Congenital Scoliosis

Question 1

Congenital Scoliosis

Answer 1

Congenital scoliosis is the failure of normal vertebral development during 4th to 6th week of gestation

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

Question 2

Epidemiology

Answer 2

prevalence in general population estimated at 1% to 4%

Question 3

Causes

Answer 3

• most cases occur spontaneously
• maternal exposures
  
  • diabetes
  • alcohol
  • valproic acid
  • hyperthermia
• genetic
  
  • uncertain

Question 4

Associated conditions

Answer 4

• 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
  • Klippel-Feil syndrome

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

Question 5

Prognosis

Answer 5

• most rapid in the first 3 years of life
• 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

Question 6

Classification of Congenital Scoliosis

Answer 6

Question 7

Radiographs

Answer 7

• 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

Question 8

MRI Indications

Answer 8

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

Question 9

Additional medical studies

Answer 9

important to obtain studies for associated abnormalities

• renal ultrasound or MRI
• echocardiogram if suspicion for cardiac manifestations

Question 10

Nonoperative

Answer 10

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

Question 11

Operative

Answer 11

1. in situ arthrodesis, anterior/posterior or posterior alone
2. hemiepiphysiodesis
3. osteotomy
4. hemivertebrectomy
5. spinal column shortening resection

Question 12

operative treatment measures

Answer 12

• 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

Question 13

Complications

Answer 13

• 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