Exam 3: Transition Zones Flashcards
Name given to segments that lie in the transition zones of vertebral column
Transition vertebrae
What are the transition zones of vertebral column
Occipitocervical, cervicothoracic, thoracolumbar, lumbosacral, sacrococcygeal zones
How are specific segments within transition zone ID’ed
By adjacent region of the segment, process of transition, and specific segment (occipitalization of C1)
What does 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
Increase in occipital bone size, formation of new or larger lines on occipital bone
What 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
0.1% to 0.8%
When do centers of ossification for the odontoid process first appear
During last trimester in utero
When do bilateral ossification centers for odontoid process fuse
At or shortly after birth
What joint forms between odontoid process ossification centers and centrum of C2
Subdental synchondrosis
What joint classification present between C2 odontoid process and centrum
Amphiarthrosis synchondrosis
Ossification between odontoid process and centrum joint of C2 first appears at age
4
A joint between the odontoid process and centrum joint of C2 last ID’ed at
Age 7
What is name given to condition in which joint formed between odontoid process and centrum of C2 persists beyond age 7
Os odontoideum
What is os odontoideum
Persistence beyond age 7 of the joint formed between centrum and odontoid process centers of ossification
What is the name given to joint between odontoid process and centrum of C2 which is still evident beyond age 7
Persistent subdental synchondrosis
What is the name given to joint formed between tip of the dens and odontoid process centers of ossification
Tip of the dens synchondrosis
Classification of joint formed between tip of the dens and odontoid process centers of ossification
Amphiarthrosis synchondrosis
At what age will tip of dens center of ossification appear
Sometime in early adolescence
Based on age of appearance, how is tip of dens center of ossification classified
Secondary center of ossification
What age will tip of dens fuse with odontoid process
Before age 12
If joint formed between tip of dens and odontoid process centers of ossification persists beyond age 12, what is condition called
Terminal ossicle
What is a basilar impression
Persistence of nonunion of the basilar and condylar parts of chondrocranium such that the cartilage deforms due to the weight of the brain
What is a basilar invagination
Upper cervical spine appears to be invaginated into the skull on x-ray analysis
What is/are characteristics of dorsalization of C7
Addition of rib and changes in SAF orientation typical
Incidence of rib-related changes following dorsalization of C7
.5-2.5% of population
Do patients typically present with symptoms specific for dorsalization of C7
No
Typically asymptomatic
What is gender bias suggested in dorsalization of C7
Female
What alteration of C7 facet orientation may accompany dorsalization
SAF of C7 may change from BUM to BUL
IAF unchanged
What alteration in C6 facet orientation may accompany dorsalization
C6 demonstrates change in IAF from FoLD to ForMeD
SAF unchanged
What percent of 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 from fusion of a short rib to the T1 transverse process
Transverse foramen
What T1 facet orientation changes may accompany cervicalization
SAF may change from BUL to BUM
IAF unchanged
What C7 facet orientation changes may accompany cervicalization
IAF may change from ForMeD to FoLD
SAF is unchanged
Incidence of cervicalization of T1 in population
Up to 28%
What rib-related changes may accompany dorsalization of L1
Elongated bones shaped like ribs may appear
What is incidence of lumbar ribs in population
Over 7% demonstrates lumbar ribs
What L1 facet orientation changes may accompany dorsalization
SAF may change from BUM concave to flat, back, upward, lateral
IAF unchanged
What T12 facet orientation changes may accompany dorsalization
IAF may change from convex FoLD to flat, forward, medial, and downward
SAF unchanged
What gender bias associated with dorsalization of L1
Males 2-3X more affected
What rib related changes may accompany lumbarization of T12
Significant shortening of mean real active length of 113 mm of 12 rib or it becomes absent
What T12 facet orientation changes may accompany lumbarization
SAF from flat, back, upward, lateral to concave, back, upward, and medial
SAF unchanged
What T11 facet orientation changes may accompany lumbarization
IAF from flat ForMeD to convex FOLD
Usually way of ID’ing number of cervicals, thoracics and lumbar vertebrae during imaging studies
ID vertebra with ribs- these are thoracics , those higher are cervicals, those lower are lumbars
Characteristic of lumbarization of S1
Failure of synostosis between S1 and S2, squaring of vertebral body of S1 and flaring of sacral ala
Unique feature of lumbarization of S1 stressed in class
Squaring of vertebral body of S1 and flaring of sacral ala
What is failure of synostosis between S1 and S2
Segments do not completely fuse together
What is squaring of vertebral body of S1
S1 vertebral body has similar anterior and posterior heights, lack of wedging
What is flaring of sacral ala
Transverse process of ala appears to elevate as though separating from the rest of the sacral ala
What articular facet changes accompany lumbarization of S1
None
Characteristic of sacralization of L5
L5 may be partially or completely fused to sacrum
Incidence of sacralization of L5 in population
41-85%
Which segment demonstrates greatest morphological variation along spine
L5
What articular facet changes accompany sacralization of L5
None
Incidence of variation within sacrococcygeal region in population
Up to 14%
Characteristic of sacralization of Co1
Premature fusion of Co1 to sacrum
Characteristic of coccygealization of S5
Separation of S5 from sacrum and its premature fusion to Co1
Muscles associated with 5 true layers of the back
1- trap and lat 2- rhomboids, lev scapula 3- serratus’s 4- erector spinae 5- transversospinalis
Which muscles attaching to spinous processes represent layer one of true back
Trap and lat
Which muscles attaching to spinous processes represent layer 2 of true back
Rhomboids
Which muscles attaching to transverse processes represent layer 2 of true back
Levator scapula
Trapezius is innervated by
Spinal accessory nerve
What forms spinal accessory nerve
C1-C5 cord levels contribute to spinal root of spinal accessory nerve
Lat dorsi innervated by
Thoracodorsal nerve
What forms thoracodorsal nerve
Ventral rami C6-C8
Which muscles of true back innervated by dorsal scapular nerve
Levator scapula
Rhomboids
What forms dorsal scapular nerve
Ventral ramus C5
Levator scapula innervated by
Dorsal scapular nerve (ventral ramus C5) and branches from C3, C4 ventral rami
Rhomboid major innervated by
Dorsal scapular nerve (ventral ramus C5) and branches from C4 ventral ramus
Rhomboid minor innervated by
Dorsal scapular nerve (ventral ramus C5) and branches from C4 ventral ramus
What muscles lie just beneath trap in the neck
Splenius capitis and Cervicis