Flashcards in TRANSITION ZONES OF THE VERTEBRAL COLUMN - Transition zone characteristics Deck (46):
1
What are the transition zones of the vertebral column?
occipitocervical, cervicothoracic, thoracolumbar, lumbosacral, and sacrococcygeal zones
2
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
3
What is/are the characteristics of cervicalization of occiput?
an increase in occipital bone size, formation of new or larger lines, on the occipital bone
4
What is/are the characteristics of occipitalization of C1?
the atlas may be partially or completely fused to the occiput
5
What is another way of implying occipitalization of C1?
atlas assimilation
6
What is the incidence of occipitalization of C1?
0.1% to 0.8%
7
When do the centers of ossification for the odontoid process first appear?
during the last trimester in utero
8
When do the bilateral ossification centers for the odontoid process fuse?
at or shortly after birth
9
What joint forms between the odontoid process ossification centers and the centrum of C2?
the subdental synchondrosis
10
Ossification between the odontoid process and centrum joint of C2 first appears at what age?
4 years old
11
A joint between the odontoid process and centrum of C2 is last identified at what age?
7 years old
12
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
13
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
14
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
15
At what age will the tip of the dens center of ossification appear?
sometime in early adolescence
16
At what age will the tip of the dens fuse with the odontoid process?
before age 12
17
What is the terminal ossicle?
a persistence beyond age 12 of the joint formed between the tip of the dens and odontoid process centers of ossification
18
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
19
What is a basilar invagination?
the upper cervical spine appears to be invaginated into the skull on x-ray analysis
20
What is/are the characteristics of dorsalization of C7?
the addition of a rib and changes in superior articular facet orientation are typical
21
What is the incidence of rib-related changes following dorsalization of C7?
from one-half to two and one-half percent of the population
22
What is the gender bias suggested in dorsalization of C7?
female
23
What alteration in C7 facet orientation may accompany dorsalization?
the superior articular facet of C7 may change from back, upward, and medial (BUM) to that of a typical thoracic facet...back, upward, and lateral (BUL); the inferior articular facet is unchanged
24
What alteration in C6 facet orientation may accompany dorsalization?
C6 demonstrates a change in inferior articular facet orientation from forward, lateral, and downward (FoLD) to forward, medial, and downward (ForMeD) ; the superior articular facet is unchanged
25
What percent of the population may demonstrate thoracic-like features at C7?
up to 46%
26
What rib-related changes may accompany cervicalization of T1?
the first rib may decrease in mean relative length or become absent
27
What will result from fusion of a short rib to the T1 transverse process
the transverse foramen
28
What T1 facet orientation changes may accompany cervicalization?
the superior articular facet may change from back, upward, and lateral (BUL) to back, upward, and medial (BUM) ; the inferior articular facet is unchanged
29
What C7 facet orientation changes may accompany cervicalization?
the inferior articular facet may change from forward, medial, and downward (ForMeD) to forward, lateral, and downward (FoLD) ; the superior articular facet is unchanged
30
What is the incidence of cervicalization of Tq in the population?
up to 28%
31
What rib-related changes may accompany dorsalization of L1?
elongated bones shaped like ribs may appear
32
What is the incidence of lumbar ribs in the population?
over 7% of the population demonstrates lumbar ribs
33
What L1 facet orientation changes may accompany dorsalization?
the superior articular facet may change from concave, back, upward, and medial (BUM) to flat, back, upward, and lateral (BUL); the inferior articular facet is unchanged
34
What T12 facet orientation changes may accompany dorsalization?
the inferior articular facet may change from convex, forward, lateral, and downward (FoLD) to flat, forward, medial, and downward (ForMeD) ; the superior articular facet is unchanged
35
What is the gender bias associated with dorsalization of L1?
males are two to three times more affected
36
What rib-related changes may accompany lumbarization of T12?
a significant shortening of the mean relative length of 113mm of the twelfth rib or it becomes absent
37
What T12 facet orientation may accompany lumbarization?
the superior articular facet may change from flat, back, upward, and lateral (BUL) to concave, back, upward, and medial (BUM) ; the inferior articular facet is unchanged
38
What T11 facet orientation changes may accompany lumbarization?
the inferior articular facet may change from flat, forward, medial, and downward (ForMeD) to convex, forward, lateral, and downard (FoLD) ; the superior articular facet is unchanged
39
What unique characteristics of lumbarization of S1 were stressed in class?
squaring of the vertebral body of S1 and flaring of the sacral ala
40
What is squaring of the vertebral body of S1?
the S1 vertebral body has similar anterior and posterior heights, hence a lack of wedging
41
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
42
What is characteristic of sacralization of L5?
L5 may be partially or completely fused to the sacrum
43
What is the incidence of sacralization of L5 in the population?
41% to 85%
44
Which segment demonstrates the greatest morphological variation along the spine?
L5
45
What is the incidence of variation within the sacrococcygeal region in the population?
up to 14%
46