Anatomical Variation

Question 1

Ocipitalisation of the atlas as failure of segmentation and different classification depending on areas fused

Answer 1

Tatara et al., (2016)

Question 2

Atlantoaxial subluxation has a 15-20% occurrence with Downs syndrome

Answer 2

Hatzantonis et al., (2016)

Question 3

Odontoid dysgenesis

Answer 3

Pang and Thompson, (2011)

Question 4

Psuedosubluxation of C2 as the anterior sliding of C2 on C3 commonly seen in the juvenile skeleton due to relatively large head, incomplete osssification of the odontoid
No implications in the juvenile skeleton

Answer 4

Kim, (2013)

Question 5

C2-3 segment the most commonly fused in Klippel-Feil syndrome

Answer 5

Cho et al., (2014)

Question 6

Occipitalization of the atlas affects boys and girls equally

Associated with abnormalities that lead to narrowing of space for brainstem

Answer 6

Gholve et al., (2007)

Question 7

57% of occipitalization patients had associated atlantoaxial instability
Numerous pts had associated Klippel-Feil VATER or 22q11 deletion

Answer 7

Gholve et al., (2007)

Question 8

Hemivertebrae are most common cause of congenital scoliosis and may be associated with a range of structural abnormalities
Different types/ classification

Answer 8

Johal et al., (2016)

Question 9

Hemivertebrae can be seen pre-natally on US and warrant surgery to remove them to prevent scoliosis
Controversial over when should intervene

Answer 9

Johal et al., (2016)

Question 10

Lumbarisation as a lumbosacral transitional vertebra affecting the first sacral vertebra and showing transition to a lumbar vertebra
And vice versa for sacralisation

Answer 10

Nakajima et al., (2014)

Question 11

Lumbarisation present at 6.2%
Lumbar ribs significantly associated with lumbarisation
All can cause miscounting of the lumbar vertebrae and affect surgery
Other studies do not take into account presence of other transitional anomalies such as lumbar ribs

Answer 11

Nakajima et al., (2014)

Question 12

Arcuate foramen is an ossification of the oblique atlanto-occipital ligament

Answer 12

Kim et al., (2015)

Question 13

Arcuate foramen leads to susceptibility to VA dissection as so much rotation occurs at AA joint makes the VA vulnerable to compression and stretching

Answer 13

Kim et al., (2015)

Question 14

Spectrum of VATER association

Answer 14

Botto et al., (1997)