Why is congenital scoliosis different than idiopathic, syndromic, neuromuscular?
As presented 2 blogs ago, congenital scoliosis is the group of spinal deformity in
children that is due to the vertebra being abnormally developed. The other three diagnostic categories usually have normal vertebra development, for the most part. So, in the other three the growth of the vertebra are also much more “normal” in their shape and have the normal growth centers on each vertebra.
What are the “growth centers”
The vertebra basically grow from birth to adulthood in 2
ways: 1) the height of the vertebra increases due to the presence of growth
plates on the top and bottom of each vertebra, and 2) the width increases by
appositional growth, meaning it gradually widens without a growth plate. This widening of the vertebra is the same as
in other bones of the body, such as the femur, tibia, etc…
https://core.ac.uk/download/pdf/33505427.pdf
It is important to know, the main problem with vertebra
which are abnormally shaped, as in congenital scoliosis, is their abnormal
growth vertically, not horizontally. Though the abnormally shaped vertebra do
cause some of the scoliosis, it is the abnormal vertical growth of those
vertebra causes the majority of the problem, creating potentially severe,
progressive scoliosis.
Severe congenital scoliosis in a 4 y/o male
So, why do the vertebra grow abnormally? Simply put, there are an uneven number of
growth plates (with varying levels of growth capacity) on one side of the spine
vs. the other. Over a segment of the
spine, if there are 2 growth centers on the left side, and 5 on the right side,
the spine will grow more on the right side than the left. The speed of the asymmetric growth varies,
based on each growth plate present and other vertebra anatomy.
In the figure below, there is a partially formed vertebra
which is wedge shaped.
Now each disc, the area in blue means that there are 2
growth centers in the vertebra, one on each side of the disc, top and
bottom. This means on the left side
there are 4 discs and on the right side 3 discs. If each disc means there are 8 growth centers
on the left and 6 on the right. Hence,
there will be more growth potential on the left than the right.
In the next example, there is a bony bar across multiple
vertebra on the right side.
Using the disc concept we just talked about, there are 4
discs on the left, and one on the right.
This means 8 growth centers on the left and only 2 on the right.
More on congenital scoliosis next week….be safe