Modern Study Review (AI-Generated)
High-Yield Summary
Adolescent Idiopathic Scoliosis (AIS) is the most common spinal deformity in children over 10 years old, characterized by a lateral curvature of the spine with vertebral rotation. Early identification and risk stratification for curve progression are critical to guide treatment and optimize long-term pain and function outcomes. Modern management balances non-operative bracing for moderate curves with surgical correction for progressive or severe deformities, aiming to prevent deformity progression and preserve spinal mobility.
Key Diagnostic Findings
Anatomy
- Curve Types: Thoracic, lumbar, or thoracolumbar curves, often with vertebral rotation and sagittal plane abnormalities.
- Vertebral Landmarks: End vertebrae, stable vertebra (aligned with center sacral line), apical vertebra (most rotated/tilted).
Clinical Presentation
- Typically asymptomatic in early stages; detected by screening or cosmetic concerns (rib hump, asymmetry).
- Risk factors for progression include younger age at diagnosis, premenarchal status, female sex, and skeletal immaturity (low Risser grade).
Imaging
- Standing PA and lateral spine radiographs are standard.
- Risser Sign: Assesses skeletal maturity (0–5 scale).
- Cobb Angle: Measures curve magnitude; >10° defines scoliosis.
- Side-bending films: Assess curve flexibility.
- MRI indicated if atypical features or neurological signs present.
Classification Systems
| Classification | Description | Clinical Use |
|---|---|---|
| King Classification | Five curve types based on curve pattern and stiffness; historically used for surgical planning. | Largely replaced by Lenke classification but still referenced. |
| Lenke Classification (Modern Standard) | Incorporates curve type, lumbar modifier, and sagittal thoracic modifier for comprehensive surgical planning. | Current gold standard for AIS classification. |
Current Gold Standard Treatment
Non-operative
- Indications: Curves 25°–45° in skeletally immature patients (Risser 0–2).
- Treatment: Rigid thoracolumbosacral orthosis (TLSO) bracing, worn 16–23 hours/day until skeletal maturity.
- Goal: Prevent curve progression and avoid surgery.
Operative
- Indications: Curves >45°–50°, progression despite bracing, or severe deformity causing pain or functional impairment.
- Procedure: Posterior spinal fusion with segmental pedicle screw instrumentation is the current gold standard.
- Principles: Fusion from end vertebrae to stable vertebra to prevent junctional kyphosis; correction of coronal and sagittal deformity; preservation of lumbar motion segments when possible.
Modern Complications & Outcomes
Complications
| Complication | Description | Incidence/Notes |
|---|---|---|
| Infection | Surgical site infection, typically managed with antibiotics or debridement. | ~1–3% |
| Neurologic Injury | Rare but serious; intraoperative neuromonitoring reduces risk. | <1% |
| Implant Failure | Rod breakage or screw loosening, more common in poor bone quality. | <5% |
| Junctional Kyphosis | Kyphotic deformity at fusion ends; prevented by appropriate fusion levels. | Variable |
| Pulmonary Complications | Rare with modern techniques, more common in thoracic fusions. | <2% |
Outcomes
- Pain and Function: Most patients achieve pain relief and improved function post-treatment.
- Cosmetic Improvement: Significant correction of deformity improves quality of life.
- Long-Term: Fusion preserves spinal stability but may reduce flexibility; adjacent segment degeneration is a concern but uncommon in adolescence.
Classic Clinical Notes
Scoli-Idiopathic Adolescent (>10)
Approach to Adolescent Idiopathic Scoliosis
Curve Progression – 4 Growth Factors, 2 Curve Factors
- The younger the patient at diagnosis, the higher the risk of progression
- Presentation prior to menarche portends a higher risk of progression
- The lower the Risser grade at curve detection, the higher the risk of progression
- Females with comparable curves to males have 10 times the risk of progression
- Double curves have a greater tendency to progress than single
- The larger the curve at detection, the higher the risk of progression
Risser Grade versus Curve Magnitude: (The classic Lonstein natural history paper)
- If you are Risser 0-1, a curve >50°, lumbar curves >30° (we tend to worry more about lumbar curves >50°)
- Decompensation, rotation, apical deviation
- Single or multiple curves
- Proximity to skeletal maturity and progression despite bracing
King Classification
- I – S shaped curve, lumbar curve is larger and stiffer than thoracic curve; both cross midline
- II – S shaped curve, thoracic curve is larger and stiffer than lumbar curve; both cross midline
- III – Single thoracic curve, no compensatory lumbar curve; may be a small lumbar curve that does not cross midline
- IV – Long thoracolumbar curve in which L4 tilts into the curve
- V – Double thoracic curve – the upper curve is structural as seen on side bending
Surgical Rules
- Instrumentation should include end vertebrae
- Fusion should end at the stable vertebra – lying within the center sacral line
- Watch out for junctional kyphosis between a thoracic and lumbar curve – if present, must include the lumbar curve
Last Updated on January 25, 2026 by orthonet
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