Infantile and Juvenile Scoliosis

Etiology

By definition, early-onset scoliosis occurs before the age of 10 and is host to a heterogeneous spectrum of causes. This includes congenital scoliosis, structural scoliosis, neuromuscular scoliosis, syndromic scoliosis, and idiopathic scoliosis.[3][4] Infantile scoliosis, by nomenclature, includes those patients younger than the age of 3 at the time of presentation. Juvenile scoliosis includes those from ages 3 to 10.

Epidemiology

Early-onset scoliosis, from all causes, accounts for approximately 10% of all pediatric scoliosis cases.

Pathophysiology

Congenital scoliosis results from a congenital disability in vertebral formation and segmentation.

Structural scoliosis results from a resulting body problem such as fused ribs, diaphragmatic hernia, or chest wall abnormalities.

Neuromuscular scoliosis is driven by neuromuscular disorders such as cerebral palsy or muscular dystrophy.

Syndromic scoliosis is associated with VACTERL (vertebral, anal atresia, cardiac defects, tracheoesophageal fistula, renal abnormalities, and limb defects) and neurofibromatosis.

History and Physical

Patients will present with obvious spinal deformity with or without a known syndromic pathology. It is important to recognize that the initial presentation of a syndrome may be a spinal abnormality. Complete pediatric history including birth history should be gathered. Physical examination should include a full neurologic assessment as well as a photographic assessment of the spinal deformity. Furthermore, the patient’s spinal flexibility should be examined clinically on the examination table (when possible) to determine the relative rigidity of the spinal column.

Evaluation

A thorough evaluation of interprofessional teams is mandatory. This should include a complete workup of the patient’s overall medical and social status.[5][6]

Imaging

X-rays are the main imaging modality that allows the surgeon to trend deformity and measure angular deformity.

Early-onset scoliosis (EOS) imaging allows the clinician to understand the three-dimensional nature of the deformity with ultra-low dose radiation pulse in a standing or upright position

CT with a substantial radiation burden, this modality allows for fine detail of the bony vertebral anatomy and ribs

MRI uses magnetic imaging to determine abnormalities of the spinal cord. It can detect common co-presentations such as a Chiari, a syrinx, or tethered cord.

Treatment / Management

General treatment and management aim to halt the progression of the spinal deformity. The goal is to increase thoracic volume to improve pulmonary and cardiac function.

Spinal bracing is largely ineffective in this population and is poorly tolerated.

Prior to any intervention-based treatment, the patient’s health and functional status should be optimized.[7][8][7](B3)

Surgical Options

Traditional growing rods can be inserted to allow for initial placement of proximal and distal anchors (hooks or pedicle screws). The rod can be lengthened with a smaller surgery at planned intervals. This is an effective modality, but risks include anchor pull out, the need for repetitive surgery, and infection.[9][10](B2)

Magnetic growing rods are an innovative technology that undergoes a similar placement of proximal and distal anchors (hooks or pedicle) screws. However, the rod is elongated via magnetic control. Patients generally need to be at least 2 years old and 25 pounds. Consideration must also be entertained for the need of possible MRI study in the future.

Vertical, expandable, prosthetic, titanium, rib-expansion thoracoplasty can be used in patients with thoracic insufficiency syndrome. This places instrumentation on the ribs as well as spinal constructs to expand the thorax and reduce the spinal deformity.

Growth-guided techniques (Shilla procedure) involves the placement of a pedicle screw into the rigid apical vertebrae (the worst portion of the deformity) while other more proximal and distal pedicle screws have a locking cap mechanism that allows the longitudinal movement of the rod during growth into a fixed pedicle screw to guide alignment. Due to the biomechanical forces, rod-breakage is an expected outcome with 4.5 mm rods generally lasting about 4 to 6 years.

New emerging techniques and technologies are currently under evaluation.

Differential Diagnosis

• Ankylosing spondylitis

• Aneurysmal bone cyst

• Hemangioma

• Juvenile idiopathic arthritis

• Osteoid osteoma

• Osteoblastoma

Staging

Classification for nomenclature purposes has been established by Williams et al. with the collaboration of the Children’s Spine Study Group and the Growing Spine Study Group. This classification system has been seen with interobserver and intraobserver reliability.

The C-EOS

Patient age

Etiology

• Congenital/Structural (C)
• Neuromuscular (M)
• Syndromic (S)
• Idiopathic (I)

Coronal Cobb angle

• Less than 20 degrees (1)
• 20 to 50 degrees (2)
• 51 to 90 degrees (3)
• Greater than 90 degrees (4)

Maximum kyphosis

• Less than 20 degrees (-)
• 20 to 50 degrees (N)
• Greater than 50 degrees (+)

Progression modifier

• Less than 10 degrees per year (P0)
• 10 to 20 degrees per year (P1)
• Greater than 20 degrees per year (P2)

For example, a 7-year-old patient with congenital scoliosis with a 23-degree coronal curve having 57 degrees of kyphosis with 15 degrees of progression would be labeled a 7C2+P1.

Prognosis

Early-onset scoliosis is a heterogeneous constellation of diseases. Prognosis is linked largely to the co-morbidities and deformity at the time of presentation. This can be linked to the syndromic nature of the presentation, or more importantly, to the curve’s impact on thoracic growth and function.

During the first 2 years, lung development is significant. By year 8, alveolar maturation will level off. Those with limited thoracic function due to scoliosis development can see alveolar hypoplasia, abnormal ventilation, and decreased lung compliance. Cardiac issues such as cor pulmonale and pulmonary hypertension can also present. The inability of the thoracic to appropriately lung growth and function are known as thoracic insufficiency syndrome. 

Prognosis of the deformity is related heavily to the skeletal maturity of the patient as well as a degree of deformity. Thoracic to sacral spine grows at approximately 2 cm per year for the first 5 years of life and then 1 cm per year from ages 5 to 10 with 1.8 cm per year until maturity. Rapid growth is seen in the first 5 years and then during the adolescent phase.

The rib-vertebral angle  (RVAD) at the apical vertebrae is prognostic for the progression of early-onset scoliosis from idiopathic conditions. An RVAD of greater than 20 degrees an initial presentation is more likely to progress.

Complications

Those patients with untreated early-onset scoliosis over the age of 40 have a 50% increase in mortality. Furthermore, those with a curve of greater than 70 degrees equally showed increased mortality.