Clinical Guidelines for Family Physicians

Screening for adolescent idiopathic scoliosis


 

The United States Preventive Services Task Force (USPSTF) has issued recommendations on screening for idiopathic scoliosis in asymptomatic children and adolescents aged 10-18 years.1 This recommendation concluded that the current evidence on the benefits and harms of screening is insufficient (I statement) and updated its 2004 recommendation against routine screening, in which it had concluded that the harms of screening exceeded the potential benefits (D recommendation).

Importance

Adolescent girl bending over stretching and touching her toes/ Wavebreakmedia/Thinkstock
The prevalence of idiopathic scoliosis (defined as Cobb angle greater than 10 degrees) ranges from 1%-3% in adolescents aged 10-16 years. Incidence estimates for spinal curvature of greater severity are 1% (Cobb angle greater than 20 degrees) and 0.4% (Cobb angle greater than 40 degrees). Severe spinal curvature may be associated with adverse long-term health outcomes including pulmonary problems, back pain, social and psychological effects, disability, cosmetic deformity, and reduced quality of life.

Screening methods

The USPSTF concluded that currently available screening tests can accurately detect adolescent idiopathic scoliosis. Screening methods include visual inspection using the forward bend test, use of scoliometer measurement of the angle of trunk rotation during forward bend test with a rotation of 5 degrees–7 degrees recommended to be referred for radiography, and Moiré topography that enumerates asymmetric contour lines on the back (values greater than 2 are referred to radiography).

The USPSTF reviewed seven fair-quality observational studies (n = 447,243) and concluded that screening with a combination of forward bend test, scoliometer measurement and that Moiré topography had the highest sensitivity (93.8%) and specificity (99.2%), a low false-negative rate (6.2%), the lowest false-positive rate (0.8%), and the highest positive predictive value (81%). Sensitivity was lower when screening programs used only one or two screening tests, and single screening tests were associated with highest false-positive rates.

In general, the potential harms associated with false-positive results include psychological harm, chest radiation exposure, and other unnecessary treatment, but the USPSTF did not find evidence on the direct harms of screening.

Effectiveness of intervention or treatment

Bracing: The USPSTF found five studies (n = 651) that evaluated the effectiveness of treatment with three different types of braces. The average ages of participants ranged from 12 to 13 years, and their curvature severity varied from Cobb angle of 20 degrees to 30 degrees. The largest study (n = 242) was a good-quality, international, controlled clinical trial known as the Bracing in Adolescent Idiopathic Scoliosis Trial; it demonstrated significant benefit and quality-of-life outcomes associated with bracing for 18 hours/day. In this study, the rate of treatment success in the as-treated analysis was 72% in the intervention group and 48% in the control group. The rate of treatment success in the intention-to-treat analysis was 75% in the intervention group and 42% in the control group. The number needed to treat was three to prevent one case of curvature progression past 50%.

Exercise: The USPSTF found just two trials (n = 184) that evaluated the effectiveness of tailored physiotherapeutic, scoliosis-specific exercise treatments. The participants were older than 10 years and had Cobb angles ranging from 10 degrees to 25 degrees. At the 12-month follow-up, the studies showed significant improvement, including those in quality-of-life measures. In one of the trials, the intervention group had a Cobb angle reduction of 4.9 degrees while the control group had an increase of 2.8 degrees.

Harms: Only one good-quality study (n = 242) reported harms of bracing, which include skin problems, body pain, physical limitations, anxiety, and depression. The USPSTF did not find any studies that assessed the harms of treatment with exercise or surgery.

Association between spinal curvature severity and adult health outcomes

The USPSTF did not find any studies that directly addressed whether changes in the severity of spinal curvature in adolescence resulted in changes in adult health outcomes. The USPSTF did review two fair-quality retrospective, observational, long-term, follow-up analyses (n = 339) of adults diagnosed with idiopathic scoliosis in adolescence and treated with either bracing or surgery. Quality of life measurements, pulmonary consequences, and pregnancy outcomes were not significantly different between the two treatment groups or between those treated and those simply observed. However, those treated with bracing did report more negative treatment experience and body distortion.

Recommendation of others

The Scoliosis Research Society, American Academy of Orthopedic Surgeons, Pediatric Orthopedic Society of North America, and American Academy of Pediatrics issued a joint position statement in September 2015 recommending that screening examinations for scoliosis should be performed for females at ages 10 and 12 years and for males at either 13 or 14 years.2

Their rationale, articulated in the statement and in an editorial in JAMA accompanying the publication of the USPSTF statement, is primarily based on findings in the Bracing in Adolescent Idiopathic Scoliosis Trial that showed a 56% decrease in the rate of progression of moderate curves to greater than 50 degrees. The evidence that intervention works – along with concerns about costs, family burden, loss of school time, risks of surgical complications, and the 22% need for long-term revision surgery – makes avoidance of progression of curves in scoliosis a high-value issue. In addition, they reasoned, the screening trials from which the false-positive values were derived were primarily school-based screening and not done in physician offices.

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