spinal trauma Flashcards
what is a good O-C1 interval between condyle and superior facet of C1
5mm
when does arch of C1 fuse
24 months
stability of os odontoidium
it is unstable
what is treatment of a hangmans fracture
if greater than 3 mm then minerva or halo rarely need fusion unless ligament injury
how is dens basion distance measured
between tip of odontoid and the basion in saggital plane- 10-12,mm in kids-5 in adults
basion axial interval is measured by
distance between the basion and the dorsal cortex of the odontoid- usually 12mm to PAL
how is powers measured and what is normal
BC/OA- basion to C1 line over the opistion to atlas line- notmal ratio 0.77 all over 1 abnormal
Lee line what is measured
like powers but extented down to C2- basion (B) to the midpoint of
the C2 spinolaminar line (C2SL)
posteroinferior
body of C2 to the opisthion (O)-
The
result is an X in which the basion-to-C2SL line should tangentially
intersect the posterosuperior dens and the C2-toopisthion
line should tangentially intersect the highest point
on the C1 spinolaminar line.- at least one intersection should be present
C1-2 and C2-3 interspinous ratio
- greater than 2.5 suggest damage to tectoral membrane
what is a normal adi and what does it measure
instability betoween C1-C2- in child less than 8 normal is <5 olter
halo pressure for kids
From ages 2 to 6, the number of pins can be
reduced to 8, starting with 2 inch-pounds of torque for a 2-
year-old with an increase of 1 inch-pound per year up to age 6.
Past this age, 4 pins may be used and should be tightened to 8
inch-pounds of torque, as in adult patients. Although they are
necessary to prevent iatrogenic skull fracture, a disadvantage of
using more pins in younger children is that there are fewer unused
holes on the ring to allow pin changes in cases of infection
or loosening at the pin site. Pins may loosen by up to 4 inchpounds
of torque within the first day after insertion or after
halo vest uprights are attached.
