Scoliosis Cobb Angle Calculator

Bracing is most effective while significant growth remains, which this calculator models as a Risser sign of 2 or lower combined with a Cobb angle between 25 and 39 degrees (the SRS bracing range; curves at or above 40 degrees move to a surgical- consultation recommendation instead, even in a skeletally immature patient). Once the Risser sign reaches 3 or higher, the iliac apophysis has ossified enough that remaining growth -- and therefore the curve's ability to respond to bracing -- has substantially declined, so observation or surgical evaluation typically replaces a new bracing trial at that point.

Progression risk in this calculator is driven primarily by curve magnitude and Risser sign, and both typically differ sharply between those ages: a 12-year-old is more likely to have a low Risser sign (more remaining spinal growth) and to be within the peak pubertal growth-velocity window, both of which this calculator scores as higher-risk than the same curve measured in a skeletally more mature 16-year-old with a higher Risser sign.

No -- this calculator's severity band, progression-risk estimate, and treatment recommendation are all computed from Cobb angle, Risser sign, age, and sex. Curve location (thoracic, thoracolumbar, or lumbar) is captured for reference only in this simplified model, even though real-world curve management also considers how curve location affects trunk balance and cosmetic prominence.

It takes the progression rate measured between the prior and current Cobb angle (the change in degrees divided by the months between the two X-rays, annualized to degrees per year) and adds that rate to the current angle, assuming the same rate of change continues linearly for a further twelve months. It is a simple linear projection, not a clinical prediction -- actual curves can accelerate, plateau, or slow as skeletal maturity changes.