Initial radiographs should include a posteroanterior and lateral standing film of the entire spine. The iliac crests should be visible to help determine skeletal maturity. The degree of curvature is measured from the most tilted or end vertebra of the curve superiorly and inferiorly to determine the Cobb angle (Fig. 202-2). Newer imaging modalities such as slot scanning or EOS provide the ability to obtain accurate measurements with much lower radiation than radiographs.
Alterations in normal spinal alignment that occur in the anteroposterior plane are termed scoliosis. Most scoliotic deformities
Figure 202-2 Cobb method of scoliotic curve measurement.
Determine the end vertebrae of the curve: They are at the upper and lower limits of the curve and tilt most severely toward the concavity of the curve. Draw two perpendicular lines, one from the bottom of the lower body and one from the top of the upper body. Measure the angle formed. This is the accepted method of curve measurement according to the Scoliosis Research Society. Curves of 0° to 20° are mild; 20° to 40°, moderate; and greater than 40°, severe.
are idiopathic. Scoliosis may also be congenital, neuromuscular, or compensatory from a leg-length discrepancy.
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 to 10 years), and adolescent (>11 years). Idiopathic adolescent scoliosis isthe most common cause (80%) of spinal deformity. The rightthoracic curve is the most common pattern. Juvenile scoliosis is uncommon, but may be underrepresented becausemany patients do not seek treatment until they are adolescents. In any patient younger than 11 years of age, there is agreater likelihood that 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 withmagnetic resonance imaging (MRI) is indicated in these cases.
Treatment of idiopathic scoliosis is based on the skeletalmaturity 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 repeatradiographs to assess for progression. No treatment is indicated for nonprogressive deformities. The risk factors forcurve progression include gender, curve location, and curvemagnitude. Girls are five times more likely to progress thanboys. Younger patients are more likely to progress than olderpatients.
Typically, curves under 25° are observed. Progressive curves between 20° and 50° in a skeletally immature patient are treated with bracing. A radiograph in the orthotic is important to evaluate correction. Curves greater than 50° usually require surgical intervention.
Abnormalities of the vertebral formation during the first trimester may lead to structural deformities of the spine that are evident at birth or early childhood. Congenital scoliosis can be classified as follows (Fig. 202-3):Partial or complete failure of vertebral formation (wedge vertebra or hemivertebra)Partial or complete failure of segmentation (unsegmented bars)Mixed