Transition Zones Flashcards Preview

Spinal Anatomy > Transition Zones > Flashcards

Flashcards in Transition Zones Deck (40):
1

What is/are the characteristic of occipitalization of C1?

Atlas may be partially or completely fused to the occiput

2

What is another way of implying occipitalization of C1?

Atlas assimilation

3

What is the incidence of occipitalization of C1?

0.1% to 0.8%

4

When do the centers of ossification for the odontoid process first appear?

During last trimester in utero

5

When do the bilateral ossification centers for the odontoid process fuse?

At or shortly before birth

6

What joint is formed between the odontoid process ossification centers and the centrum of C2?

Subdental synchondrosis

7

What is the classification of the joint formed between the C2 odontoid process and centrum?

Amphiarthrosis synchondrosis

8

Ossification between the odontoid process and centrum joint of C2 first appears at what age?

4 years old

9

A joint between the odontoid process and centrum of C2 is last identified at what age?

7 years old

10

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

11

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

12

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

13

What is the classification of the joint formed between the tip of the dens and odontoid process centers of ossification?

Amphiarthrosis synchondrosis

14

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

Sometime in early adolescence

15

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

Secondary center of ossification

16

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

Before age 12

17

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

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?

Upper cervical spine appears to be invaginated into the skull on x-ray analysis

20

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

From 0.5% - 2.5% of the population

21

Do patients typically present with symptoms specific for dorsalization of C7?

No, they are typically asymptomatic

22

What is the gender bias suggested in dorsalization of C7?

Female

23

What alteration in C7 facet orientation may accompany dorsalization?

Superior articular facet of C7 may change from BUM to a typical thoracic of BUL
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 FoLD to ForMeD
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?

First rib may decrease in mean relative length or become absent

27

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

Up to 28% of the population

28

What is the incidence of lumbar ribs in the population?

Over 7% of the population demonstrates lumbar ribs

29

What T12 facet orientation changes may accompany dorsalization?

Inferior articular facet may change from convex FoLD to flat ForMeD
Superior articular facet is unchanged

30

What is the gender bias associated with dorsalization of L1?

Males are two to three times more affected

31

What rib-related changes may accompany lumbarization of T12?

Significant shortening of the mean relative length of 113mm of the twelfth rib or it becomes absent

32

What T11 facet orientation changes may accompany lumbarization?

Inferior articular facet may change from flat ForMeD to convex FoLD
Superior articular facet is unchanged

33

What is the unusual way of identifying the number of cervicals, thoracics and lumbar vertebrae during imaging studies?

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

34

What is characteristic of lumbarization of S1?

The failure of synostosis between S1 and S2
Squaring of the vertebral body of S1
Flaring of the sacral ala

35

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

41%-85%

36

Which segment demonstrates the greatest morphological variation along the spine?

L5

37

What articular facet changes accompany sacralization of L5?

None

38

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

Up to 14%

39

What is characteristic of sacralization of Co1?

Premature fusion of Co1 to the sacrum

40

What is characteristic of coccygealization of S5?

Separation of S5 from sacrum and its premature fusion to Co1