AIS 

Posted bythespinebookadminPosted inPediatrics and Scoliosis, Topics

Background 

  • Children 10 – 18 idiopathic 
  • 3% have minor, .3% serious (>30) 
  • 10:1 female 
  • R thoracic more common (wraps around the heart) 

Presentation 

  • Shoulder height 
  • Truncal shift 
  • Pelvis symmetrry 
  • Adams bend test – axial plane deformity (rib hump) means structural curve 
  • Midline skin defects (spinal dysraphism) 
  • Café au lait (NF) 
  • Foot deformity (cavovarus) – neural axial, warrants MRI 
  • Assymetric abdo reflexes (get MRI) 

Risk Factors for Curve Progression 

  • F>M 
  • Curve Magnitude 
    • Before maturity 
      • >25 progress and will require surgery 
    • After maturity 
      • >50 progress 1-2 per year 
  • Multiple methods to predict remaining skeletal growth 
    • Tanner Whitehouse III RUS (radius ulna select MCs) closest to curve acceleration phase 
    • Risser Sign – amount of calcification as a measure of maturity 
      • 0 – 2/3 pubertal growth spurt (greatest growth velocity) 
      • 1-5 (20% calcified each) 
    • Triradiates – open or closed 
    • Menarche – growth stops in 2 years 
    • Olecranon apophysis closure 

Imaging 

  • 3 foot standing AP and lateral 
  • Bending films  
  • MRI if 
    • Age <10 
    • Males 
    • Abnormal curve patter (L Thoracic) 
    • Rapid progression 
  • MRI identifies: Chiari malformation, syringomyelia 

Surgical Indication 

  • Cosmetic 
  • Curve >90 – CV dysfunction, early death, pain, decreased self image 
  • Acute and chronic pain in adult if untreated 

Lenke Classification 

Step 1: Coronal Curve Class 

A.) ID 3 levels 

  • PT T345 
  • MT T6-T11/12 IVD 
  • TL T12-L1 
  • L L1 or below 
  • *when the MT is very low, more likely to have a PT curve too (double thoracic) 

B.) At each, ID: 

  • Apex 
  • Ends 
  • Cobb angle 

C.) Name each curve 

  • Major – biggest curve 
  • Structural  
    • – does not bend out 25 degrees, there is actual dysmorphic vertebrae 
    • ROTATION is more important 
    • PT  
Number PT MT TL/L Eponym 
1  major  Main thoracic 
2 + major  Double thoracic 
3  major + Double major 
4 + major + Triple major 
5   major  
6  + major  

Step 2: Lumbar Modifier 

  • Find ALV 
    • Most rotated, least tilted 
  • CSVL upwards 
  • Where is ALV relative to CSVL 
    • A – between pedicles 
    • B – touches pedicle 
    • C – not touching ALV 

Step 3: Sagittal Modifier 

  • T5-T12 Cobb angle 
    • <10 hypoK 
    • 10-40 normoK 
    • >40 hyperK 
  • Stable for Sagittal – Draw line up from L5S1 back corner of disk –  

Nash-Moe 

  • Pedicle rotation 

Dr. Lewis Tips 

  • People overlook PT 
  • If it is level then there must be a curve 
    • Lenke has only an MT so the shoulders are usually not level 
    • If it is a Double Thoracic (or triple major) then nee to include T2 
  • Lenke does not consider translation or rotation 
  • Don’t stop at L2 ever it is like standing on the border 

Management 

  • Bracing – curve >25 during growth 
    • Apex >T7 Milwaukeeprefabricated 3 point 23h per day 
    • Apex <T7 Boston 
    • Dicontinue: >2 years post menarche or no evidence of height increase in 6 months 
    • NNT of 3 to prevent 1 surgery 
  • Surgery 
    • Thoracic Curve >50, Lumbar >45 
    • Goals 
      • Maintain coronal and sagittal alignment 
      • Level shoulders 
      • Correct deformity 
      • Preserve motion segments 
    • Approach – posterior 
    • Fusion levels  
      • T2 (with PT) or T4 
      • L – last stable vertebrae (one with thee CSVL touching the pedicle) 
    • IONM 

Complications 

  • Neurologic injuiry 
    • Increased risk with kyphosis, excessive correction, sublaminar wires 
  • Pseudoarthrosis (2%) 
    • Late pain, deformity progression 
  • Infection (2%) 
    • Late pain 
    • P Acne most common for delayed infection (2 weeks for culture incubation) 
  • Flat back syndrome 
    • Loss of lumbar stenosis 
    • Not so common witth segmental instrumentation (worse with growing rods etc) 
    • Management: Revision with PSIF and closing wedge 
  • Crankshaft 
    • Rotational due to continued anterior spinal groowth 
  • SMA Syndrome  
    • Superior Mesenteric Artery 
    • Compression of 3rd part of duodenum due to narrow space between SMA and Aorta 
    • Presentation: 
      • Bowel obstruction post op 
      • Electrolyte abnormalities 
      • NV, weight loss 
    • RF 
      • Sagittal kyphsis 
      • Low height and weight 
    • Management  
      • NG Tube 
      • IV Fluids 
  • HW failure 
    • Rod break likely pseudarthrosis 
  • SIADH 
    • Hyponatremic due to SIADH 
      • Oligouric, inc secretion of sodium 
    • Due to SC itself