Congenital Anomalies/Variants Flashcards
Arcuate foramen forms when atlanto-occipital ligament calcifies. Transmits the sub-occipital nerve and the vertebral artery.
Posterior Ponticle
aka Posticus Ponticus
20% are born without the transverse ligament. Increased ADI indicates atlantoaxial instability. Must perform stress films before treatment is commenced.
Down’s Syndrome
Normally developed cephalic part of the dens is not fused with the C2 body. Smooth, wide, lucent defect between the body of C2 and dens.
Os Odontoideum
Adjacent vertebra osseously fused from birth. Associated with wasp waist and hypoplastic disc.
Congenital Block
Patient presents with a short webbed neck, low hair line, and decreased ROM. Multiple congenital blocks. Associated with Sprengle’s Deformity and omovertebral bone.
Klippel-Feil Syndrome
Contralateral pedicle hypertrophy and sclerosis
Pedical Agenesis
Failure of the center of the vertebral body to ossify properly
Butterfly Vertebra
Failure of development of a lateral ossification center. Isolated wedged vertebra causes a scoliosis. Associated with gibbus deformity
Hemivertebrae
Failure of the lamina to fuse. Elevated alpha fetoprotein and folic acid deficiency.
Spina Bifida
L5 TVP’s may fuse or form joints with the sacrum
Sacralization - Transitional segment
6 Lumbars (1st sacral segment appears like a lumbar segment)
Lumbarization - Transitional segment
Asymmetric articular planes. MC at L5/S1
Facet Trophism
Spina Bifida of S1 with L5 spinous enlargement. Pain on extension.
Knife Clasp Syndrome
Less than 120 degrees (normal coxa-femoral angle is 120-130 degrees)
Mikuliez’s line of mensuration
Coxa Vara
Greater than 130 degrees (normal coxa-femoral angle is 120-130 degrees)
Mikuliez’s line of mensuration
Coxa Valga
