Idiopathic scoliosis affects 2% of adolescents. In adolescents with an immature skeleton, bracing is commonly recommended if there is curve progression to 25 to 45 degrees. A randomized trial comparing bracing with watchful waiting is under way. The latest article in our Clinical Practice series comes from Dr. M. Timothy Hresko at Boston Children’s Hospital.
Scoliosis is the most common deformity of the spine. Although the term “scoliosis” may be used by some to describe any curvature of the spine noted on clinical examination or incidental finding on radiograph, the term should be reserved for a precise condition. Scoliosis is defined as a lateral curvature of the spine that is 10 degrees or greater on an upright coronal radiograph while recognizing that the image is a representation of a three dimensional deformity.
• How is scoliosis characterized?
Scoliosis is typically categorized by cause. Congenital scoliosis describes an anatomic anomaly due to failure of formation or segmentation of the vertebral column which, with growth, may lead to progressive spinal deformity. Neuromuscular scoliosis describes deformity secondary to dysfunction of the central nervous system such as with spastic quadriplegia, the peripheral neuromuscular unit as with muscular dystrophy and spinal muscular atrophy, or combined sensory and motor dysfunction as with syringomyelia. Scoliosis is common in neurofibromatosis and in certain connective tissue diseases such as Marfan’s or Ehlers-Danlos syndromes. Most patients, however, do not have a recognized cause (“idiopathic scoliosis”). Idiopathic scoliosis is subclassified as infantile (0 to 3 years of age), juvenile (3 to 10 years of age), adolescent (above age 10), or adult. Scoliosis in an adult may also develop due to degenerative disc disease.
• What is the natural history of scoliosis?
Idiopathic scoliosis is not progressive in most patients. The likelihood of progression is higher in girls and in those with greater curvature severity and more remaining growth. Natural history studies have shown that scoliosis deformity less than 30 degrees at the end of growth rarely worsens in adulthood whereas scoliosis of greater than 50 degrees predictably worsens throughout adulthood at a rate of 0.75 to 1.00 degree per year. Therefore, the skeletally immature patient with a scoliosis of greater than 25 to 30 degrees is at risk for progression. Thoracic spine growth in the preadolescent is necessary to achieve adult chest volume, as lung volume doubles from age 10 to skeletal maturity. Adolescent patients with thoracic scoliosis of greater than 50 degrees are at increased risk of shortness of breath later in life (odds ratio approximately 15 at 30-year and 4 at 50-year follow up, compared to age-matched norms). Lung volumes are diminished compared to norms when thoracic idiopathic scoliosis reaches 70 degrees, and symptomatic restrictive pulmonary disease is common in patients whose curve magnitude exceeds 100 degrees.
Morning Report Questions
Q: What is the appropriate evaluation in a patient with scoliosis?
A: The physical examination is fundamental in diagnosing scoliosis and eliminating underlying conditions that may cause spine deformity. Classic findings of scoliosis on examination are shoulder and scapular asymmetry, rib prominence on forward flexion (Adams test), and asymmetry of waist and trunk. Skin examination is warranted to rule out manifestations of neurofibromatosis (cafe au lait spots, subcutaneous fibromas, and axillary freckling) and an ectodermal anomaly such as midline spinal dimpling, suggestive of incomplete closure of the neural tube. The extremities should be assessed for arachnodactyly or joint laxity suggestive of heritable connective tissue disorders, as well as for leg length inequality, which may cause a false positive on the Adams test. If a connective tissue disorder is suspected, referral for genetic and cardiac evaluation is appropriate. Asymmetric muscle, sensory, or reflex testing may indicate nerve dysfunction seen with syringomyelia. The spinal radiograph remains the accepted standard of imaging for evaluation of scoliosis. Active bending radiographs are not needed in routine evaluation but are indicated to evaluate the flexibility of the spine in patients who are surgical candidates.
Q: In a patient diagnosed with scoliosis, what options for treatment are available?
A: Most nonprogressive idiopathic scoliosis does not require treatment, and many patients are managed by the primary care physician with periodic assessments during rapid growth. Many nonoperative treatment options such as physical therapy, surface electrical stimulation, and chiropractic treatment have been proposed but supporting data are lacking from controlled studies. Intervention by a corrective cast program is recommended for progressive deformity in children under age 3. Orthotic brace management using a rigid thoracolumbar orthosis is currently the preferred treatment for children age 3 through adolescence who are at risk of progressive scoliosis, i.e., with curve magnitude of 25 to 45 degrees and significant growth remaining. The goal of brace treatment is to arrest the progression of scoliosis below the level requiring surgical treatment. Results from bracing appear optimal when average daytime brace wear is at least 12 hours; a typical brace prescription is for 18 to 20 hours per day, as full compliance is rarely achieved. Operative treatment is indicated when progressive scoliosis exceeds 45 to 50 degrees in the skeletally immature patient, or when progression or associated pain occurs after skeletal maturity.