Skeletal Age as a Determinant of Phalangeal Quantitative Ultrasound Measures of Bone Quality in Children and Adolescents

Abstract

Background: Quantitative ultrasonography of the proximal phalanges of the hand (QUS) has emerged as an attractive technical choice to assess bone quality features both in terms of bone mass and structure. Strong associations were found between QUS measures, chronological age and growth variables, such height, weight and pubertal stages. Aim: To evaluate the relationship between skeletal age and QUS variables and the influence of skeletal age on QUS variables after allowing for chronological age, height, weight and pubertal stage. Subjects and Methods: 235 healthy children and adolescents (85 boys and 150 girls) aged 3 - 18 years were examined. Height, weight, body mass index (BMI) were collected. Skeletal age was assessed by the third version of Tanner-Whitehouse method (TW3). QUS variables amplitude dependent speed of sound (AD-SoS, m/s) and bone transmission time (BTT, ∝sec) were measured by DBM Sonic BP IGEA sonograph. Results: Statistically significant positive correlations were found between AD-SoS and BTT and skeletal age (R2 = 0.76 in boys and 0.83 in girls for AD-SoS and 0.96 in boys and 0.93 in girls for BTT). A very close correlation was observed between skeletal age and BTT even after adjusting for chronological age, height, weight, and pubertal stage. In both sexes, chronological age, height and BTT resulted significant predictors of skeletal age. Conclusion: Skeletal age has emerged as an important determinant of phalangeal QUS measurements, mainly BTT. Skeletal maturity should be taken into account when QUS technology is used to evaluate bone mass and structure in children.