dorsalization of C7?
Female
What alteration in C7 facet orientation may accompany dorsalization?
superior is BUM–>BUL
Inferior is unchanged
What alteration in C6 facet orientation may accompany dorsalization?
Inferior is FoLD–> ForMeD
Superior is unchanged
What percent of the population may demonstrate thoracic-like features at C7?
up to 46%
What rib-related changes may accompany cervicalization of T1?
first rib may decrease in mean relative length or become absent
What will result form fusion of a short rib to the T1 TVP?
Transverse foramen
What T1 facet orientation changes may accompany cervicalization?
Superior is BUL—> BUM
Inferior is unchanged
What C7 facet orientation changes may accompany cervicalization?
inferior is ForMeD–>FoLD
Superior is unchanged
What is the incidence of cervicalization of T1 in the population?
up to 28%
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 L1 facet orientation changes may accompany dorsalization?
Superior is concave BUM—>BUL
Inferior is unchanged
What T12 facet orientation changes may accompany dorsalization?
Inferior is FoLD—>ForMeD
Superior is unchanged
What is the gender bias associated with dorsalization of L1?
Males 2-3x
What T12 facet orientation changes may accompany lumbarization?
Superior is flat, BUL—>concave BUM
Inferior is unchanged
What T11 facet orientation changes may accompany lumbarization?
Inferior is flat,ForMeD—> Convex, FoLD
Superior is unchanged
What is characteristic of lumbarization of S1?
Failure of synostosis between S1 and S2, squaring of the vertebral body of S1 and flaring of the sacral ala
What unique characteristics of lumbarization of S1 were stressed in class?
Squaring of the vertebral body of S1 and flaring of the sacral ala.
What is failure of synostosis between S1 and S2?
the segments do not completely fuse together.
What is flaring of the sacral ala?
the Transverse process of the ala appears to elevate as though separating from the rest of the sacral ala.
What articular facet changes accompany lumbarization of S1?
None
What is characteristic of sacralization of L5?
L5 may be partially or completely fused to the sacrum
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 variation within the sacrococcygeal region in the population?
Up to 14%
