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Flashcards in Transition Zones Deck (50):
1

What are the transition zones of the vertebral column?

Occipitocervical, cervicothoracic, thoracolumbar, lumbosacral, and sacrococcygeal zones

2

What are the possible transition zone - segment combinations?

Cervicalization of the 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 characteristic(s) 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(s) of occipitalization or 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?

0.1-0.8%

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 sub dental 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 IDed 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 dens synchondrosis

15

At what age will the tip of the dens center of ossification appear?

Sometime in early adolescence

16

Based on the age to appearance, how is the tip of the dens center of ossification classified?

Secondary center of ossification

17

At what age will the tip of the dens fuse with the odontoid process?

Before age 12

18

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

19

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 wight of the brain

20

What is basilar invagination?

The upper cervical spine appears to be invaginated into the skull on X-Ray analysis

21

What is/are the characteristic(s) of dorsalization of C7?

The addition of a rib and changes in superior articular facet orientation are typical

22

What is the incidence of rib-related changes following dorsalization of C7?

From 0.5-2.5% of the population

23

Do patients typically present with symptoms specific for dorsalization C7?

No, they are typically asymptomatic

24

What is the gender bias suggested in dorsalization of C7?

Female

25

What alteration in C7 facet orientation may accompany dorsalization?

The superior articular facet of C7 may change from back, upward, and medial to that of a typical thoracic facet... Back, upward, and lateral; the inferior articular facet is unchanged

26

What percent of the population may demonstrate thoracic-like features at C7?

Up to 46%

27

What rib-related changes may accompany cervicalization of T1?

The fist rib may decrease in mean relative length or become absent

28

What will result form fusion of a shot rib to the T1 TVP?

The transverse Foramen

29

What T1 facet orientation change may accompany cervicalization?

The superior articular facet may change form back, upward, and lateral to back, upward, and medial; the inferior articular facet is unchanged

30

What is the incidence of cervicalization of T1 in the population?

Up to 28% of the population

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

33

What L1 facet orientation changes may accompany dorsalization?

The superior articular facet may change form concave, back, upward, and medial to flat, upward, and lateral; the inferior articular facet is unchanged

34

What T12 facet orientation changes may accompany dorsalization?

The inferior articular facet may change form convex, forward, lateral and downward to flat, forward, medial, and downward; the superior articular facet is unchanged

35

What is the gender bias associated with dorsalization of L1?

Males are 2-3x more affected

36

What rib-related changes may accompany lumbarization of T12?

A significant shortening of the mean relative length of 113mm of the 12th rib or it becomes absent

37

What T12 facet orientation changes may accompany lumbarization?

The superior articular facet may change from flat, back upward, and lateral to concave, back, upward, and medial; the inferior articular facet is unchanged

38

What is the usual way of IDing the the number of cervicals, thoracics and lumbar ertebrae during imaging studies?

ID the vertebrae with ribs - they will be thoracics; those higher are cervicals, those lower are lumbars

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 failure of synostosis between S1 and S2?

The segments don't completely fuse together

41

What is characteristic of sacralization of L5?

L5 may be partially or completely fuse to the sacrum

42

What is the incidence of sacralization of L5 in the population?

41-85%

43

Which segment demonstrates the greatest morphological variation along the spine?

L5

44

What is the incidence of variation within the sacrococcygeal region in the population?

Up to 14%

45

What is the characteristic of sacralization of Co1?

The premature fusion of Co1 to the Sacrum

46

What alteration in C6 facet orientation may accompany dorsalization?

C6 demonstrates a change in inferior articular facet orientation from forward, lateral, and downward to forward, medial, and downward; the superior articular facet unchanged

47

What C7 facet orientation changes may accompany cericalization?

The inferior articular facet may change from forward, medial, and downward to forward, lateral, and downward; the superior articular facet is unchanged

48

What T11 facet orientation changes may accompany lumbarization?

The inferior articular facet may change from flat, forward, medial, and downward to convex, forward, lateral, and downward; the superior articular facet is unchanged

49

What is squaring of the vertebral body of S1?

The S1 vertebral body has similar anterior and posterior heights, hence a lack of wedging

50

What is flaring of the sacral ala?

The TVP of the ala appears to elevate as though separating form the rest of the sacral ala