What is the likely cause of mild spine curvature in a 17-year-old female with asthma, taking Budesonide (budesonide) and albuterol, who is active and plays tennis?

Adolescent Idiopathic Scoliosis

This 17-year-old active female tennis player has adolescent idiopathic scoliosis (AIS), the most common form of spinal curvature in this age group, affecting 2-4% of adolescents with a female predominance. 1, 2, 3

Diagnosis and Definition

• AIS is defined as a lateral spinal curvature greater than 10 degrees (Cobb angle) occurring between ages 10-18 years without identifiable cause. 1, 2, 3
• This is a diagnosis of exclusion—other causes of scoliosis (congenital, neuromuscular, syndrome-related, secondary) must be ruled out through history and examination. 2, 3
• The "mild" curvature noted incidentally is consistent with early-stage AIS, which often presents asymptomatically and is discovered during routine examination or sports physicals. 2, 3

Key Clinical Context

• At age 17, this patient is likely near skeletal maturity, which significantly impacts progression risk and treatment decisions. 1, 2
• Her active tennis participation is not causative but important for treatment planning—specific sports like tennis involve rotational forces that should be considered. 4
• The asthma medications (budesonide and albuterol) are relevant because inhaled corticosteroids can affect bone mineral density and growth velocity, though effects are typically small and nonprogressive at low-to-medium doses. 4

Immediate Assessment Requirements

Obtain standing posteroanterior and lateral radiographs of the complete spine to measure the Cobb angle and assess skeletal maturity (Risser sign). 1, 2, 3

Key radiographic parameters to evaluate:

• Cobb angle measurement determines treatment pathway: <20° = observation, 20-45° = potential bracing (if immature), >45-50° = surgical consideration. 1, 2
• Risser staging (0-5) indicates skeletal maturity and progression risk—stages 4-5 indicate near-complete maturity with lower progression risk. 1
• Sagittal balance assessment on lateral view to evaluate for hyperkyphosis or hypokyphosis. 3

Progression Risk Stratification

Skeletally immature patients with curves >20° have >70% likelihood of progression, while curves <20° have <30% progression risk. 1

Critical risk factors for progression include:

• Female sex (10:1 female-to-male ratio for curves >40°). 5
• Skeletal immaturity (Risser 0-3) with larger curve magnitude. 1
• Thoracic curves >50° may progress approximately 1° per year even after skeletal maturity. 1, 6, 5

Treatment Algorithm Based on Curve Magnitude

For curves <20° at Risser 4-5 (likely scenario at age 17):

• Observation with radiographic follow-up every 18 months is sufficient. 1
• No activity restrictions needed for tennis participation. 4

For curves 20-45° with remaining growth:

• Bracing may be considered if significant growth potential remains, though at age 17 this is less likely to be beneficial. 1, 2

For curves >45-50°:

• Surgical intervention with posterior spinal fusion and instrumentation is indicated due to continued progression risk even after skeletal maturity. 1, 6, 5

MRI Indications—Critical to Avoid Missing Neural Abnormalities

Obtain MRI of the complete spine without IV contrast if ANY of these atypical features are present: 1

• Left thoracic curve pattern (typical AIS is right thoracic). 1
• Short segment curve. 1
• Rapid progression. 3
• Back pain or neurological symptoms. 2, 3
• Age <10 years at presentation (early-onset). 1

Up to 2-4% of AIS patients have neural axis abnormalities (syrinx, Chiari malformation, tethered cord) that must be identified before any surgical intervention. 1

Asthma Medication Considerations

Low-to-medium dose inhaled corticosteroids (budesonide) have minimal effects on bone mineral density in adolescents and should not influence scoliosis management. 4

• Monitor growth velocity as inhaled corticosteroids may cause small, nonprogressive decreases in growth rate. 4
• The benefits of asthma control far outweigh theoretical concerns about bone effects at this age. 4
• No evidence suggests inhaled corticosteroids cause or worsen scoliosis. 4

Common Pitfalls to Avoid

Do not assume absence of symptoms means no progression—curves can progress silently, particularly in skeletally immature patients. 1

• Do not delay radiographic assessment—"mild" clinical appearance can underestimate actual curve magnitude. 2, 3
• Do not attribute spinal curvature to sports activity or asthma medications—AIS is idiopathic and requires proper evaluation. 2, 3
• Do not overlook atypical features that warrant MRI—missing neural axis abnormalities can lead to surgical complications. 1

Referral Criteria

Refer to orthopedic spine specialist if: 2

• Curve >20° in patient ≥10 years old. 2
• Any atypical features (left thoracic curve, pain, neurological findings). 2, 3
• Documented progression on serial radiographs. 1