In the last blog post we discussed the Risser sign, a
classic method to estimate bone age to predict the amount spinal growth
remaining in adolescents with scoliosis.
As you see from the last diagram in that post, the Risser sign doesn’t
show up until AFTER the peak height velocity.
So why does this matter?
The faster the spine grows, the greater the risk of
significant progression of the scoliosis.
The fastest time of spine growth is in the first 3 years of life
(see below diagram, area in light red).
But the second fastest time of spine growth is during the
pubertal growth phase (see below, area in light green box), and is one we call
the “Peak Height Velocity”.
Using the graph above, spine growth is fairly constant
between 6 and 11 years of age. It is
helpful to know before the growth acceleration occurs so we can have discussions
with families about the risk of progression and the need for various types of
treatment. Bracing is a commonly used
technique, but it works better in smaller, more flexible curves and it mainly
tries to prevent progression, not improve the deformity. If you want prevent curve progression, then
bracing needs to be started prior to the pubertal growth spurt.
As you see below, the Sanders Maturity Scale has three more
stages than Risser, and all of them are earlier making estimation of risk more
precise.
If we extrapolate the lines (below) you can better
appreciate how the Sanders Maturity Scale helps identify spine growth earlier
than the Risser sign
To assess the Sanders Maturity Scale the hand is used, so a
single hand radiograph/x-ray needs to be obtained. It doesn’t matter which hand.
If we order a hand radiograph/x-ray it’s because we want to
get a better idea of the person’s bone age so we can have more precise
discussions about progression risks and treatment.