Earlier appearance of Risser sign on ultrasound versus radiograph in adolescent idiopathic scoliosis.

Risser sign evaluation by ultrasound demonstrated a higher agreement rate in grades 3 and 4, whereas less agreement was found in grades 0-2. In the majority of cases with disagreement, ultrasound showed a higher grade than radiography, suggesting that ossification can be detected earlier with ultrasound than with radiography.