AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Multimedia
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Multimedia
• References

The term scoliosis is derived from the Greek word skol, meaning "twists and turns" and refers to a sideward (right or left) curve in the spine. Scoliosis is not a simple curve to one side but, in fact, is a more complex, 3-dimensional deformity that often develops in childhood.

History of the Procedure

Probably the oldest mention of scoliosis is in ancient Hindu mythology (3500 to 1800 BC), in which Krishna corrects the hunchback of one of his followers. Hippocrates (460 to 377 BC) wrote about scoliosis and devices to correct it. The term infantile scoliosis was first used by Harrenstein in 1930 and by James in 1951 in describing the clinical entity idiopathic infantile scoliosis.^{1, 2, 3}

Problem

The term infantile scoliosis is specifically used to describe scoliosis that occurs in children younger than 3 years. Other terms for scoliosis also depend on the age of onset, such as juvenile scoliosis, which occurs in children aged 4-9 years, and adolescent scoliosis, which occurs in those aged 10-18 years. These terms, however, are now being replaced by the broader terms early-onset scoliosis and late-onset scoliosis, depending on whether the scoliosis occurred before or after 5 years of age.

In 80% of cases of scoliosis, there is no obvious cause; this is termed idiopathic scoliosis. In the remaining 20% of cases, a definite cause can be found. These cases are divided into 2 types: nonstructural (functional) and structural scoliosis, which could be part of a well-recognized syndrome (syndromic scoliosis), congenital spinal column abnormalities (congenital scoliosis), neurologic disorders, and genetic conditions.

The syndromes that can produce congenital scoliosis are VATER syndrome (vertebral anomalies, anorectal anomalies, tracheo-esophageal fistula, and renal anomalies), VACTERL syndrome (vertebral anomalies, anorectal anomalies, tracheo-esophageal fistula, renal and vascular anomalies, and cardiac and limb defects), Jarcho-Levin syndrome, Klippel-Feil syndrome, Alagille syndrome, Wildervank syndrome, Goldenhar syndrome, Marfan syndrome, and MURCS association (mullerian, renal, cervicothoracic, and somite abnormalities).

The congenital anomalies of the vertebral spinal column include defects of segmentation (block vertebra, unilateral bar) and defects of formation (hemivertebra — fully segmented, semisegmented, incarcerated and nonsegmented, wedge vertebra). The neurologic deficits in congenital scoliosis may be secondary to the spinal deformity or may be associated with vertebral anomalies (spinal dysraphism — diastematomyelia, myelocele, myelomeningocele, meningocele). A higher incidence of idiopathic scoliosis has been reported in families of children with congenital scoliosis. Spondylocostal dysostosis (Jarcho-Levin syndrome) has a genetic etiology.^{4, 5, 6, 7}

Related eMedicine topics:
Idiopathic Scoliosis
Neuromuscular Scoliosis
Scoliosis, Idiopathic (Radiology)

Related Medscape topics:
Resource Center Neonatal Medicine
Resource Center Pediatrics/Neonatal Care Nursing
Resource Center Spinal Disorders
Specialty Site Pediatrics
Specialty Site Orthopaedics

Frequency

Infantile scoliosis is a rare condition, accounting for less than 1% of cases of idiopathic scoliosis in North America; in Europe, the rate is 4%.

Sex: Males account for 60% of the cases of early-onset scoliosis; 90% of the cases of early-onset scoliosis resolve spontaneously, but the other 10% of cases progress to a severe and disabling condition. Females constitute 90% of late-onset cases and need close monitoring to intervene at appropriate times.

Etiology

Although the exact cause of idiopathic infantile scoliosis is not known, hypotheses have been proposed on the basis of epidemiologic evidence^{4, 5, 6, 8, 9}:

• One theory holds that the mechanical factors during intrauterine life are responsible for the higher incidence of plagiocephaly, developmental dysplasia of the hip, and scoliosis on the same side of the body.
• A second hypothesis suggests multifactorial causes, including predisposing genetic factors that are either facilitated or inhibited by external factors such as defective motor development or collagen disorders, joint laxity, and nursing posture of the infant.
• Other associations include older mothers from poorer families, breech presentation, and premature and male low-birth-weight babies.

Pathophysiology

Most of the curves in the spine develop during the first year of life, and strong correlation has been found between the nursing posture of the infant and development of the curve. It is less common in the United States than in Europe, where babies are nursed in the supine position. Infants have a natural tendency to turn toward the right side, and because of plasticity of the infant's axial skeleton, this can lead to development of plagiocephaly, bat ear on the right side, and curvature of the spine toward the left side.⁸

Clinical

Infantile scoliosis is usually detected during the first year of life either by the parents or by the pediatrician during routine examination of the infant. Usually, a single long thoracic curve to the left is present; less often, a thoracic and lumbar double curve is noted. A child who is diagnosed with scoliosis requires a thorough clinical and radiologic examination to exclude any congenital, muscular, or neurologic causes.

INDICATIONS

Section 3 of 10  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Multimedia
• References

There are 3 management options for infantile scoliosis: observation, orthosis, and operative. The decision when to use each of these is based on the rib-vertebral angle difference (RVAD), established by Mehta in 1972 (see Image 1).¹⁰ The RVAD is a useful guide in distinguishing between resolving and progressive idiopathic infantile scoliosis.

The rib-vertebrae angle is measured by (1) drawing a line perpendicular to the middle of the upper or lower border of the apical vertebrae of the curve and then (2) measuring the angle this line makes with medial extension of another line drawn from the mid point of the head to the mid point of the neck of the rib, just medial to the beginning of the shaft of the rib. The difference between the right and the left side (concave and the convex side) is the RVAD.

The apical vertebra is the vertebra at the curve of the apex. If there are the same number of vertebrae between the superior and the inferior end vertebrae, there will be 2 apical vertebrae.

For scoliosis curves with an RVAD of less than 20°, observation every 4-6 months is sufficient. If the RVAD is more than 20° or if it is not flexible clinically (ie, curve cannot be corrected even slightly with different postures, especially lateral bending), then it is considered to be progressive until proven otherwise.

Management with orthosis is necessary when the curve is considered to be progressive or if a compensatory curve has developed. Various types of orthosis are available for children younger than 3 years. The most commonly used orthoses are the hinged Risser jacket; the plaster spinal jacket (Cotrel EDF [elongation, derotation, flexion] type) applied under anesthesia; the Milwaukee brace; and the Boston brace. The brace should be used for 23.5 hours a day and should be removed only for exercises and swimming. It needs to be used until skeletal maturity is attained, because curves usually do not progress after skeletal maturity; however, curves may progress in spite of using a brace.^{11, 12}

Spinal deformity in scoliosis progresses during periods of peak growth velocity. The first spinal growth peak occurs at 2 years of age, and the second peak occurs during the prepubescent period.

Operation is usually an option only for children in older age groups (ie, around age 10 years), and segmental posterior wiring to two L-rods without fusion is preferable until combined posterior and anterior fusion can be done. These procedures, however, have been associated with complications in 50% of patients. 

Because of advances in instrumentation, pedicle screw instrumentation can be performed for children with further growth potential. In these patients, a growing rod is used, which is associated with fewer complications than surgical fixation using L-rods. The disadvantage associated with the growing rod is that every 6 months the posterior aspect has to be opened to lengthen the rod, which increases the risk of infection; however, if the curve is severe or increases despite the use of orthosis, a short anterior and posterior fusion is recommended to prevent crankshaft phenomenon.

RELEVANT ANATOMY

Section 4 of 10  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Multimedia
• References

The spine is made up of 33 individual vertebrae that form a column. The spine is divided into 5 regions, starting from the top:

• Cervical - 7 vertebrae
• Thoracic - 12 vertebrae
• Lumbar - 5 vertebrae
• Sacrum - 5 vertebrae
• Coccyx - 4 vertebrae

The sacrum and coccyx are fused in the adult. The spine provides a protective function for the spinal cord; bears and distributes the weight of the body; provides an area for attachment of ligaments and muscles; and is the site for production of red blood cells. Together, all the vertebrae form a flexible structure providing mobility for the body to bend forward or sideward.

Each vertebra has a cushionlike fibrous structure called a disk, which acts like a shock absorber during movements of the spine. The disk is made up of a soft, jellylike central nucleus pulposus surrounded by a ring of fibrous tissue called an anulus, which is actually a strong ligament between 2 adjacent vertebrae.

Developmentally, the spine of the fetus is C-shaped, with concavity in the front (kyphotic) of the thoracic region; this is called the primary curve. Two secondary curves develop after birth, with concavity occurring anteriorly (lordosis); one of the secondary curves develops in the cervical region as the infant starts to hold up the neck, and the second curve develops in the lumbar region when the child starts to walk. Normally, there are no sideward (scoliosis) curves, so that the spine looks straight when viewed from behind or from the front.

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Multimedia
• References

Lab Studies

• Scoliosis has been seen in families, and research is ongoing to identify any scoliosis-related genes^{4, 5}

Imaging Studies

• Radiographs of the spine in infants is taken with the child held up by the arms. As the patients are usually very young, the way to perform radiographs are either for the parents to hold the children or for a pediatric immobilizer and positioner such as the Pigg-O-Stat to be used. The way of establishing the severity of the scoliosis in an infant is to calculate the RVAD in the radiographs. Radiographs and rib-vertebral angle difference (RVAD) calculations need to be repeated every 2-3 months to determine whether the curve is progressing or regressing.
• Anteroposterior radiographs may also be used to evaluate the severity of the curve; however, it may not be accurate, as it assesses the 3-dimensional deformity in a 2-dimensional projection. Still, it is a reasonable estimation of the severity and, hence, is commonly used in the evaluation of scoliosis. It is the angle between the superior endplate of the superior end vertebra and the inferior endplate of the inferior end vertebra. As these lines normally pass beyond the screen of the plain radiographs, perpendicular lines are drawn to these lines and the angle subtended between them, which is called the Cobb angle (see Image 2). The end vertebrae are the most superior and inferior vertebrae in the curve; they are differentiated by the opening of the intervertebral disk space caused by crowding on the concave surface. These vertebrae are the least displaced and rotated and have maximally tilted end plates.^{13, 14}

Other Tests

• CT scanning can be used to get a detailed picture of the scoliosis curve. Because spinal fusion is a major surgical treatment modality, patients need to be assessed with respect to their ability to withstand a major surgical procedure and need to have tests done for hemoglobin level and respiratory function.¹⁵
• MRI scanning is necessary in moderate to severe infantile scoliosis, because the neural axis abnormalities associated with infantile scoliosis have been reported to range from 21-50%. The common abnormalities are Arnold-Chiari type I malformation and syringomyelia. Hence, whole-spine MRI is indicated before surgery. The current recommendation is for patients with infantile scoliosis with a Cobb angle greater than 20º.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Multimedia
• References

Surgical therapy

The decision whether to operate on a patient with scoliosis depends on many factors, such as the following:

• Time of onset of the curve (early-onset curves are the ones that most often require surgery)
• Degree and site of the curve (a thoracic curve greater than 40° or a lumbar curve greater than 60° in a child aged 10-12 years often requires surgery)
• Response to conservative treatment with a brace
• Rate of progression of the curve
• Parents' and patients' acceptability of the cosmetic appearance of the spine

Growing rods without fusion is preferable until combined posterior and anterior fusion can be done. Growing-rod systems (eg, pediatric Isola instrumentation) may be utilized to prevent curve progression; extensions are needed every 6 months to keep pace with the child's growth until the child has adequate trunk length, which is usually between the ages of 11 and 15 years. Then the child needs a definitive fusion once skeletal maturity is reached, which involves removal of implants and reinstrumentation. Also, if there is evidence of congenital problems or thoracic insufficiency, another type of growing-rod system (eg, the vertical expandable prosthetic titanium rib [VEPTR]) may first be used.^{16, 17, 18, 19, 20}

Vertical expandable prosthetic titanium rib

VEPTR is a recent development in the management of severe scoliosis in skeletally immature patients (see Images 4-5). This is usually indicated in patients having thoracic insufficiency syndrome (TIS).²¹ Apart from having a spine deformity, patients may have a deformity of the thoracic cage, such as fused ribs or a hypoplastic thorax. VEPTR helps rebuild the chest wall and correct the spine deformity, thereby allowing the lungs to expand to achieve normal functioning. There are a number of types of VEPTR devices, such as the following:

• Cradle-to-cradle — Used in cases of fixed or missing ribs, severe scoliosis, and hypoplastic thorax
• Cradle-to-lumbar lamina hook — Used when scoliosis involves the lumbar region or when lower ribs are absent
• Cradle-to-S-hook — Attaches upper ribs to the pelvis and is useful in cases in which lower ribs are absent and lumbar bones are weak

Pediatric Isola spine system

The Isola system (see Image 3) consists of screws with washers that are applied posteriorly to anteriorly; horizontal to the frontal plane of the vertebral body; and parallel to the apex of the curvature. Screws may be applied through the staples. Closed-top end screws are placed first. A rod is then contoured along the curvature and is cut to size, so that it extends about 1 cm beyond the end screws. The rod is passed between the 2 end screws, and open-end screws with staples are then placed in the remaining intervening vertebrae, using the contoured rod as a guide for positioning of the screws. Caps are placed on the intermediate screws, and the rod is rotated approximately 180° to obtain both a coronal correction and a sagittal correction.²²

Further correction can be accomplished by opening the vertebral spaces with a Cobb elevator after tightening one of the intermediate screws. At this stage, further correction can also be accomplished by applying distraction between the screw connector bodies. The disk space that is created can now be completely filled with bone graft material. Vertebral screws are compressed centrally, starting from the top of the screw to the bottom and then to the top of the next screw. The final compression is applied across the apical vertebrae.

Rods are inserted to prevent progression of the curve, and the rods are extended every 6 months to keep pace with the child's growth. Hooks are used as anchors on the upper part of the curve, and pedicle screws are used in the lower part of the curve. At the apex of the curve, the muscle is not dissected, so as to maintain the blood supply to the bone at the apex.

Preoperative details

• Improve the general condition of the child by providing appropriate nutrition and making sure the child is capable of undergoing general anaesthesia
• Any infection should be treated appropriately
• Flu prophylaxis is required for children with lung problems
• Pneumonia prophylaxis is required for children on a ventilator

Intraoperative details

Operative details for VEPTR

• The patient is placed in the lateral decubitus position.
• Two incisions are made: a large J-shaped incision, medial to the border of the scapula and curving anteriorly, and a small incision made distally so as to apply the distal end of the prosthesis to the spine.
• The prosthesis is applied over the rib cage and beneath the skin and muscle.
• After the proximal and distal ends are attached, the device is distracted with the aid of expansion pliers.

Intraoperative spinal cord monitoring (somatosensory evoked potential) has been found to be useful in these cases. If somatosensory evoked potential changes intraoperatively, then decreasing the VEPTR expansion may resolve the issue. Spinal cord monitoring can decrease the incidence of neurologic complications following excessive correction from surgery.

Postoperative details

The surgical wounds need to be protected with padding to prevent injury. The prosthesis needs to be expanded every 4-6 months as the child grows. Expansion requires that a small incision be made at the site of distraction. When the child stops growing, the device can be removed, and other definitive procedures, such as rib spreading, may be necessary.

COMPLICATIONS

Section 7 of 10  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Multimedia
• References

The risks associated with anesthesia include bleeding; lung infection; wound problems (eg, healing, infection); device-related problems such as allergic reaction to metal or bending, breaking, or loosening of the device; and neurologic deficit due to stretching of the spinal cord because of expansion. The crankshaft phenomenon is a complication following isolated posterior fusion surgeries in which the unfused anterior vertebral bodies continue to grow and cause lordosis and scoliosis. Crankshaft phenomenon is seen when the spine is skeletally immature and happens phenomenally during the 2 peak growth velocity periods (ie, from 0-5 years of age and from 10-15 years of age).²³

• Paralysis: Paralysis is the most feared complication of surgery for scoliosis. A survey conducted by the Scoliosis Research Society determined that the incidence of acute neurologic complications resulting from the treatment of scoliosis to be 0.72%.²⁴ In infantile scoliosis, because neural axis involvement is significant, the risk of neurologic injury is greater if not recognized preoperatively.
• Infection: Infection is a risk with all surgical procedures; antibiotic prophylaxis is essential.
• Pseudoarthrosis: Pseudoarthrosis is a failure of the spine to fuse and is more common in adults than in adolescents.
• Decompensation: Decompensation occurs because of overcorrection of the spinal curve, in which the curvature of the spine loses its flexibility, causing the patient to lean to one side.
• Flat-back syndrome: Flat-back syndrome is seen less often now because of technical improvements since the Harrington rod. In this condition, patients have decreased lumbar lordosis and need to hyperextend their hips to stand or need to adopt a flexed-hip-and-knee gait, leading to increased back fatigue.
• Low-back pain: There is a risk of low-back pain, especially after lower distal level fusion. This may result from unfused levels of the spine or degeneration of the fused spine.

OUTCOME AND PROGNOSIS

Section 8 of 10  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Multimedia
• References

More favorable outcomes have been associated with male sex, a left-sided curve, a low initial curve measurement, an RVAD of less than 20° in the initial radiograph, and the onset of scoliosis in the first year of life.

MULTIMEDIA

Section 9 of 10  

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Multimedia
• References

Media file 1:  RVAD (rib-vertebral angle difference) measurement at apical vertebra: RVAD = b-a (concave - convex side).
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Media file 2:  Preoperative scoliogram showing the Cobb angle.
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Media file 3:  Postoperative scoliogram after correction with the pediatric Isola system.
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Media type:  X-RAY

Media file 4:  Preoperative and postoperative radiographs show an increase in the space available for lung (SAL) after correction of scoliosis by VEPTR (vertical expandable prosthetic titanium rib).
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Media type:  X-RAY

Media file 5:  Preoperative and postoperative radiographs show an increase in the space available for lung (SAL) after correction of scoliosis by VEPTR (vertical expandable prosthetic titanium rib).
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Media type:  X-RAY

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Indications
• RELEVANT ANATOMY
• Workup
• Treatment
• Complications
• Outcome And Prognosis
• Multimedia
• References

1. Harrenstein RJ. Die Skoliose bei Sauglingen und ihre Behandlung. Z Orthop Chir. 1930;52:1-40.
2. Kumar K. Spinal deformity and axial traction. Spine. Mar 1 1996;21(5):653-5. [Medline].
3. James JI. Two curve patterns in idiopathic structural scoliosis. J Bone Joint Surg [Br]. 1951;33-B:399-406. [Medline].
4. Browne D. Congenital postural scoliosis. Br Med J. Sep 4 1965;5461:565-6. [Medline].
5. Dunn PM. Congenital postural scoliosis. Arch Dis Child. Aug 1973;48(8):654. [Medline].
6. Wynne-Davies R. Familial (idiopathic) scoliosis. A family survey. J Bone Joint Surg Br. Feb 1968;50(1):24-30. [Medline].
7. Lincoln TL. Infantile idiopathic scoliosis. Am J Orthop. Nov 2007;36(11):586-90. [Medline].
8. McMaster MJ. Infantile idiopathic scoliosis: can it be prevented?. J Bone Joint Surg Br. Nov 1983;65(5):612-7. [Medline].
9. Wynne-Davies R. Infantile idiopathic scoliosis. Causative factors, particularly in the first six months of life. J Bone Joint Surg Br. May 1975;57(2):138-41. [Medline].
10. Mehta MH. The rib-vertebra angle in the early diagnosis between resolving and progressive infantile scoliosis. J Bone Joint Surg Br. May 1972;54(2):230-43. [Medline].
11. Mehta MH. Growth as a corrective force in the early treatment of progressive infantile scoliosis. J Bone Joint Surg Br. 2005;87(9):1237-1247. [Medline].
12. Jarvis J, Garbedian S, Swamy G. Juvenile idiopathic scoliosis: the effectiveness of part-time bracing. Spine. May 1 2008;33(10):1074-8. [Medline].
13. Grivas TB, Burwell GR, Vasiliadis ES, Webb JK. A segmental radiological study of the spine and rib--cage in children with progressive infantile idiopathic scoliosis. Scoliosis. Oct 18 2006;1:17. [Medline].
14. Gstoettner M, Sekyra K, Walochnik N, Winter P, Wachter R, Bach CM. Inter- and intraobserver reliability assessment of the Cobb angle: manual versus digital measurement tools. Eur Spine J. Oct 2007;16(10):1587-92. [Medline].
15. Alotaibi S, Harder J, Spier S. Bronchial obstruction secondary to idiopathic scoliosis in a child: a case report. J Med Case Reports. May 22 2008;2:171. [Medline].
16. Akbarnia BA., Marks DS, Boachie-Adjei O, et al. Dual growing rod technique for the treatment of progressive early-onset scoliosis: a multicenter study. Spine. 2005;30(17 Suppl):S46-57. [Medline].
17. Bridwell KH. Spinal instrumentation in the management of adolescent scoliosis. Clin Orthop Relat Res. Feb 1997;64-72. [Medline].
18. Cotrel Y, Dubousset J. A new technic for segmental spinal osteosynthesis using the posterior approach [in French]. Rev Chir Orthop Reparatrice Appar Mot. 1984;70(6):489-94. [Medline].
19. Dwyer AF, Newton NC, Sherwood AA. An anterior approach to scoliosis. A preliminary report. Clin Orthop Relat Res. Jan-Feb 1969;62:192-202. [Medline].
20. Harrington PR. Treatment of scoliosis: correction and internal fixation by spine instrumentation. June 1962. J Bone Joint Surg Am. Feb 2002;84-A(2):316. [Medline].
21. Motoyama EK, Deeney VF, Fine GF, et al. Effects on lung function of multiple expansion thoracoplasty in children with thoracic insufficiency syndrome: a longitudinal study. Spine. 2006;31(3):284-90. [Medline].
22. Asher M, Lai SM, Burton D, Manna B, Cooper A. Safety and efficacy of Isola instrumentation and arthrodesis for adolescent idiopathic scoliosis: two- to 12-year follow-up. Spine. Sep 15 2004;29(18):2013-23. [Medline].
23. Kesling KL, Lonstein JE, Denis F, Perra JH, Schwender JD, Transfeldt EE, et al. The crankshaft phenomenon after posterior spinal arthrodesis for congenital scoliosis: a review of 54 patients. Spine. Feb 1 2003;28(3):267-71. [Medline].
24. MacEwen GD, Bunnell WP, Sriram K. Acute neurological complications in the treatment of scoliosis. A report of the Scoliosis Research Society. J Bone Joint Surg Am. 1975;57(3):404-408. [Medline].
25. Hoppenfeld S, Gross A, Andrews C, Lonner B. The ankle clonus test for assessment of the integrity of the spinal cord during operations for scoliosis. J Bone Joint Surg Am. 1997;79(2):208-12. [Medline].
26. Mau H. The changing concept of infantile scoliosis. Int Orthop. 1981;5(2):131-7. [Medline].

Article Last Updated: Jun 30, 2008