Alterations in normal spinal alignment that occur in the anteroposterior plane are termed scoliosis. Most scoliotic deformities are idiopathic. Scoliosis may also be congenital, neuromuscular, or compensatory from a leg-length discrepancy.
Etiology and Epidemiology
Idiopathic scoliosis is the most common form of scoliosis. It occurs in healthy, neurologically normal children. Approximately 20% of patients have a positive family history. The incidence is slightly higher in girls than boys, and the condition is more likely to progress and require treatment in females. There is some evidence that progressive scoliosis may have a genetic component as well.
Idiopathic scoliosis can be classified in three categories: infantile (birth to 3 years), juvenile (4-10 years), and adolescent (>11 years). Idiopathic adolescent scoliosis is the most common cause (80%) of spinal deformity. The right thoracic curve is the most common pattern. Juvenile scoliosis is uncommon, but may be under-represented because many patients do not seek treatment until they are adolescents. In any patient younger than 11 years of age, there is a greater likelihood that their scoliosis is not idiopathic. The prevalence of an intraspinal abnormality in a child with congenital scoliosis is approximately 40%.
Idiopathic scoliosis is a painless disorder 70% of the time. A patient with pain requires a careful evaluation. Any patient presenting with a left-sided curve has a high incidence of intraspinal pathology (syrinx or tumor). Evaluation of the spine with magnetic resonance imaging (MRI) is indicated in these cases.
Treatment of idiopathic scoliosis is based on the skeletal maturity of the patient, the size of the curve, and whether the spinal curvature is progressive or nonprogressive. Initial treatment for scoliosis is likely observation and repeat radiographs to assess for progression. No treatment is indicated for nonprogressive deformities. The risk factors for curve progression include gender, curve location, and curve magnitude. Girls are five times more likely to progress than boys. Younger patients are more likely to progress than older patients.
Typically curves under 25 degrees are observed. Progressive curves between 20 and 50 degrees in a skeletally immature patient are treated with bracing. A radiograph in the orthotic is important to evaluate correction. Curves greater than 50 degrees usually require surgical intervention.