What are the treatment options for a patient with adolescent idiopathic scoliosis?

Treatment Options for Adolescent Idiopathic Scoliosis

The treatment approach for adolescent idiopathic scoliosis is determined by curve magnitude, skeletal maturity (Risser stage), and risk of progression, with observation for curves <20°, bracing for curves 20-45° in skeletally immature patients, and surgery for curves >45-50°. 1

Initial Diagnostic Imaging

• Obtain standing posteroanterior and lateral radiographs of the complete spine as the initial imaging study for adolescent idiopathic scoliosis when no risk factors are present. 2
• Measure the Cobb angle on these radiographs to determine curve magnitude, which drives all subsequent treatment decisions. 3
• MRI of the complete spine is NOT routinely indicated for typical adolescent idiopathic scoliosis without risk factors. 2

Observation (Curves <20 Degrees)

For skeletally immature patients with curves under 20 degrees, observation alone is appropriate since progression risk is less than 30%. 1

• Obtain follow-up radiographs every 12 months for patients at Risser stages 0-3. 1
• Extend radiographic intervals to every 18 months for patients at Risser stages 4-5. 1
• Do not assume curves are stable simply because the patient is asymptomatic—curves can progress silently, particularly in skeletally immature patients. 4

Bracing (Curves 20-45 Degrees in Skeletally Immature Patients)

Bracing is the standard treatment for skeletally immature patients with curves between 20-45 degrees and aims to prevent progression to surgical thresholds. 5, 6

Indications for Bracing

• Curves measuring 20-45 degrees in patients with Risser stage 0-2 (significant remaining growth). 1, 5
• The likelihood of progression exceeds 70% in skeletally immature individuals with curves >20 degrees, making bracing critical. 1

Critical Success Factor: Compliance

• Bracing only prevents surgery when patients are highly compliant with brace wear—the number needed to treat is 3 highly compliant patients to prevent one surgery. 7
• Noncompliant bracing provides no benefit and represents overtreatment. 7
• Use heat sensors in braces to objectively monitor compliance rather than relying on patient self-report. 7

Bracing Protocol

• The Boston brace is the most commonly prescribed orthosis for adolescent idiopathic scoliosis. 7
• Personalized brace construction using 3D printing technology is increasingly utilized to improve fit and compliance. 8
• Continue bracing until skeletal maturity (Risser 4-5) is achieved. 6

Surgical Intervention (Curves >45-50 Degrees)

Surgery is indicated when curves exceed 45-50 degrees in skeletally immature patients or when curves exceed 50 degrees in skeletally mature patients due to continued progression risk of approximately 1 degree per year. 1, 3

Surgical Thresholds

• Curves >40-50 degrees with remaining growth potential warrant surgery to prevent further progression. 1
• Curves >50 degrees in skeletally mature patients require surgical intervention since thoracic curves may continue progressing at 1 degree per year even after skeletal maturity. 1, 3
• Documented curve progression despite skeletal maturity is an indication for surgery. 1, 3

Pre-Surgical MRI Evaluation

Obtain MRI of the complete spine before surgery if ANY of the following risk factors are present: 1, 3

• Left thoracic curve pattern (atypical for idiopathic scoliosis). 1
• Short segment curve. 1
• Absence of apical segment lordosis (hyperkyphosis). 2
• Rapid curve progression (>1 degree per month). 2
• Functionally disruptive pain. 2
• Focal neurological findings. 2
• Male sex (less common in idiopathic scoliosis). 2

Do not skip MRI evaluation when risk factors are present—up to 2-4% of adolescent idiopathic scoliosis patients have neural axis abnormalities that alter surgical planning. 1

Surgical Technique

• Posterior spinal fusion with instrumentation is the standard surgical approach for curves exceeding surgical thresholds. 1, 8
• Both allograft and autograft bone grafting are medically necessary to achieve solid arthrodesis. 1, 3
• Anterior vertebral body tethering (VBT) is a newer growth-modulating technique showing promising early results but remains investigational with limited use. 8

Special Considerations for Late-Stage Skeletal Growth (Risser IV-V)

Even at Risser stage IV-V with curves between 40-50 degrees, 39% of patients experience significant curve progression, and 25% progress to surgical thresholds. 9

• Younger age and Risser stage IV (versus V) are significant risk factors for progression in this population. 9
• Larger baseline curve magnitude (closer to 50 degrees) increases risk of reaching surgical thresholds. 9
• The annual progression rate averages 0.35 degrees in this population, but individual variation is substantial. 9
• Continue monitoring these patients every 12-18 months even after skeletal maturity is achieved. 1, 9

Common Pitfalls to Avoid

• Never assume skeletal maturity eliminates progression risk—thoracic curves >50 degrees continue progressing at approximately 1 degree per year after skeletal maturity. 1, 3
• Do not prescribe bracing for curves >45 degrees in skeletally immature patients—these curves require surgery, not bracing. 5
• Avoid excessive radiation exposure by adhering to recommended radiographic intervals (every 12 months for Risser 0-3, every 18 months for Risser 4-5). 1, 4
• Do not rely on patient-reported brace wear compliance—use objective heat sensor data. 7
• Never proceed to surgery without MRI evaluation when risk factors for neural axis abnormalities are present. 1, 3