Infantile Scoliosis (0-3)

Modern Study Review (AI-Generated)

High-Yield Summary

Infantile idiopathic scoliosis (IIS), presenting before age 3, is a distinct clinical entity with unique natural history and management challenges. Early-onset scoliosis (EOS), including IIS, carries a significant risk of cardiopulmonary compromise if thoracic deformity progresses before age 5. Accurate early diagnosis and risk stratification using clinical and radiographic parameters such as the Rib Vertebral Angle Difference (RVAD) guide treatment decisions, which range from observation to serial casting and, if necessary, growth-friendly surgical interventions.

Key Diagnostic Findings

Anatomy

• Age group: 0–3 years (infantile); early-onset scoliosis includes deformities before age 5.
• Curve characteristics:
• More common in males (unlike adolescent idiopathic scoliosis).
• Approximately 75% of curves convex to the left (contrast with adolescent idiopathic scoliosis, which is predominantly right convex).
• Thoracic and thoracolumbar curves may spontaneously resolve; double structural curves with thoracic involvement have higher progression risk.

Clinical Presentation

• Often detected incidentally or due to visible spinal deformity.
• May be associated with neurologic or congenital abnormalities; thorough evaluation is essential.
• Growth velocity is rapid in infancy, increasing risk of curve progression.

Imaging

• X-rays: Standing or sitting AP and lateral views to assess curve magnitude and vertebral anomalies.
• Rib Vertebral Angle Difference (RVAD):
• Measure the angle between the neck of the apical rib and vertical on both convex and concave sides.
• RVAD > 20° predicts curve progression with high sensitivity.
• MRI: Indicated if atypical features or suspicion for underlying pathology (e.g., tethered cord, syrinx, congenital anomalies).

Classification Systems

Current Gold Standard Treatment

Non-operative

• Observation: Most infantile curves spontaneously resolve, especially small, non-rotated curves.
• Serial Casting:
• Elongation-Derotation-Flexion (EDF) casting is the first-line conservative treatment for progressive curves (RVAD > 20°, large curves, or “floppy” infants).
• Casting is performed under general anesthesia in the operating room.
• Casting is most effective before age 5, correlating with rapid growth phase.
• Bracing: Limited role in infants; may be used after age 5 when growth velocity plateaus.

Operative

• Indicated for curves that progress despite serial casting or those with severe deformity threatening cardiopulmonary function.
• Modern surgical options include:
• Anterior discectomy over 4-5 apical segments to release the curve.
• Growth-friendly posterior instrumentation such as growing rods or magnetically controlled growing rods to allow spinal growth while controlling deformity.
• Surgery aims to balance deformity correction with preservation of spinal growth and pulmonary function.

Modern Complications & Outcomes

Complications

Outcomes

• Majority of infantile idiopathic curves resolve spontaneously without intervention.
• Serial casting has demonstrated high success rates in halting progression and avoiding surgery in many cases.
• Growth-friendly surgical techniques improve long-term pulmonary function and spinal growth compared to early spinal fusion.
• Early identification and treatment are critical to optimize pain-free function and cardiopulmonary health.

Classic Clinical Notes

Infantile Scoliosis (0-3 years)

Approach to Infantile Idiopathic Scoliosis

• Traditionally, idiopathic scoliosis has been divided into 3 categories based on age of onset:
• Infantile (0-3 years)
• Juvenile (4-9 years)
• Adolescent (10 years to maturity)
• Arguably, growth velocity is increased in infancy and adolescence but remains constant during the juvenile period, so it may not be worth assigning a category to juveniles. Thus, it may make more sense to conceptually break it down into two groups: early onset (deformity before age 5) and late onset (deformity after age 5).
• The key is that if significant thoracic deformity is present before age 5, the patient is at real risk of subsequent cardiopulmonary compromise.

Characteristics of “infantile” or “early onset” idiopathic scoliosis

• Males more commonly affected than females.
• Three quarters are convex to the LEFT, unlike adolescent idiopathics where the vast majority are convex right.
• Thoracic and thoracolumbar curves tend to resolve, but double structural curves with a thoracic component have definite progressive potential.
• Initial curve size and amount of associated rotation are prognostic factors.
• In general, most curves resolve spontaneously.

Mehta Rib Vertebral Angle Difference (RVAD) – a measure of rotation

• At the apical vertebra, measure the angle of the neck of the rib against vertical on both sides (on the convexity, the angle is more acute; on the concavity, the angle is more obtuse). The difference between these two angles is the RVAD.
• If the RVAD exceeds 20°, the curve is likely to be progressive.
• The RVAD greater than 20° is the single most important factor predicting progression.

Approach

• Start searching for other reasons for the deformity:
• Dysraphism?
• Tethered cord?
• Syrinx?
• Congenital failure of formation or segmentation.
• Look for other visceral abnormalities.
• X-rays to see if this is a congenital curve.
• Then measure the RVAD.
• If any suspicion that this is not an “idiopathic” curve, get an MRI!

Treatment

• Most resolve on their own.
• Serial casting (elongation derotation flexion casting) is the conservative treatment of choice.
• The indications for casting are unclear, but any low-weight floppy child with a big curve and an RVAD over 20 should be casted.
• Casting is usually done in the OR under general anesthesia.
• No point in casting past 5 years of age (growth velocity has plateaued). Can be braced after this.
• Surgery when serial casting has failed to halt progression – requires anterior discectomy over four or five apical segments, then growing rod posteriorly.

Last Updated on January 25, 2026 by orthonet