What Causes Scoliosis?

In 80 to 85 percent of people, the cause of scoliosis is
unknown; this is called idiopathic scoliosis. Before
concluding that a person has idiopathic scoliosis, the
doctor looks for other possible causes, such as injury
or infection. Causes of curves are classified as either
nonstructural or structural.
Scoliosis in Children and Adolescents
3•     Nonstructural (functional) scoliosis – A
structurally normal spine that appears curved. This
is a temporary, changing curve. It is caused by an
underlying condition such as a difference in leg
length, muscle spasms, or inflammatory conditions
such as appendicitis. Doctors treat this type of
scoliosis by correcting the underlying problem.
•     Structural scoliosis – A fixed curve that doctors
treat case by case. Sometimes structural scoliosis is
one part of a syndrome or disease, such as Marfan
syndrome, an inherited connective tissue disorder.
In other cases, it occurs by itself. Structural scoliosis
can be caused by neuromuscular diseases (such as
cerebral palsy, poliomyelitis, or muscular dystrophy),
birth defects (such as hemivertebra, in which one
side of a vertebra fails to form normally before
birth), injury, certain infections, tumors (such as
those caused by neurofibromatosis, a birth defect
sometimes associated with benign tumors on the
spinal column), metabolic diseases, connective tissue
dis orders, rheumatic diseases, or unknown factors
(idiopathic scoliosis).