STOPP pediatric spine variants

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15 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

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STOPP pediatric spine variants
mimicking fractures


images for
pictorial review paper

(‘save as image’)

Figure 1


Developmental cleft mimicking fracture


6 month old boy transferred to tertiary
hospital after fall from bed, radiographs reported to show a vertebral fracture. (a)
frontal radiograph showing oblique
lucency

at posterior elements of L2 (arrow). (b
-
d) Axial, coronal and sagittal CT images in bone windows, demonstrating smooth,
sclerotic margins at an oblique developmental cleft.

Figure 2


Ring
apophyses
. (a) Ossification of ring
apophyses

in a
XX year old M/F

[06
-
57
-
NS
-
0
17JUN05


baseline scan]
. (b) Corresponding diagram of development of ring
apophyses

at endplate margins. (c) Ossification and fusion of ring
apophyses

over a four year period
in the same patient.

0

24 months

36 months

48 months

Figure 3


Genant

semi
-
quantitative grading system for vertebral compression fractures. In
this classification, maximal height loss in any part of the vertebra as a proportion
of the vertebral height measuring <25% is mild, 25
-
40% is moderate, and >40%
severe. [WILL NEED PERMISSION


Genant

1993, JBMR]

Figure 4


Normal progression from convex to concave endplates at T12 and L1 over four
years, in a M/F
first imaged at XX years
[07
-
306
-
NS
-
0]. Note also the ossification
and fusion of ring
apophyses

during this time, which contributes to the final
apparent concavity of endplates.

Baseline

3 years

4 years

Figure 5


(a) Exaggerated anterior wedging near 25% height loss in a mid thoracic vertebra (*),
in an XX
year old M/F [06
-
224
-
NS
-

36 months]
. This was present and unchanged on all scans for 3 years.
(b) Wedge compression fracture with near 25% anterior height loss at T11 (*)
in an XX year old
M/F [08
-
228
-
LK
-
0 36 months]
.

(c) Diagram distinguishing between these. In both
casesthe

endplates appear uninterrupted so that criterion is not helpful. Note that in the upper vertebra,
drawn from (a), the posterior portions of the endplates retain their normal childhood convexity,
while in the lower vertebra, drawn from (b), the endplates are flattened and linear. Also, (b)
shows a double endplate contour (bone
-
in
-
bone), which although nonspecific, can be seen
during fracture healing.


*

*

Physiologic

Fracture

Figure 6


Indentation for anterior ring
apophysis

vs. fracture. (a) Step deformities (*) at anterior superior
endplates of T12 and L1 in a
XX year old M/F

[
06
-
210
-
NS
-
0, 24
mo

film]
, representing prominent
notches at the as yet un
-
ossified anterior ring
apophysis
. A clue that this is a normal variant is the
preserved outward convexity of the endplates immediately posterior to this. The anterior cortex
should be stronger than the trabecular bone just posterior to it, so a fracture involving anterior
cortex ought to also depress the endplate posterior to it. (b) Typical appearance of a thoracic
compression fracture (*),
in a XX year old M/F [09
-
106
-
LK
-
0, 12
mo

film
]. Although there is some
anterior height loss, the most height loss is in the mid
-
vertebra, where little vertically oriented
cortical bone is available to protect from loading. The endplate is concave upward just posterior to
the anterior cortex, rather than convex as in (a). Note the normal convex
-
outward appearance of
the lower vertebra seen in (b).

06
-
210
-
NS
-
0, 24 months

09
-
106
-
LK
-
0, 12 months

*

*

*

*

*

Figure 7


Anterior vertebral wall


vascular groove vs. fracture. (a) Typical linear indentation
(arrows) at mid anterior vertebral body wall in a
XX year old M/F [03
-
344
-
RC
-
0, baseline]

representing a vertebral artery groove. This is unlikely to be confused for fracture. (b) An
XX year old M/F [08
-
44
-
LK
-
0, 24 month film]

with residual indentation (arrow) at anterior
vertebral body walls from ossifying vertebral artery grooves. (c) Anterior wedge
compression fracture
in an XX year old M/F
with linear flattening of endplates. The
indentation of anterior cortex is similar to (b) and may be incidental.
[07
-
24
-
LK
-
0, 24
months]

Figure 8


Anterior vertebral
beaking

at upper lumbar vertebrae in
mucopolysaccharidoses
,
for comparison with normal variation. (a) 5 year old boy with
Morquio

syndrome.
Typical central
beaking

most pronounced at L1 and L2 (arrows). (b) 4 year old boy
with Hurler’s syndrome.
Hypoplastic

anterior aspect of T12 with
gibbus

deformity
(arrow), and inferior
beaking

at L1 (arrowhead). (c) 4 year old boy with Hunter
syndrome.


Exaggerated convexity of vertebral body contours, which appear
rounded, with prominent impressions at un
-
ossified ring
apophyses

(arrow).


Developmental cleft mimicking fracture


6 month old boy transferred to tertiary
hospital after fall from bed, radiographs reported to show a vertebral fracture. (a)
frontal radiograph showing oblique
lucency

at posterior elements of L2. (b
-
d) Axial,
coronal and sagittal CT images in bone windows, demonstrating smooth, sclerotic
margins at an oblique developmental cleft.

Figure 9


Shorter posterior wall of L5 than anterior, giving trapezoidal vertebral body shape.
Although this does not represent a posterior crush fracture, this morphology has
an association with
spondylolisthesis
, as seen in this
XX year old M/F

with short
posterior L5 vertebral body wall, grade 1
anterolisthesis

of L5 on S1 and clearly
visible L5 pars defects (arrow)
[07
-
146
-
RC
-
0, 36 month]
.

Figure 10


Cupid’s bow vs. biconcave fracture. (a) Cupid’s bow or balloon disk at multiple
levels in
an XX year old M/F [03
-
174
-
RC
-
0, 48 months]
. This normal variant is a
curved indentation
centred

at the posterior third of the endplate (arrows). The
shape resembles Cupid’s bow (diagram, lower), and when present at adjacent
endplates, gives the impression of disk expansion, hence is also known as ‘balloon
disk’. (b) Biconcave endplate fracture at L5, in
an XX year old M/F [09
-
106
-
LK
-
0, 12
months]
. There is interruption of the superior endplate of L5, the endplate
concavities are centered at the mid disk rather than the posterior third, there is
overall height loss, and adjacent levels are not affected.

Figure 11


Parallax effect. (a) Image of upper lumbar spine in an
XX year old M/F [02
-
445
-
RC
-
0,
baseline]

shows non
-
overlapping endplates, especially at L2 (arrows), due to parallax. (b) A
follow
-
up image obtained 3 years later shows overlapping endplates without parallax effect.
(c) Diagram of parallax effect. The side of the object closest to the X
-
ray source is magnified
compared to the other side. For vertebrae, this gives an appearance of bone
-
in
-
bone, or
endplate interruption. This is minimized by using a source as far away as possible, and
centering the beam appropriately.

Object

Xray

source

Detector

Image

Figure 12


Normal variants involving irregular endplates. (a) Multiple
Schmorl

nodes near
thoracolumbar junction in a
XX year old M/F [02
-
258
-
RC
-
0, 24 month]
.

The
endplates are irregular with areas of focal depression and sclerosis implying sites
of
intraosseous

disk herniation. There is only minimal anterior wedging, not
meeting criteria for wedge compression fracture. (b)
Scheuermann’s

kyphosis in a
XX year old M/F [07
-
132
-
LK
-
0, 12 months]
. Endplate irregularity and mild anterior
wedging are seen at multiple mid
-
thoracic levels, resulting in increased kyphosis.

Figure 13


Diagram of several normal variants that may mimic fractures in pediatric thoracic
and lumbar vertebrae.

Non
-
ossified ring
apophysis

Schmorl

nodes

Anterior vertebral artery impression

Cupid’s bow

A

P

If A<P by <10%, may be physiologic wedging

If P<A at L5, ?
spondylolisthesis

Parallax