[Ultrasonography assessment of ossification foci of the wrist and pubertal growth spurt].

High-resolution ultrasound (US) of the hand and wrist was compared with radiography in 26 young patients (mean age: 11.4 years) to be submitted to orthodontic therapy. US scans were targeted on the ossification centers critical for the growth spurt, namely the pisiform and adductor sesamoid bones of the metacarpophalangeal joint of the thumb and the cartilage of the distal phalanx of the third finger. All images were retrospectively reviewed on a double-blind basis by two independent observers who gave a conspicuity score to each structure of interest. All the scores were submitted to statistical analysis with the Wilcoxon test. US images clearly demonstrated the initial appearance of the ossification centers of the pisiform and sesamoid bones. These structures appeared as hyperechoic spots causing marked acoustic shadowing. The persistence of the phalangeal cartilage was depicted as a thin rim interrupting the hyperechoic cortical profile of the bone. US results were statistically equivalent to radiographic findings in the pisiform [p (op1) = .3105; p (op2) = .8886] and sesamoid bones of the thumb [p (op1) = .1386; p (op2) = .354]. A statistically significant difference between the two techniques was found in the third finger cartilage (p (op1) = .0277; p (op2) = .0759) because its profile was poorly depicted on some US images. To conclude, wrist US is proposed as a simple and valuable radiation-free support examination for the follow-up of skeletal maturation in adolescents to be submitted to orthodontic therapy.