Congenital Anomalies 1 Flashcards
What term is used for the underdevelopment of anatomy?
Hypoplasia
What term is used for the overdevelopment of anatomy?
Hyperplasia
What term is used for the absence of development of anatomy?
Aplasia
What term is used for the increased size of anatomy due to pathology?
Hypertrophy
What term is used for the increased size of anatomy from development?
Hyperplasia
What type of ossification occurs from a cartilage model formed from mesenchyme? Examples?
Enchondral ossification (extremities, spine, base of skull)
What type of ossification occurs when bone tissue replaces membranous fibrous tissue? Example?
Intramembranous ossification (skull)
What are the primary ossification centers of a vertebra?
One for centrum, two for each neural arch (3 total)
When are primary ossification centers present? Secondary?
Primary = before birth Secondary = after birth
What is the difference between an epiphysis and apophysis?
Epiphysis = forms articular cartilage and gives length to bone Apophysis = attachment for ligaments and tendons
Is a trochanter is an example of an apophysis or epiphysis?
Apophysis
What is the condition of the failure of separation of the most cranial somites?
Occipitalization (assimilation of atlas)
50% of those with occipitalization of atlas also have vertebral fusion at what level?
C2/C3
Since the odontoid process is high with occipitalization, is basically impression common?
No
What other films must be done when occipitalization is seen on the lateral X-ray?
Flexion/extension (assess ADI)
What are the areas of compensation for agenesis of the posterior arch of C1?
1 enlarged spinous of C2
2 hypertrophy of anterior tubercle
What is the condition where the posterior arch of C1 never developed due to a defect in the cartilage template?
Agenesis posterior arch
What must be done next when agenesis posterior arch is seen?
Flexion/extension views to check transverse atlantal ligament and to see if C1 and C2 are fused
Why does the anterior tubercle become larger with agenesis posterior arch?
Stress is shifted anteriorly from behind
What is the condition of spina bifida at C1?
Non union of the posterior arch of C1
Why can we still adjust on the posterior arch of C1 if there is a non union?
“hole” is mostly likely made out of cartilage and sturdy
What normal finding would be absent on the lateral cervical film with a non union of the posterior arch of C1?
Spinolaminar line
What area will compensate by increasing in size following a non union of the posterior arch of C1?
Anterior tubercle
What is the most common reason for a terribly large ADI?
Rheumatoid arthritis
What is the term for a small piece of bone that grows separately but near the anterior tubercle of C1 that is well corticated?
Accessory ossicle
Chiari malformations tend to lead to anomalies specific to what organ system?
Renal
What is a Chiari malformation?
Herniation of the cerebellar tonsils
Herniation of the cerebellar tonsils less than how many millimeters is considered within normal limits?
3mm
Chiari malformation is associated with what kind of spinal curvature?
“wrong way” scoliosis (different from the right thoracic norm)
Which is more clinically significant of a serious pathology: right or left scoliotic curve?
Left curve
What is the term for a cystic cavity in the spinal cord that tends to develop following an Chiari malformation?
Syrinx/syringomyelia
If a left curvature is seen upon X-ray, what should be the next move?
Adults = MRI if neurological symptoms are present Children = always do MRI
What would the treatment be for syringomyelia?
Laminectomy to relieve cord pressure
What is the eponym for a posterior ponticle?
Kimmerly anomaly
What ligament is ossified to form the ponticulus posticus?
Atlanta-occipital ligament between posterior aspect of lateral mass and posterior arch
What structures are contained in the arcuate foramen?
Vertebral artery and first cervical nerve
What is a bony extension originating from the transverse process of C1 to the skull base?
Epitransverse process
What is a bony extension originating from the skull base to the transverse process area of C1?
Paracondylar process
What is the significance of an epitransverse or paracondylar process?
1 possible lateral head tilt
2 may affect adjusting technique
What is os terminale?
Failure of the UNION of the secondary center of ossification found at the TIP of the dens
What is os odontoideum?
Failure of FUSION of the odontoid with the body of C2
When in age is os terminale usually seen?
After the age of 12
How can you differentiate between os terminale and a fracture?
Smooth, white margins = os terminale
Which is associated with hypermobility: os terminale or os odontoideum?
Os odontoideum
Why is hypermobility associated with os odontoideum?
Dens isn’t there to restrict the transverse atlantal ligament
What other conditions are associated with os odontoideum?
1 Down’s syndrome
2 Klippel-Feil syndrome
How can we assess for atlanto-axial stability especially in cases like an os odontoideum?
Flexion/extension views
Most os odontoideum are a result of what prior condition?
Old un-united odontoid fracture
Are most old un-united odontoid fractures an os odontoideum?
No
What kinds of neurological symptoms can be present with an os odontoideum?
Cerebellar/gait issues, upper motor neuron findings like hyperreflexia
What are the most common areas for block vertebrae?
C5/C6
C2/C3
L4/L5
How can you tell a block vertebra from a fusion derived from infection?
Maintenance of vertebral body height with block vertebra
What is the term for the smooth, concave anterior vertebral body margins seen with block vertebra?
Wasp waist vertebra
How is the IVD affected by block vertebra?
Hypoplastic
What structures become visible on a lateral X-ray with block vertebra that are usually only seen on cervical obliques?
IVFs
What are the four diagnostic criteria for block vertebra?
1 wasp waist configuration
2 hypoplastic IVD
3 IVFs visible on lateral X-ray
4 posterior elements also fused
How can block vertebra change mobility?
Hypo at area of blocking, therefore hyper above and below the area
What is the term for congenital fusion? Fusion from pathology? Fusion from surgery?
Congenital = synostosis Pathology = ankylosis Surgery = arthrodesis
What condition involves multiple block anomalies in the cervical spine?
Klippel-Feil syndrome
Klippel-Feil syndrome is associated with anomalies of what organ system in 50% of cases?
Renal
What is the unique appearance of the neck associated with Klippel-Feil syndrome?
Short, webbed neck (pterygium colli)
How is the appearance of the hair different in those with Klippel-Feil syndrome?
Low hairline
What other conditions or abnormalities are associated with Klippel-Feil syndrome?
1 renal anomalies
2 deafness
3 spinal cord issues like chiari
4 Sprengel’s deformity
What is Sprengel’s deformity?
Failure of a scapula to descend (appears elevated)
Horseshoe kidney is seen in patients with what cervical spine anomaly?
Klippel-Feil syndrome
What structures appear massive in the cervical spine due to Klippel-Feil syndrome along with anterior body scalloping?
IVFs
What gender is more likely to have Sprengel’s deformity?
Females (usually unilateral)
What is the piece of bone that can run from the superomedial border of the scapula to the spinous processes, transverses, or laminae of C4-C7?
Omovertebral bone
Omovertebral bones are found in 35% of cases of what other underlying condition?
Sprengel’s deformity
A finding of an elongated transverse of C7 occurs when it extends beyond what structure?
Transverse of T1
What forms when elongated transverses of C7 join?
Cervical rib
Which gender is more likely to have cervical ribs?
Females
What is the significance of cervical ribs (although normally asymptomatic)?
Thoracic outlet syndrome (especially in older patients)
Cervical ribs can be palpated and confused with what other structure?
Enlarged lymph nodes
Why do cervical ribs have symptomatology more in older patients?
Drooped posture of shoulders
How do pedicles change in a segment exhibiting butterfly vertebra?
Become wider
How do the vertebrae above and below a segment exhibiting butterfly vertebra change to compensate?
Round into the curved space
What causes a butterfly vertebra?
Failure of fusion of lateral halves secondary to persistence of notochord tissue
In what areas of the spine are butterfly vertebrae most common?
Thoracics and lumbars
Can we adjust butterfly vertebrae?
YES (if no hypermobility persists)
How do pedicles differ in the lumbar spine?
Become wider as you descend
What are the only two conditions that can cause pedicle shadows of a segment above to be wider than the segment below?
1 burst fracture
2 butterfly vertebra
What type of segment forms when there is a lack of formation of one half of a vertebral body?
Hemivertebra
What type of curvature can be caused by hemivertebra?
Structural scoliosis (usually 2 or more on the same side)
Hemivertebrae are associated with what other congenital anomaly?
Block vertebra
Which progress more: segmented or nonsegmented hemivertebra?
Segmented
Why are extra ribs a potential complication from hemivertebrae?
Possible aberrant respiration
In what region of the spine are Schmorl nodes more common?
Thoracics and lumbars
What causes Schmorl nodes?
Nucleus pulposus herniates through vertebral end plates
Giant Schmorl nodes are associated with what conditions?
1 degenerative disc disease
2 vacuum phenomenon
3 elongation of vertebral bodies
What is the other term for juvenile discogenic disease involving multiple Schmorl nodes?
Scheuermann’s disease
What causes a limbus vertebra?
Herniation of the nucleus pulpous through secondary growth centers (appear as free fragment at margin of body)
Where in the spine are limbus vertebrae most common?
Lumbars
Why is it easy to differentiate a limbus vertebra in the lumbars from a vertebral body avulsion fracture?
Avulsion = less common (also history)
Limbus vertebrae are associated with what condition?
Scheuermann’s disease
Cupid’s bow contour is seen with what condition?
Nuclear impression (notochordal persistance)
On what X-ray film can Cupid’s bow contour be seen?
A-P
What serious compilation can arise from significant spina bifida?
Meningocele (protrusion of meninges)
What is the most common location for spina bifida occulta?
L5/S1
Should spina bifida occult be considered in radiographic pre-employment screening?
NO
