summery

• Congenital Scoliosis is a congenital spinal deformity that occurs due to the failure of normal vertebral development during 4th to 6th week of gestation.

• Diagnosis is made with AP and lateral full spine radiographs. MRI is required to assess for neural axis abnormalities. 

• Treatment can be observation or surgical management depending on the specific anatomical anomaly, and curve progression.

Etiology

• Mechanism

  • caused by a developmental defect in the formation of the mesenchymal anlage

• Causes

  • most cases occur spontaneously 

     

  • maternal exposures

    • diabetes

    • alcohol

    • valproic acid

    • hyperthermia

• Genetic

  • uncertain

• Associated conditions 

   

  • may occur in isolation or with associated conditions

  • with associated systemic anomalies, up to 61%

    • cardiac defects - 10%

    • genitourinary defects - 25%

    • spinal cord malformations

  • with underlying syndrome or chromosomal abnormality

    • VACTERL syndrome

      • in 38% to 55%

      • characterized by vertebral malformations, anal atresia, cardiac malformations, tracheo-esophageal fistula, renal, and radial anomalies, and limb defects

    • Goldenhar/OculoAuricularVertebral Syndrome

      • hemifacial microsomia and epibulbar dermoids

    • Jarcho-Levin Syndrome/Spondylocostal dysostosis

      • short trunk dwarfism, multiple vertebral and rib defects and fusion

      • most commonly autosomal recessive

      • often associated with thoracic insufficiency syndrome (TIS)

        • caused by shortening of the thorax and rib fusions

        • result is thorax is unable to support lung growth and respiratory decompensation

    • Klippel-Feil syndrome

      • short neck, low posterior hairline, and fusion of cervical vertebrae

    • Alagille syndrome

      • peripheral pulmonic stenosis, cholestasis, facial dysmorphism

classification

• • Failure of Formation	Fully segmented hemivertebra -has normal disc space above and below
    	Semisegmented hemivertebra -hemivertebra fused to adjacent vertebra on one side with disk on the other
    	Unsegmented hemivertebra -hemivertebra fused to vertebra on each side
    	Incarcerated hemivertebra -found within lateral margins of the vertebra above and below
    	Unincarcerated hemivertebra -laterally positioned
    	Wedge vertebra
    Failure of Segmentation	Block vertebra (bilateral bony bars)
    	Bar body (unilateral unsegmented bar is common and likely to progress)
    Mixed	Unilateral unsegmented bar with contralateral hemivertebra (most rapid progression)

Imaging

• Radiographs

  • recommended views

    • AP and lateral plain films usually sufficient to confirm diagnosis

• CT

  • indications

    • judicious use recommended due to radiation exposure

    • 3D CT useful to better delineate posterior bony anatomy and define type for surgical planning

• MRI

  • indications

    • all patients with congenital scoliosis prior to surgery to evaluate for neural axis abnormality (found in 20-40%) including

      • Chiari malformation

      • tethered cord

      • syringomyelia

      • diastematomyelia

      • intradural lipoma

  • technique

    • sedation required in infants so may be delayed if no surgery is planned and no neuro deficits

• Additional medical studies

  • important to obtain studies for associated abnormalities 

     

    • renal ultrasound or MRI

    • echocardiogram if suspicion for cardiac manifestations

Treatment

• Nonoperative

  • observation and bracing

    • indications for observation

      • absence of documented progression, ie:

        • incarcerated hemivertebrae

        • nonsegmental hemivertebrae

        • some partially segmented hemivertebrae

    • bracing

      • not indicated in primary treatment of congenital scoliosis (no effectiveness shown)

      • may be used to control supple compensatory curves, but effectiveness is unproven

• Operative

  • posterior fusion (+/- osteotomies and modest correction)

    • indications

      • hemi-vertebrae opposite a unlateral bar that does not require a vertebrectomy at any age. this otherwise will relentlessly progress until fused.

      • older patients with significant progression, neurologic deficits, or declining respiratory function

      • having many pedicle screws may decrease crankshaft phenomenon adn obviate the need for an anterior fusion.

  • anterior/posterior spinal fusion +/- vertebrectomy

    • indications

      • young patients with significant progression, neurologic deficits, or declining respiratory function

        • girls < 10 yrs

        • boys < 12 yrs

      • patients with failure of formation with contralateral failure of segmentation at any age that requires hemi-vertebrectomy and/or significant correction. This may be done from a posterior approach 

         

    • technique

      • nutritional status of patient must be optimized prior to surgery

  • distraction based growing rod construct

    • indications

      • may be used in an attempt to control deformity during spinal growth and delay arthrodesis

    • outcomes

      • need to be lengthened approximately every 6 months for best results

  • osteotomies between ribs 

    • indications

      • mulitple (>4) fused ribs wit potential for thoracic insufficiency syndrome

    • outcomes

      • long-term follow up is needed to determine efficacy. the downside is this may make the chest stiff and hurt pulmonary function.

  • Hemi-Vertebrectomy - usally done from a posterior approach, particularly with kyphosis.

    • indications - age 3-8 years (younger is difficult to get good anchor purchase)

    • progressive or significant deformity 

Teqniques

• Spinal arthrodesis +/- vertebrectomy/osteotomy

  • in situ arthrodesis, anterior/posterior or posterior alone

    • indications

      • unilateral unsegmented bars with minimal deformity

  • hemiepiphysiodesis

    • indications

      • intact growth plates on the concave side of the deformity

      • patients less than 5 yrs. with < 40-50 degree curve

      • mixed results

  • osteotomy

    • osteotomy of bar

  • hemivertebrectomy

    • hemivertebrae with progressive curve causing truncal imbalance and oblique takeoff

      • often caused by a lumbosacral hemivertebrae

    • patients < 6 yrs. and flexible curve < 40 degrees best candidates

  • spinal column shortening resection

    • indications

      • deformities that present late and have severe decompensation

      • rigid, severe deformities

      • pelvic obliquity, fixed

Complication

• Crankshaft phenomenon

  • a deformity caused by performing posterior fusion alone

• Short stature

  • growth of spinal column is affected by fusion

    • younger patients affected more

• Neurologic injury

  • surgical risk factors include

    • overdistraction or shortening

    • overcorrection

    • harvesting of segmental vessels

  • somatosensory and motor evoked potentials important

• Soft-tissue compromise

  • nutritional aspects of care essential to ensure adequate soft tissue healing

Prognosis

• Dependent on potential for progression and early intervention

• Progression 

    

  • most rapid in the first 3 years of life

  • anterior failure of formation is rapidly progressive and often results in paralysis; anterior failure of segmentation can be rapidly progressive but rarely results in paralysis

  • determined by the morphology of vertebrae. Rate of progression from greatest to least is:

    • unilateral unsegmented bar with contralateral hemivertebra >

      • greatest potential for rapid progression (5 to10 degrees/year)

    • unilateral unsegmented bar >

    • fully segmented hemivertebra >

    • unincarcerated hemivertebra >

    • incarcerated hemivertebra >

    • unsegmented hemivertebra >

    • block vertebrae

      • little chance for progression (<2 degrees/year)

  • presence of fused ribs increases risk of progression