Use of the Ultrasound Bone Maturity Indexes to Assess Whether Children Have Reached Their Final Height.

Objective: Ultrasound bone maturity indexes were used to assess whether children had reached their final height.

Methods: The follow-up study was performed between January 2022 and August 2024. Ultrasound bone maturity indexes, including the ossification ratio of the radius, ulna, and femur, and skeletal maturity score (SMS, the sum of the ossification ratio of the above three bones multiplied by 100), were collected from medical records, along with the children's age and height. The children were followed up to ascertain the annual increase in height during the 2 years before and after the ultrasound bone age assessment. Children were grouped according to whether they had reached their final height. The diagnostic performance (area under the curve, AUC) of ultrasound bone maturity indexes in assessing whether the children had reached their final height was confirmed.

Results: A total of 120 children (60 boys) with a mean age of 15.0 ± 1.7 years for boys and 14.1 ± 2.0 years for girls were included. At the attainment of final height, the mean values of radial, ulnar, and femoral ossification ratios, as well as the SMS, were 90%, 84%, 98%, and 271 in boys and 86%, 83%, 98%, and 267 in girls, respectively. Ultrasound bone maturity indexes were able to assess whether children had reached their final height, with the highest AUC for SMS of 0.99 (95% CI: 0.97, 1.01, cutoff value, 256) in boys and 0.95 (95% CI: 0.90, 1.00, cutoff value, 260) in girls.

Conclusion: A child's height stops increasing before the ossification ratios of the bones reach 100%. Ultrasound bone maturity indexes, especially SMS, demonstrate high diagnostic performance in determining whether children have reached their final height.