summary Infantile Idiopathic Scoliosis is a coronal plane spinal deformity which most commonly presents in children ages 3 years or less. Diagnosis is made with full-length PA and lateral spine radiographs. MRI studies are indicated to rule out syrinx, tumor, or tethered cord. Treatment can be observation, bracing, or surgical management depending on the skeletal maturity of the patient, magnitude of deformity, and curve progression. Epidemiology Incidence 4% of idiopathic scoliosis cases Demographics males > females Anatomic location usually left thoracic Risk factors family history Etiology Pathophysiology pathoanatomy may adversely affect growth of alveoli and normal development of the thoracic cage Genetics autosomal dominant with variable penetrance Associated conditions plagiocephaly (skull flattening) congenital defects neural axis abnormalities 22% of patients with curves > 20° will be affected 80% of these patients will need neurosurgical involvement thoracic insufficiency syndrome characterized by decreased thoracic growth and lung volume leads to pulmonary hypertension and cor pulmonale pulmonary function impairment associated with curves > 60° cardiopulmonary issues associated with curves > 90° Anatomy Osteology the T1-L5 spinal segment grows fastest in the 1st five years of life the height of the thoracic spine increases by 2 times between birth and skeletal maturity Classification Infantile Idiopathic Scoliosis consists of resolving type progressive type Early onst scoliosis early-onset scoliosis is a broader category that includes scoliosis in children < 10 years. It includes infantile idiopathic scoliosis (this topic) juvenile idiopathic scoliosis congenital scoliosis neurogenic scoliosis syndromic scoliosis Marfan's Down's syndrome Presentation History age deformity was first noticed and any observed progression perinatal history developmental milestones Presentation most present with deformity excessive drooling may reflect neurologic condition Physical exam inspection cafe-au-lait spots (neurofibromatosis) patches of hair dimpling over the spinal region dimpling outside of the gluteal fold is usually benign nevi or other tumors may be indicative of spinal dysraphism plagiocephaly (skull flattening) neurologic motor document developmental milestones evaluate for cavovarus feet upper and lower extremities exam reflexes abnormal abdominal reflexes associated with the presence of a syrinx clonus Hoffman sign Babinski gait analysis Imaging Radiographs recommended views standing PA and lateral supine in infants unable to stand (will make curve appear less severe) findings look for congenital vertebral defects measurements cobb angle > 20 degrees associated with progression rib phase technique convex rib head position with respect to the apical vertebrae findings phase 1 - no rib overlap phase 2 - rib overlap with the apical vertebrae high risk for curve progression RVAD (rib vertebrae angle difference, Mehta angle) technique measure angle between the endplate and rib (line between midpoint of rib head and neck) RVAD = difference of 2 rib-vertebral angles findings > 20° is linked to high rate of progression < 20° is associated with spontaneous recovery MRI obtain MRI of spine first to rule out tether cyst tumor syrinx (20% incidence) Treatment Nonoperative observation alone (most resolve spontaneously) indications Cobb angle < 30° RVAD < 20° 90% will resolve spontaneously serial Mehta casting (derotational) or thoracolumbosacral orthosis (TLSO) indications flexible curves Cobb angle > 30° RVAD > 20° phase 2 rib-vertebrae relationship (rib-vertebral overlap) mechanism functions to straighten the spine in young patients in older patients it serves as an adjunctive measure prior to definitive treatment bracing indications incompletely corrected curves after Mehta casting late presenting cases where the spine is still flexible Operative growing rod construct (dual rod or VEPTR) indications Cobb > 50 to 60 degrees failed Mehta casting or bracing fusion delay until as close to skeletal maturity as possible fusion before age 10 years results in pulmonary compromise outcomes improvement in FVC pulmonary function with implementation of growing construct Techniques Growing rod construct (dual rod or VEPTR) permits growth of affected part of spine up to 5 cm dual rods or VEPTR use anchors proximally and distally serial lengthening required every six to eight months Complications High rate of complications with surgical treatment Prognosis Progression most resolve spontaneously if progressive by age 5, >50% of children will have a curve > 70° Mehta predictors of progression Cobb angle > 20° RVAD > 20° phase 2 rib-vertebral relationship (rib-vertebral overlap) Prognosis progressive curves have poor outcomes and must be treated can be fatal if not treated appropriately