Scoliosis refers to an S-shaped or C-shaped spinal deformity in the coronal plane (when looking directly at the person). In addition to a spinal curvature, patients also frequently develop a rotational deformity of the spine, whereby the rib and trunk rotate causing a rib hump or prominence on one side of the back.
Although scoliosis is not an extremely common condition seen in children, approximately 2-3% of school age children are reported to have a curvature greater than 10 degrees. However, only three out of 1000 are noted to have a curvature greater than 30 degrees. Children with a small curve less than 20 degrees are at low risk of having the deformity get worse after skeletal maturity (after they finished puberty and are done growing). However, adolescent patients with a curvature greater than 50 degrees have a very high likelihood of having the curve get worse over time. Children with scoliosis typically do not have pain. The principal reason to perform surgery is to correct a scoliosis curvature and prevent it from becoming worse. Thoracic curves greater than 80 degrees have been shown to cause diminished chest volume and breathing capacity, and may affect heart function in some patients. Large lumbar and thoracolumbar curves often become painful in adulthood, and may lead to significant spinal imbalance.
There are three main causes, or etiologies, of structural scoliosis in children. The most common is idiopathic scoliosis. Idiopathic is a medical term meaning that the cause is unknown, and it occurs it an otherwise totally normal, healthy child. Congenital scoliosis occurs because of a developmental defect – the spine bones failed to form normally at birth and cause the spine to become curved. Neuromuscular scoliosis occurs because a child has an underlying neuromuscular disorder that is causing the spine to develop a curvature. Other rare causes of scoliosis in children include metabolic disorders, spinal dysraphism, and genetic syndromes.
Types of Scoliosis in Children
- Infantile – 0-3 years old
- Juvenile – 3-8 years old
- Adolescent – 8-18 years old
- Segmentation defect
- Unilateral unsegmented bar
- Laminar synostosis
- Bloc vertebrae
- Formation defect
- Partial unilateral – wedge vertebrae
- Complete unilateral – hemivertebrae
- Semisegmented hemivertebrae
- Nonsegmented hemivertebrae
- Segmentation defect
- Cerebral palsy
- Charcot-Marie-Tooth disease
- Muscular dystrophy
- Marfan syndrome
- Rheumatoid arthritis
Of note, there are other musculoskeletal conditions that can cause nonstructural scoliosis. This means that the primary problem is not in the spine and the curve is caused by something else. Examples of causes of nonstructural scoliosis are leg length discrepancy, postural weakness, and pelvic obliquity.
Children with scoliosis rarely have pain or disability related to the spinal curvature. That is one reason why some children are not realized to have scoliosis until it becomes quite severe. If the curvature is severe and uncompensated, patients may feel as if they are “off balance” and have trouble walking. This occurs because their head and torso is frequently shifted forward and/or to the side. Children rarely have back or leg pain (sciatica), or other symptoms such as numbness or weakness. If present, a magnetic resonance imaging (MRI) test should be obtained to evaluate the possibility of a neurologic lesion, tethered cord, dysraphism, or other abnormality.
The most prominent finding on physical examination is the spinal deformity and truncal shift, either in the coronal plane or sagittal plane, or both. Children will often have a marked rib hump and rotational deformity of the rib cage. There is rarely spinal tenderness or spasm. Most patients have normal range-of-motion of the lumbar spine. The neurologic examination is usually always normal, unless there is an associated neurologic condition.
X-rays are the most important imaging study to obtain when evaluating scoliosis. Long plate, tri-fold anteroposterior (AP – x-ray is taken facing the patient directly) and lateral (x-ray is taken from the side view) x-rays should be taken with the patient standing in order to adequately evaluate a spinal deformity – both scoliosis and kyphosis. Side-bending x-rays are also obtained to understand how flexible a spinal curvature is before surgery is undertaken. A magnetic resonance imaging (MRI) test may also be indicated if there is any type of neurologic abnormality or if a left thoracic curvature is noted. A computed tomography (CT) scan with reconstructions should be obtained in patients with congenital scoliosis so as to thoroughly evaluate the vertebral abnormality. A myelogram may also be required to adequately evaluate the presence of stenosis or neurologic compression.
There are no laboratory tests used to diagnose scoliosis. Occasionally, specific tests are ordered to rule out infection or other medical/rheumatologic conditions.
The diagnosis of scoliosis may be suspected, particularly if the above-mentioned physical findings are present. A thorough physical examination is performed to ensure there no other musculoskeletal conditions present that could be causing the spinal curvature. An x-ray is required to confirm the diagnosis, as well as to evaluate the severity of the deformity and curvature. Occasionally, patients may have another musculoskeletal abnormality, such as pelvic obliquity or a leg length discrepancy that is the underlying cause of the spinal deformity, and care must be taken to identify these other causes so as to render treatment appropriately.
The treatment of children with scoliosis depends on the type of scoliosis, as well as the severity of spinal curvature. Skeletally immature (still growing) children with idiopathic scoliosis are usually treated with a brace if the curve is greater than 25 degrees. Surgery is considered if the curve becomes greater than 40-50 degrees, especially if the child is still growing. The recommended surgical procedure is a posterior (back incision) spinal fusion with instrumentation, which means the spine bones are straightened and mended together with bone graft and metal rods/screws. The success rate of surgery is very high and the complication rate is very low. Children are generally pleased with the results, as well as the cosmetic appearance.
Children with congenital scoliosis may be recommended for brace treatment at an early age if the curve is progressive. Although bracing may not be highly effective, it can be helpful for some. Children with a unilateral unsegmented bar or a free hemivertebrae are at high risk of progression, and often require surgery at a young age. Regardless, children with congenital scoliosis should be checked regularly at 6-9 month intervals, with new x-rays on each visit. A posterior spinal fusion with instrumentation is usually performed, although an anterior approach (incision through the chest or abdomen) is sometimes performed to address the congenital defect if it is located in the anterior portion (front part) of the spine.
Children with neuromuscular scoliosis should also be checked regularly at 6-9 month intervals, with new x-rays on each visit. A child that has a progressive curvature greater than 30-40 degrees should generally be recommended for surgery, since the risk of continued progression is so high. A posterior spinal fusion with instrumentation is usually performed.
Ceballos T, et al: Prognosis of infantile scoliosis. J Bone Joint Surg Am 1980;62:863
Frigueiredo UM, James JP: Juvenile idiopathic scoliosis. J Bone Joint Surg Am 1981;63:61
Lonstein JE, Carlson M: Prognostication in idiopathic scoliosis. J Bone Joint Surg Am 1984;66:1061.
Mcmaster MJ, Ohtsuka K: The natural history of congenital scoliosis: a study of 251 patients. J Bone Joint Surg Am 1982;64:1128.
Rowe DE, Bernstein SM, Riddick MF, et al. A meta-analysis of the efficacy of non-operative treatments for idiopathic scoliosis. J Bone Joint Surg Am 1997;79:664-674.
Spoonamore MJ, Dolan LA, Weinstein SL. Use of the Rosenberger brace in the treatment of progressive adolescent idiopathic scoliosis. Spine 2004;29(13):1458.
Weinstein SL, Dolan LA, Spratt K, Peterson KK, Spoonamore MJ, Ponseti IV: Health and Function of Patients with Untreated Idiopathic Scoliosis: A 50-Year Natural History Study. JAMA 2003;289:559.
Weinstein SL, Ponseti IV: Curve progression in idiopathic scoliosis: long term follow-up. J Bone Joint Surg Am 1983;65:447.
White SF, Asher MA, Lai SM, Burton DC. Patients’ perception of overall function, pain, and appearance after primary posterior instrumentation and fusion for idiopathic scoliosis. Spine. 1999;24(16):1693.
Winter RB, Moe J, Lonstein JE: Posterior spinal arthrodesis for congenital scoliosis: an analysis of 290 patients 5 to 19 years old. J Bone Joint Surg Am 1984;66:1188.