Overlapping Sanders scores challenge age-based AIS/JIS classifications.

Area of Science:

• Orthopedics
• Pediatric Spine Surgery
• Skeletal Maturity Assessment

Background:

• Idiopathic scoliosis classification traditionally uses age, differentiating juvenile (JIS) from adolescent (AIS).
• Age-based cutoffs may not accurately reflect physiological maturity, impacting curve progression prediction and treatment decisions.

Purpose of the Study:

• To investigate skeletal maturity differences around the JIS-AIS age threshold using the Sanders Maturity Scale (SMS).
• To evaluate if SMS provides a more accurate assessment of maturity than chronological age.

Main Methods:

• Retrospective review of a multicenter pediatric spine registry.
• Inclusion of 637 patients (7-13 years) with idiopathic scoliosis and documented SMS scores.
• Analysis of SMS distributions across age bands (9-10 vs. 10-11 years) and demographic factors.

Main Results:

• Significant overlap (50%) in SMS scores between 9-10 and 10-11-year-olds.
• Many AIS patients showed skeletal immaturity comparable to JIS patients.
• Factors like height, weight, BMI, sex, and ethnicity correlated with skeletal maturity variations.

Conclusions:

• Chronological age is an unreliable indicator of skeletal maturity and growth risk in idiopathic scoliosis.
• The Sanders Maturity Scale (SMS) provides a more precise, physiology-based classification.
• Adopting SMS-based classification can improve treatment individualization, clinical trial stratification, and patient outcomes.