INFANTILE SCOLIOSIS

Questions and Answers

Differences from Juvenile and Pediatric Scoliosis

While infantile, juvenile, and adolescent scoliosis all involve spinal curvature, their differences are significant:

1. Age of Onset:
   • Infantile: Birth to 3 years.
   • Juvenile: 4 to 10 years.
   • Pediatric (General): This encompasses all cases from birth to 18 years, including infantile, juvenile, and adolescent forms.
2. Gender Distribution:
   • Infantile: More common in males.
   • Juvenile: Roughly equal or slight female predominance.
   • Adolescent (Pediatric): Predominantly female (up to 80% in idiopathic cases).
3. Etiology:
   • Infantile: Often idiopathic (infantile idiopathic scoliosis, IIS) but sometimes associated with congenital anomalies, neuromuscular conditions, or syndromes.
   • Juvenile: Frequently idiopathic, with a higher risk of progression than infantile cases.
   • Adolescent: Mostly idiopathic, rarely congenital or neuromuscular.
4. Curve Characteristics:
   • Infantile: Curves are typically left-sided (thoracic or thoracolumbar) and may spontaneously resolve in some cases.
   • Juvenile: Curves are often right-sided and progressive, requiring closer monitoring.
   • Adolescent: Right-sided thoracic curves are common, with progression tied to growth spurts.
5. Progression Risk:
   • Infantile: Variable; many resolve without intervention, but severe cases can progress rapidly due to early growth.
   • Juvenile: Higher likelihood of progression (up to 70%) due to longer growth periods ahead.
   • Adolescent: Progression depends on curve magnitude and skeletal maturity (e.g., Risser sign).
6. Associated Conditions:
   • Infantile: May accompany congenital defects (e.g., vertebral malformations) or syndromes (e.g., Marfan syndrome).
   • Juvenile: Less commonly congenital, but neuromuscular links (e.g., cerebral palsy) persist.
   • Adolescent: Rarely associated with underlying conditions in idiopathic cases.

Infantile scoliosis thus differs from juvenile and broader pediatric scoliosis in its early presentation, male predominance, and potential for spontaneous resolution, though severe cases share the progressive risks seen in older age groups.

Causes of Infantile Scoliosis

Infantile scoliosis arises from diverse origins, broadly classified as:

1. Idiopathic:
   • Infantile Idiopathic Scoliosis (IIS): No identifiable cause, though some theories suggest intrauterine positioning or postnatal molding (e.g., lying predominantly on one side). It’s more common in Europe than in the U.S. and often resolves spontaneously.
2. Congenital:
   • Results from vertebral malformations present at birth, such as hemivertebrae (half-formed vertebrae), fused vertebrae, or missing segments. These structural defects disrupt normal spinal alignment.
3. Neuromuscular:
   • Linked to conditions like cerebral palsy, muscular dystrophy, or spinal muscular atrophy, where muscle imbalances pull the spine out of alignment.
4. Syndromic:
   • Associated with genetic syndromes, such as Marfan syndrome, Ehlers-Danlos syndrome, or neurofibromatosis, which affect connective tissue or skeletal development.
5. Secondary:
   • Caused by external factors like tumors, infections, or trauma, though rare in infants.

Unlike juvenile scoliosis, which leans heavily toward idiopathic, infantile scoliosis has a higher proportion of congenital and syndromic cases due to its early onset during critical developmental stages.

Symptoms of Infantile Scoliosis

Symptoms in infants are subtle and often noticed by parents or pediatricians rather than reported by the child:

• Visible Curve: A lateral “C” or “S” shape in the spine, most apparent when the child is upright or lying down.
• Asymmetry: Uneven shoulders, hips, or rib cage (e.g., one side protruding more, known as a “rib hump”).
• Postural Issues: Head tilting to one side or difficulty sitting symmetrically.
• Plagiocephaly: Flat head syndrome, sometimes linked to positioning that also affects the spine.
• Respiratory Distress: In severe cases, a large curve can restrict lung development, causing breathing difficulties.
• Neurological Signs: Rarely, leg weakness or abnormal reflexes if nerves are compressed (e.g., in congenital cases).

Compared to juvenile scoliosis, infantile scoliosis symptoms are harder to detect due to limited mobility and verbal feedback, making regular checkups critical.

Diagnosis

Diagnosing infantile scoliosis involves a multi-step process:

1. Physical Examination:
   • Adams Forward Bend Test: The child bends forward (or is held in position), revealing spinal asymmetry or rib humps.
   • Postural Assessment: Checks for shoulder, hip, or head misalignment.
   • Neurological Exam: Tests reflexes and strength to rule out nerve involvement.
2. Imaging:
   • X-rays: Measure the Cobb angle (degree of curvature); a curve >10° confirms scoliosis. Low-dose techniques (e.g., EOS imaging) minimize radiation in infants.
   • MRI: Used if congenital, neuromuscular, or neurological issues are suspected to assess spinal cord or soft tissue abnormalities.
   • Ultrasound: Occasionally used in very young infants to avoid radiation, though less precise.
3. Classification:
   • Curves are labeled as resolving (likely to improve) or progressive (worsening) based on initial severity and follow-up X-rays.

Diagnosis in infants differs from juvenile cases due to the need for gentler handling, radiation concerns, and reliance on parental observation rather than patient-reported symptoms.

Non-Surgical Treatment

Most infantile scoliosis cases are managed conservatively, especially if idiopathic and mild:

1. Observation:
   • Indication: Curves <20° with no rapid progression.
   • Process: Regular monitoring (every 3-6 months) with X-rays to track the curve. Up to 90% of idiopathic infantile curves resolve spontaneously by age 3-5.
2. Casting:
   • Indication: Progressive curves (20°-40°) in children under 2.
   • Method: Mehta casting (or EDF—elongation, derotation, flexion) uses plaster casts applied under anesthesia to gently correct the spine over months. Casts are changed every 6-12 weeks.
   • Goal: Halt progression and encourage straight growth, leveraging the spine’s early plasticity.
3. Bracing:
   • Indication: Curves 20°-40° in children over 2 or after casting.
   • Method: Custom-made orthoses (e.g., Boston brace) worn 18-23 hours daily to stabilize the spine.
   • Difference from Juvenile: Bracing is less common in infants due to rapid growth and casting’s effectiveness, whereas it’s a mainstay for juvenile cases.

Physical therapy is less emphasized in infants than in juvenile scoliosis, as muscle strengthening is impractical at this age.

Surgical Treatment

Surgery is reserved for severe, progressive cases unresponsive to conservative measures:

1. Growing Rods:
   • Indication: Curves >50° threatening lung or heart function.
   • Method: Rods are attached to the spine and lengthened every 6 months (via surgery or magnetically controlled rods) to accommodate growth.
   • Goal: Control the curve until the child is old enough for definitive correction.
2. Vertebral Body Tethering (VBT):
   • Indication: Emerging option for flexible curves in slightly older infants or juveniles.
   • Method: A flexible cord tethers the convex side of the curve, guiding growth to straighten the spine.
   • Advantage: Preserves motion compared to fusion.
3. Spinal Fusion:
   • Indication: Rare in infants, used only in extreme congenital cases with no growth potential.
   • Method: Vertebrae are fused with rods and screws to permanently correct the curve.
   • Drawback: Limits spinal growth, avoided unless critical.

Surgery in infantile scoliosis prioritizes growth preservation (unlike juvenile or adolescent cases, where fusion is more common), reflecting the longer growth period ahead.

Prognosis

The prognosis for infantile scoliosis varies widely:

• Resolving Curves: In idiopathic cases with curves <20°, up to 90% improve without intervention by age 5, especially if diagnosed early and monitored.
• Progressive Curves: Untreated severe curves (>50°) can lead to thoracic insufficiency syndrome (impaired lung growth), chronic pain, or deformity. With treatment, doctors may stop the progression, though some residual curvature may persist.
• Congenital/Neuromuscular Cases: Poorer prognosis due to underlying conditions; doctors may recommend surgery with outcomes tied to the primary disorder.
• Compared to Juvenile, Infantile scoliosis has a higher spontaneous resolution rate but a greater risk of rapid worsening in early growth phases, while juvenile cases progress more predictably with puberty.

Long-term, successfully managed cases allow normal activity, though severe early interventions (e.g., fusion) may limit spinal flexibility or height.

For the Finest of Treatment

Infantile scoliosis refers to a unique form of pediatric scoliosis, distinguished by its onset before age 3, male predominance, and potential for spontaneous resolution. Unlike juvenile scoliosis, it balances a higher rate of congenital causes with a chance of natural correction, requiring careful diagnosis and tailored treatment. From observation and casting to advanced surgical techniques, management focuses on leveraging early growth while preventing complications like respiratory compromise. With vigilant care, most children with infantile scoliosis achieve favorable outcomes, highlighting the importance of early detection and expert intervention in shaping their spinal health.