Scoliosis
Scoliosis
is not a disease - it is a descriptive term. All spines have curves.
Some curvature in the neck, upper trunk and lower trunk is normal.
Humans need these spinal curves to help the upper body maintain proper
balance and alignment over the pelvis. However, when there are abnormal
side-to-side (lateral) curves in the spinal column, we refer to this
as scoliosis.
Congenital scoliosis is defined as a curvature of the spine that is
the result of malformations of the vertebral elements. The fact that
the spine and spinal column ever form correctly is amazing given the
complexity of the process from the embryological standpoint. Most of
this development happens during the 3rd-6th week in utero (after conception).
In spite of the opportunities for error, congenital malformations are
relatively rare.
Doctors think about
congenital scoliosis in three groups: failures of formation, failures
of segmentation, and combinations of these defects. The most common
failure of formation is called a hemivertebra. Hemivertebra produce
a growth imbalance in the spine and therefore result the spine growing
crooked. Failures of segmentation include block vertebra and unilateral
bars, which produce a growth tether of the spine. Finally, when these
occur in combination, such as a hemivertebra on one side and a bar on
the other, the scoliosis can progress in very rapid manner.
Idiopathic scoliosis is the most common form of scoliosis in North America,
affecting up to 2 % of the population. It's usually caused by an adolescent
growth spurt. In order for a physician to diagnose and treat idiopathic
scoliosis, he or she must first rule out all other causes of scoliosis.
Most idiopathic curves present in adolescence are painless, gradual,
have a typical curve pattern (for example, a right thoracic curve),
and the neurological exam is normal. Idiopathic scoliosis is much more
common in females.
Kyphosis or hunching over is normal in the thoracic spine. If you look
at your child from the side, you will notice that there is a curve in
the upper back where they are "hunched over", and a curve in the lower
spine ("sway back"). Some kyphosis is normal.
When the doctor measures it on an x-ray, the normal range for kyphosis
is quite broad, between 20-50 degrees. However, when kyphosis is greater
than 50 degrees, it becomes easy to see and is considered abnormal.
Most parents will attribute this to "poor posture", but become concerned
that despite their persistent reminders, their child will not stand
up straight.
There are two common
forms of kyphosis encountered in the teenage population: Scheueremann's
kyphosis and Postural Roundback. Scheueremann's kyphosis is most common
in teenage boys. It is characterized by a short, sharp kyphosis in the
middle part of the upper spine, and may be associated with aching back
pain. The kyphosis tends to be rigid on clinical examination. There
are x-ray criteria that establish a diagnosis of Scheueremann's kyphosis
that can be seen on the x-ray. A mild degree of scoliosis is common
in adolescents with Scheueremann's kyphosis.
Postural Roundback
is noted by a smooth, flexible kyphosis that is not typically associated
with pain. The curve is easily corrected by asking the child to stand
up straight. Radiographically, the criteria for the diagnosis of postural
roundback are kyphosis greater than 50 degrees, but without the other
x-ray findings seen with Scheueremann's kyphosis. These curves tend
to be mild in severity and extend over a longer number of vertebral
segments when compared to Scheueremann's kyphosis.
The term "neuromuscular scoliosis" is used to describe curvature of
the spine in children with any disorder of the neurological system.
Common categories include cerebral palsy, spina bifida, muscular dystrophies,
spinal cord injuries and so forth. Most of these children have as a
unifying feature weakness of the trunk. As they grow and their trunk
gets weaker, there is a progressive, collapsing deformity of the spine
producing a long, c-type curve. These curves tend to be progressive,
with the rate of progression becoming worse during rapid growth. For
children confined to a wheel chair, progressive curves may affect the
child's ability to be seated comfortably, thereby affecting their quality
of life and function.