Scoliosis is defined as a lateral curvature of the spine that is usually accompanied by rotation. Scoliosis is not a diagnosis, but a description of a structural alteration that occurs in a variety of conditions. Progression of the curvature during periods of rapid growth may result in significant deformity, which may be accompanied by cardiopulmonary compromise.

Terminology - Scoliosis is defined as curvature of the spine in the coronal plane. It is typically accompanied by a variable degree of rotation of the spinal column. By convention, 10º of curvature (as measured by the Cobb angle) defines a scoliosis. Curves with Cobb angle of less than 10º are referred to as spinal asymmetry and are of no long-term clinical significance. The direction (right or left) of a scoliotic curve is defined by curve's convexity. The location is defined by the vertebra that is most deviated and rotated from midline, called the apical vertebra.

Etiologic classification of scoliosis - There are three broad categories of scoliosis: neuromuscular, congenital, and idiopathic: Neuromuscular scoliosis occurs in patients with neurologic or musculoskeletal problems such as cerebral palsy, myelomeningocele, muscular dystrophy, or leg length discrepancy. It is the result of muscle imbalance and lack of trunk control. Neuromuscular scoliosis may be structural or nonstructural. Nonstructural scoliosis has no rotational component; it may be related to postural abnormalities, leg length discrepancy, or pain (eg, splinting in patients with pneumonia or empyema). Most patients with neuromuscular scoliosis have additional findings related to the underlying disorder that help in making the diagnosis.

Congenital scoliosis results from asymmetry in the vertebrae secondary to congenital anomalies (eg, hemivertebrae, failure of segmentation). Congenital scoliosis usually manifests before adolescence.

Idiopathic scoliosis is scoliosis for which there is no definite etiology; it is therefore a diagnosis of exclusion. Idiopathic scoliosis is divided into three subcategories based upon the patient's age at presentation:

      -  Infantile: 0 to 3 years
      -  Juvenile: 4 to 9 years
      -  Adolescent: 10 years
 

Infantile and juvenile idiopathic scoliosis are sometimes considered together and called "early-onset" idiopathic scoliosis; with this terminology, adolescent idiopathic scoliosis is called "late-onset" idiopathic scoliosis. Adolescent idiopathic scoliosis (AIS) is the most common form of idiopathic scoliosis, accounting for between 80 and 85 percent of cases.

The prevalence of AIS with a Cobb angle 10º is approximately 3 percent, but only 10 percent of adolescents with AIS require treatment (0.3 percent of the population). Males and females are affected equally. However, the risk of curve progression and therefore the need for treatment is 10 times higher in females than in males. The prevalence and female: male (F:M) ratio of AIS of varying degrees of severity is as follows: Cobb angle 10º: 2 to 3 percent, F:M 1.4 to 2.4:1 Cobb angle 20º: 0.3 to 0.5, F:M 5.4:1 Cobb angle 30º: 0.1 to 0.3, F:M 10:1 Cobb angle 40º: 0.1

The etiology of AIS is unclear. Twin studies have shown a much higher concordance in the incidence and degree of scoliosis in monozygotic than dizygotic twins, supporting a genetic contribution. The increased prevalence of scoliosis among individuals who have an affected sibling or parent provides additional support for the role of heritability. In one study, for example, the prevalence of scoliosis among first, second, and third degree relatives of 52 girls with AIS was 6.9, 3.7, and 1.6 percent, respectively. Another series evaluated the risk for subsequent siblings of index patients according to sex of the subsequent sibling and whether or not a parent was affected. If neither parent was affected, the risk for a subsequent sister was 7 percent and for a subsequent brother was 2 percent; if one parent was affected, the risk for a subsequent sister was 42 percent and for a subsequent brother was 7 percent. Genetic loci for AIS have been mapped to chromosomes 17 and 19, but the inheritance pattern is unclear. It may be explained by either a multifactorial model or a dominant major gene diallele model with incomplete sex- and age-dependent penetrance. The expression of familial AIS may be linked to the X chromosome, with a dominant inheritance pattern. Other factors that have been proposed (but not definitively proved) to have a role in the pathogenesis of AIS include: abnormalities in growth hormone secretion, connective tissue structure, paraspinal musculature, vestibular function (as it relates to axial posture), melatonin secretion (as it relates to growth), and platelet microstructure, since the contractile system of platelets is similar to that of skeletal muscle.

The studies describing the natural history of AIS have important limitations including incorporation of patients with nonidiopathic etiologies and/or early onset scoliosis, lack of radiographic data, loss of patients, and small numbers. Most of the patients included in these series were female and had thoracic curves. These limitations notwithstanding, these reports provide important observations regarding the natural history of untreated AIS.

The natural history of untreated AIS is one of stabilization or progression of the curve. Curves progress in approximately two-thirds of skeletally immature patients before they reach skeletal maturity. The magnitude of progression varies depending upon sex, curve magnitude at presentation, curve pattern, and remaining growth potential. In one review of 123 skeletally immature patients (mean age 14 years) with idiopathic scoliosis and Cobb angles less than 50º who were followed without treatment until skeletal maturity, the average curve measured 33º (range 10 to 49) at the time of diagnosis and 49º (range 12 to 97) at skeletal maturity. The curves remained unchanged (progressed by <5º) in 32 percent of patients and progressed by 5º in 68 percent, >10º in 34 percent, >20º in 18 percent, and >30º in only 8 percent.

Scoliosis can continue to progress after skeletal maturity in untreated patients, particularly in those with curves measuring >40º at the end of growth. Curves >50º generally progress one degree per year after skeletal maturity. Curves measuring 30º at the end of growth typically do not progress. In one long-term study, 133 untreated curves in 102 patients were followed for an average of 40.5 years after skeletal maturity. Two-thirds of the curves progressed, with an average rate of 0.75 to 1 degree per year. Factors related to progression after skeletal maturity included severity of curve at diagnosis (curves with Cobb angles >30º tended to progress, whereas smaller curves did not) and curve location (increased risk with thoracic curves). Most patients with AIS have little, if any, functional limitation or pain in adulthood. Back pain is slightly more common than in the general population, but is rarely disabling, and the risk of neuropathy is low. Mortality is not increased compared to the general population.

Adolescents with AIS may present in several ways. In some patients, scoliosis is noted as an incidental finding on physical examination. Others have complaints related to the deformity (eg, asymmetry of the shoulders, flank creases, hips, scapulae, or breasts). Some patients present because an abnormality was noted by the school nurse during scoliosis screening at school. Patients with severe thoracic curves (Cobb angle of 70º) may have restrictive pulmonary disease. However, such curves usually have onset before age 10 years (i.e., infantile or juvenile idiopathic scoliosis).

Evaluation of the adolescent with scoliosis has several objectives, including identification of an underlying etiology, assessment of the magnitude of the curve and need for radiographs, and determining the risk of progression, which influences management decisions.

History - Questions in the history are centered upon determining an underlying etiology and the risk for progression (based upon estimation of remaining potential for linear growth). Important aspects of the history include: When was the deformity first noted and who noted it? What is the rate of progression? Rapid progression of the curve is suggestive of nonidiopathic etiology? Is there associated pain? The presence of significant pain (pain that limits activities or requires frequent analgesia) increases the likelihood of nonidiopathic etiology. This was illustrated in a review of 2442 patients in which 23 percent complained of pain at the time of presentation; among these patients, 9 percent had an underlying pathologic condition (spondylolysis, spondylolisthesis, Scheurmann kyphosis, syrinx, herniated disc, hydromyelia, tethered cord, intraspinal tumor).

Patients with significant pain may require additional evaluation, particularly those who have neurologic symptoms or signs and/or a left thoracic curve. Are there associated symptoms suggestive of a neuromuscular etiology (eg, muscle weakness, bowel or bladder problems, headache, neck pain)? Neurologic symptoms increase the likelihood of nonidiopathic causes and require additional evaluation. Does the patient have shortness of breath or difficulty breathing? Severe thoracic scoliosis may affect pulmonary function. What is the patient's growth trajectory and has the pubertal growth spurt begun? This information helps to estimate remaining linear growth and need for intervention. Has the patient entered puberty? Tanner grade 2 (the onset of puberty) precedes the onset of the pubertal growth spurt in boys, but follows the onset of the pubertal growth spurt in girls. For female patients, has menarche occurred? If so, when? The pubertal growth spurt usually occurs just before menarche. Girls continue to grow at decreased velocity for approximately one year after menarche and complete linear growth by 24 months after menarche. Is there a history of lower limb fracture, joint infection, or arthritis (which may result in leg length discrepancy)? Is there a family history of scoliosis? AIS tends to run in families.

General examination - Important aspects of the general examination include: Measurement of the patient's height, which should be plotted on a growth curve standardized for age and sex. This helps to estimate the remaining growth potential. Linear growth is near completion when there has been <1 cm of change in standing height over a six month period. Assessment of Tanner stage. The risk for curve progression is greatest during the pubertal growth spurt, the onset of which precedes Tanner stage 2 in girls, and follows Tanner stage 2 in boys. Examination of the skin for café-au-lait spots and axillary freckling (suggestive of neurofibromatosis); vascular, hypopigmented, or hypopigmented lesions or a patch of hair overlying the spine (which may be associated with spinal dysraphism); and dimpling in the lumbosacral area (which may be associated with intraspinal tumor). Excessive skin or joint laxity may be associated with Ehlers-Danlos or Marfan syndrome. Asymmetry on bilateral palpation of the iliac crests and posterior inferior iliac spines with the patient in the standing position with the hips and knees fully extended suggests leg length discrepancy. If a leg length discrepancy is present, clinically apparent scoliosis may be compensatory. A compensatory scoliosis will usually correct when the leg lengths are evened out by placing a block under the shorter leg. If leg length discrepancy is a possibility, the patient's leg lengths should be measured. Leg length is measured with the patient supine and the legs extended and held together in the midline; the measurement is taken from the anterior superior iliac spine to the medial malleolus, with the tape running medial to the patella. The feet should be examined for high arches (pes cavus) and hammer or claw toes, which are suggestive of neuromuscular disease such as Friedreich ataxia. A full neurologic examination, including examination of the reflexes should be performed. Balance and strength of the lower extremities can be assessed by watching the patient walk normally, toe and heel walk, squat deeply, and hop on each leg. The abdominal reflex is especially important, since an absent abdominal reflex is sometimes indicative of subtle intraspinal pathology. Elicitation of the abdominal reflex involves lightly stroking the skin on one side of the upper, middle, and lower abdomen (above, at, and below the umbilicus, respectively); the normal response is contraction of the muscles, pulling the umbilicus and midline to the stimulated side.

Scoliosis examination - Examination for scoliosis is facilitated by proper exposure of the trunk (i.e., an examination gown that is open in the back, with undergarments that expose the iliac crests and posterior and anterior superior iliac spines).

Inspection - The first step in the scoliosis examination is simple inspection. Though minor curves may not be immediately obvious when viewing a standing patient from behind, subtle differences in the height of the shoulders or scapulae, waistline symmetry, and the distance arms hang from the trunk may be appreciated on closer inspection. The patient's head should appear "balanced" over the center of the sacrum and not shifted to one side or the other. Viewed from the side, the patient should have the normal profile of thoracic kyphosis and lumbar lordosis; decreased thoracic kyphosis may be seen. The majority (90 percent) of curves in AIS are right thoracic curves. Left thoracic curves have been associated with nonidiopathic causes and may require additional evaluation.

Forward bend test - The Adams forward bend test is performed by observing the patient from the back while he or she bends forward at the waist until the spine becomes parallel to the horizontal plane, with feet together, knees straight ahead, and arms hanging free. In a patient with scoliosis, a thoracic (rib) or lumbar (loin) prominence on one side will be evident. The Adams forward bend test actually demonstrates the rotational component of scoliosis, since the rib prominence is the result of the ribcage rotating along with the spine. If asymmetry is noted in the upper thoracic, midthoracic, thoracolumbar, or lumbar region, it should be measured with a scoliometer.Inability to bend forward at the waist, or decreased range with forward or side bending may be secondary to pain, lumbar muscle spasm, and/or tightness of the hamstrings. Any of these findings may indicate nonidiopathic etiology. The location of the prominence in relation to the convexity of a lumbar curve may provide a clue to the underlying cause. In structural scoliosis (including AIS), the rotational prominence is on the same side as the convexity of the curve. In contrast, in leg length discrepancy, the prominence is seen during sitting and on the concave side of the curve. There is no rotational component, but the iliac crest and lumbar spine are more prominent on the side with the long leg, resulting in a long curve in the shape of the letter "C". The prominence disappears if the pelvis is leveled by placement of an appropriately sized block (under the short leg) or during sitting. The Adams forward bend test is the most sensitive of the clinical examination findings for scoliosis (using the radiographic Cobb angle as the gold standard). However, the ability of the forward bend test to correctly identify patients with and without scoliosis (sensitivity and specificity, respectively) varies depending upon the skills of the examiner, the location of the curve, and the magnitude of the curve used as the gold standard. The range of sensitivity and specificity of the forward bend test (performed by school-based screeners in most cases) for varying degrees of scoliosis are as follows: Thoracic scoliosis with Cobb angle 10º - sensitivity 74 to 84 percent, sensitivity 78 to 93 percent. Thoracic scoliosis with Cobb angle 20º - sensitivity: 92 to 100 percent; specificity 60 to 91 percent. Lumbar scoliosis with Cobb angle 20º - sensitivity 73 percent; specificity: 68 percent. Scoliosis with Cobb angle 40º - sensitivity 83 percent; specificity 99 percent (with repeat screening by a more experienced screener in some cases).

Use of a scoliometer - A scoliometer (sometimes called an inclinometer) is a device used for scoliosis screening and quantification of trunk rotation. Scoliometer measurements can help in determining which patients need radiographs, but should not be used in the absence of radiographs to make decisions regarding bracing or surgery. A scoliometer is basically a version of a carpenter's level that measures the angle of trunk rotation. The scoliometer is run along the patient's spine from cephalad to caudad while the patient is in the position assumed for the Adams forward bend test. If a rotational prominence (i.e., rib or loin hump) is present, the ball in the scoliometer deviates from the center of the device. If there is a right rib prominence, for example, the right side of the scoliometer tips upward, and the ball deviates to the left. The degrees on a scoliometer do not correspond one-to-one to the degrees of curvature as measured using Cobb angles on a radiograph. Equations and algorithms have been developed to convert between scoliometer readings and Cobb angles. As a general guideline, an angle of trunk rotation of 7º corresponds to a Cobb angle of 20º. However, not all patients with radiographic scoliosis have rotation of the trunk and not all patients with trunk rotation have radiographic scoliosis. Scoliometer use is, to some extent, operator dependent. In one study, the inter-rater error for thoracic and lumbar curves were 2º and 2.2º, respectively (compared to an intra-rater error of 1.2º and 1.6º, respectively). Potential sources of error in scoliometer measurements include: the size of the ball in relation to the markings for degree increments; inconsistent identification of the apex of the curve; and inconsistent performance of the forward bend test. The sensitivity and specificity of the scoliometer to identify patients with scoliosis varies depending upon the threshold scoliometer value (i.e., 5 versus 7 versus 10 degrees). The following observations illustrate the range of findings in different studies: When scoliosis was defined by a Cobb angle of 20º, the sensitivity was 94 to 100 percent and specificity was 29 to 33 percent when a scoliometer threshold of 5º. Increasing the scoliometer threshold to 10º reduced the sensitivity to 50 to 53 percent but increased the specificity to 94 to 100 percent. A scoliometer threshold of 7º was associated with a sensitivity of 83 percent and a specificity of 86 percent. The sensitivity appears to be greater for thoracic curves. This was suggested in a study in which the sensitivity of a scoliometer threshold of 5º to detect curves of 20º was 71 percent with thoracic curves and 51 percent with lumbar curves. The specificity was the same (83 percent) at both sites.

Radiographs are required to confirm the diagnosis of scoliosis, to determine the type (congenital, neuromuscular, idiopathic) and severity, and to evaluate skeletal maturity (to determine the risk for progression).

Indications - Indications for plain radiographic evaluation in the patient with scoliosis may include: Scoliometer reading of 7º, since curves of this magnitude may require treatment. Clinically evident scoliosis (eg, a large, unambiguous curve) on physical examination Asymmetry on physical examination in skeletally immature children or in combination with a family history of scoliosis. Monitoring progression in patients with previously diagnosed AIS. In addition, magnetic resonance (MR) imaging may be indicated in patients with scoliosis and clinical or plain radiographic findings suggestive of intraspinal pathology (tumor, dysraphism, infection). These findings include: Associated neurologic signs or symptoms, including headache, neck pain, absence of abdominal reflex, and midline skin lesions (vascular, pigmentary, hair patch). Complaints of significant associated pain; computed tomography and/or bone scan also may be indicated in these patients if bone tumors or infection are suspected. Early age of onset (before 10 years) with rapid progression. Left-sided thoracic curves in children with abnormal neurologic examination. Abnormalities on plain radiographs that suggest congenital scoliosis or intraspinal pathology (eg, widening of the interpediculate space or erosion of the pedicles) or increased kyphosis. In addition, some practitioners believe that MR imaging should be performed in all children with a left-sided thoracic curve regardless of neurologic status or progression rate, all children with a curve that rapidly progresses, and all boys with a curve that demonstrates any degree of progression. However, these criteria are controversial.

Views - The initial radiographic evaluation for scoliosis should include standing, full-length posteroanterior (PA) and lateral views of the spine (C7 to the sacrum and iliac crest) exposed on a single long film cassette. PA views minimize radiation to the breasts and thyroid. The lateral view assesses spinal curvature in the sagittal plane, and need not be repeated at subsequent visits if the initial film shows the normal configuration of thoracic kyphosis and lumbar lordosis. Discrepancy in leg length, if present, should be corrected by placing an appropriate sized block under the shorter leg before radiography. Long film cassettes may not be available at all facilities. If long film cassettes are not available, sending the patient to a facility where long term cassettes are available is preferable to obtaining suboptimal radiographs on inappropriate cassettes. Lateral bending films, in which the patient actively bends as far as possible laterally to one side and then the other, demonstrate potential for surgical correction. They are used for preoperative planning of fusion levels and hardware placement, and are not necessary for diagnosis or at routine follow-up. Lateral bending radiographs should be obtained by the operating surgeon as he or she deems necessary.

Radiographic findings - Radiographs are reviewed to obtain information about the etiology, the site of the deformity, the curve pattern, the magnitude of the curve (by the method of Cobb), and evaluate skeletal maturity (with Risser sign).
General - The PA radiograph is viewed with the patient's heart on the examiner's left, as if the examiner is standing behind the patient. This is the opposite of how one typically views a chest radiograph, in which the patient's heart is to the examiner's right. Spinal radiographs should be assessed for abnormalities that are suggestive of an underlying congenital or neuromuscular etiology. These may include: Soft tissue abnormalities (eg, paraspinal mass), wedged vertebrae or hemivertebrae (indicative of congenital scoliosis), vertebral body lucency (suggestive of bone tumor), widening of the interpediculate space or erosion of the pedicles (suggestive of a spinal cord tumor, syringomyelia, diastematomyelia, or spinal dysraphism)
Curve pattern - The direction of the curve (right or left) is defined by its convexity. The location is defined by the vertebra that is most deviated and rotated from midline (the apical vertebra): Cervical - C2 to C6 Cervicothoracic - C7 to T1 Thoracic - T2 to T11 Thoracolumbar - T12 to L1 Lumbar - L2 to L4 Lumbosacral - L5 or below. There are many possible curve configurations. However, the typical curve in AIS is a right thoracic, left lumbar double curve. There are several classifications for curve patterns that are used in making decisions regarding surgery. These include the King-Moe and the Lenke classification systems.

Cobb angle - The degree of curvature in the coronal plane is measured according to the method of Cobb. The Cobb angle is formed by the intersection of a line parallel to the superior end plate of the most cephalad vertebra in a particular curve, with the line parallel to the inferior endplate of the most caudad vertebra of the curve. From a practical point of view, when these two lines are drawn, their intersection often is outside the border of the actual film. Thus, by convention, perpendiculars to the parallels are drawn, and the angle between their intersection is measured. The size of the angle is the same, but the measurements can be performed within the physical parameters of the film. In a typical double curve, two Cobb angles are measured. The Cobb angle is the accepted standard for measuring scoliosis on radiographs. However, it has some important limitations: The Cobb angle describes only one plane of the three-dimensional deformity The Cobb angle is not proportional to the severity of scoliosis in a linear fashion (i.e., a curve with a Cobb angle of 40º is more than twice as severe as a curve with a Cobb angle of 20º). Measurement of the Cobb angle is associated with variation in inter- and intra-observer measurement error of approximately 5º.

Risser sign - The Risser sign, a visual grading of the degree to which the iliac apophysis has undergone ossification and fusion, is used to assess skeletal maturity on PA spinal radiographs. The iliac apophysis ossifies in a stepwise fashion from anterolateral to posteromedial along the iliac crest. The Risser grades are as follows: 0 - No ossification 1 - Up to 25 percent ossification 2 - 26 to 50 percent ossification 3 - 51 to 75 percent ossification 4 - Greater than 76 percent ossification 5 - Full bony fusion of the apophysis. The lower the Risser grade, the more growth remaining, and the greater the risk for curve progression.

The diagnosis of AIS is made clinically and radiographically. Criteria for the diagnosis include: Age 10 years. Curvature of the spine in the coronal plain with a Cobb angle of 10º. Exclusion of other etiologies for scoliosis (congenital, neuromuscular).

The risk for progression has important implications for treatment. Unfortunately, it is impossible to predict with complete accuracy which curves will progress and which will not. Natural history studies provide some guidelines for predicting the risk for progression in relation to sex, magnitude of the curve, curve pattern, and skeletal maturity at the time of diagnosis. Sex - The risk for progression is increased 3 to 10 times in girls compared to boys. Curve magnitude - Curves with initial Cobb angle of 20 to 29º are more likely to increase by 5º than curves with Cobb angle of 5 to 19º, independent of age. Curve pattern - Double and thoracic curves have a three-fold increased risk of progression compared to nonthoracic curves. Skeletal maturity - Markers of skeletal maturity that are predictive of remaining growth potential and risk for progression include the Risser sign, chronologic age, and menarchal status (in girls). If the markers of maturity are discordant, the risk for curve progression may differ from those described below:
      - When the Risser sign is 1, the risk for progression of 5º is 22 percent for curves with Cobb angle 5 to 19º and 68 percent for curves with Cobb angle 20 to 29º.
      - When the Risser sign is 2, the risk for progression of 5º is 1.6 percent for curves with Cobb angle 5 to 19º and 23 percent for curves with Cobb angle 20 to 29º.
      - When the Risser sign is 3, the risk for progression is of 5º is less than 10 percent.
      - Patients younger than 12 years have three times the risk for progression than older patients.
      - Among girls who have had menarche at the time of presentation, 32 percent have progression of Cobb angle of more than 5º, while 68 percent have no further progression.

Adolescents with curves with low risk for progression, and in whom an underlying congenital or neuromuscular cause has been excluded, may be followed by their primary care provider if the provider feels comfortable doing so.Indications for referral to a surgeon include: Angle of trunk rotation (as measured with the scoliometer) of greater than 7º Cobb angle greater than 20º Progression of Cobb angle of more than 5º. At the time of referral, it is important to specify which method of measurement (Cobb angle or scoliometer [angle of trunk rotation]) is being used to describe the curve since the risk for progression for a curve with a Cobb angle of 10º differs from that for a curve with an angle of trunk rotation of 10º. Findings suggestive of neuromuscular scoliosis, which usually warrant MR imaging, include severe pain, left thoracic curve, and neurologic signs and symptoms. Depending upon the examination and MR findings, referral to a specialist (neurosurgeon, oncologist, orthopedic surgeon, neurologist) may be warranted.

Many states in the United States have mandated or voluntary school-based scoliosis screening programs. However, the efficacy of such programs in preventing curve progression and/or the need for scoliosis surgery is unproven. Supporters of screening programs suggest that earlier diagnosis permits conservative therapy (i.e., bracing), preventing the need for surgery. Opponents of screening programs suggest that AIS lacks the characteristics that render a disease a good candidate for screening. These characteristics include: High prevalence, substantial morbidity and mortality in untreated patients, a preclinical phase that can be detected by a screening test that is highly sensitive and specific, benefit to preclinical detection (eg, ability to alter the natural history), availability of effective treatment.

Limitations to the efficacy of school-based screening for AIS in asymptomatic patients include: The low prevalence of AIS requiring intervention (0.3 to 0.4 percent) increases the likelihood that a positive screen will be a false positive. In one review, nearly 450 children needed to be screened to detect one child who needed treatment. Potential harms of false positive screening include unnecessary anxiety, time lost from school or work for follow-up or specialty care, radiation exposure, and adverse psychosocial effects (particularly related to brace wear). Untreated AIS does not result in substantial morbidity or mortality in most cases. The Adams forward bend test has variable sensitivity and specificity depending upon the examiner and the curve magnitude used as the gold standard. The inter-rater error of scoliometer measurement is approximately 2º. In addition, there is not a one-to-one correlation between the scoliometer measurement and the Cobb angle (the gold standard for diagnosis). The benefit of preclinical detection is unproven. Most curves detected through screening do not progress to the point of needing surgical intervention. Most cases requiring surgical treatment are detected without screening. The efficacy of bracing for AIS is disputed. Several strategies have been proposed to improve the efficacy of scoliosis screening programs. These include the development and use of more objective criteria for referral, screening only immature females (selective screening), and repeat screening rather than immediate referral for borderline cases. Some of these strategies (repeat screening, more objective criteria, increased threshold for referral) were incorporated into a screening program. The sensitivity and specificity of the forward bend test to detect patients with a Cobb angle of 40º were 83 and 99 percent, respectively, with repeat screening. However, only 8 percent of patients with a positive screening test had Cobb angle of 40º because of the low prevalence of AIS of this severity. The low prevalence of AIS with Cobb angle of 40º cannot be changed by altering the logistics of school-based screening programs.

Recommendations - A spinal examination should be included in the physical examination of children and adolescents at routine health supervision visits. Spinal examination is particularly important before the pubertal growth spurt (at approximately 10 years). In addition, pediatric health care providers should be prepared to evaluate patients for scoliosis when it is discovered incidentally or through a school-based screening program, or when the adolescent or parents express concern about scoliosis. The American Academy of Family Physicians recommend against the routine screening of asymptomatic adolescents for AIS. The Canadian Task Force on the Periodic Health Examination concluded that there is insufficient evidence on which to make a recommendation for or against routine scoliosis screening. The American Academy of Orthopaedic Surgeons and the Scoliosis Research Society recommend school screening for scoliosis with the forward bend test (at ages 11 and 13 for girls and at age 13 or 14 for boys). The Bright Futures guidelines recommend noting the presence of scoliosis during the physical examination of children and adolescents 8 years of age.

Clinical features Scoliosis is a lateral curvature of the spine usually accompanied by rotation. There are three broad categories of scoliosis: congenital, neuromuscular, and idiopathic. Idiopathic scoliosis is a diagnosis of exclusion and is classified according to the age of onset. Adolescent idiopathic scoliosis (AIS, also called late-onset idiopathic scoliosis) has onset after age 10 years and is the most common type of scoliosis. The prevalence of AIS is approximately 3 percent, but only 10 percent of adolescents with AIS require treatment (0.3 percent of the population). The natural history of untreated scoliosis is one of stabilization or progression. Untreated curves progress in approximately two-thirds of skeletally immature patients before they reach skeletal maturity and may continue to progress after skeletal maturity, but at a diminished rate. Most patients with untreated AIS have little, if any, functional limitation or pain in adulthood. Patients with scoliosis usually come to medical attention as a result of truncal asymmetry noted by the patient or parents, during school-based scoliosis screening, or as an incidental finding during physical examination.

The evaluation for scoliosis centers on exclusion of an underlying etiology, assessment of the magnitude of the curve, and the risk for progression. Important aspects of the history include age of onset, rate of progression, associated findings (i.e., pain, neuromuscular complaints, shortness of breath), family history of scoliosis, pubertal development, menarchal status (in girls), and past history of lower limb trauma, infection, or arthritis. Important aspects of the general examination include assessment of height and pubertal stage, bilateral palpation of the iliac crests and posterior inferior iliac spines, measurement of leg length, examination of the skin, and neurologic examination including assessment of abdominal reflexes. Examination for scoliosis includes inspection, the Adams forward bend test, and if asymmetry is noted, measurement of the angle of trunk rotation with a scoliometer. Radiographs are indicated for patients with an angle of trunk rotation as measured with the scoliometer of 7º and clinically obvious scoliosis. In addition, radiographs may be indicated in skeletally immature patients with asymmetry on examination and a family history of scoliosis. The initial radiographic evaluation for scoliosis should include standing, full-length posteroanterior and lateral views of the spine (C7 to the sacrum and iliac crest) exposed on a single long film cassette. Important radiographic findings include assessment of the paravertebral soft tissues and the bony spine, the direction and magnitude of the curve(s), and skeletal maturity (i.e., the Risser sign). Magnetic resonance (MR) imaging is indicated in patients with associated neurologic signs or symptoms, early age of onset with rapid progression, and abnormalities on plain radiographs that suggest congenital scoliosis or intraspinal pathology. MR imaging also may be indicated in patients with complaints of significant pain and/or left thoracic curves. The diagnosis of AIS is made clinically and radiographically. Criteria for the diagnosis include: age 10 years at onset, Cobb angle of 10º, and exclusion of other etiologies for scoliosis. The risk for progression is directly related to the magnitude of the curve and indirectly related to skeletal maturity at the time of diagnosis.

Referral Indications for referral to specialist include angle of trunk rotation (as measured with the scoliometer) of 7º, Cobb angle 20º, and progression of Cobb angle of >5º. Screening A spinal examination should be included in the physical examination of children and adolescents at routine health supervision visits.