Sesamoid Bones of the Hand: Relationships to Growth Skeletal and Sexual Development in Girls

Frequency and ages at appearance of the sesamoid hones of the hand was determined from 6-monthly longitudinal data in 83 girls. The relationship between the ages of appearance of the sesamoids to growth and skeletal and sexual development was studied. The ulnar sesamoid of the first metacarpophalangeal joint, encountered in every subject, was a better maturity indicator than the other sesamoids of the hand. The age, height, weight, percentage of adult height and skeletal age attained at appearance of the sesamoids showed the smallest variation with this sesamoid. Also it showed a very close relationship with the onset of secondary sex characters and with ages at initiation and peak of adolescent height velocity. Usually it became visible radiographically 0.5 years after the onset of pubic hair development, 0.75 years after the initiation of the height spurt and 0.7 years before peak height velocity. It indicates that puberty has already started and that height velocity is in the accelerating phase and that 88% of adult height is reached. The radial sesamoid of the first metacarpophalangeal joint, also encountered in every subject, was the best indicator of sexual maturity, but not as good an indicator of skeletal maturity. Usually it appears half a year after the ulnar sesamoid and half a year before the II and V metacarpophalangeal sesamoids, near peak height velocity and near the age of appearance of the axillary hair. Pubic hair and breast development is usually at stage 2 or 3 and the mean attained percentage of adult height is 90.5. The V metacarpophalangeal sesamoid, although showing significant relationships with the onset of secondary sex characters, growth velocity and skeletal development, is less important because it is not encountered in all subjects and it has lower correlation with ages of adolescent developmental events. The less frequent sesamoid bones of the hand, i.e., the II metacar­pophalangeal and the I interphalangeal sesamoids have no practical significance in relation to growth and development because they are absent in nearly half of the subjects