Tubular hand bone growth during the latter half of the prenatal period: An allometric analysis

Abstract

The growth of the 19 tubular hand bones from fetal months 5 to 9 was studied by the allometric method. The hand bones were carefully dissected under a low power stereoscopic microscope. The length and breadth of all bones was found to be monophasic in relation to crown-rump length. In general, maximum bone and ossified shaft lengths in the same row group demonstrate similar allometric coefficients. The specific growth rate of ossified shaft length for all fetal hand bones is greater than the growth rate of maximum length. The highest allometric coefficients for both maximum length and ossified shaft length were obtained from the middle phalanges. The shape of the metacarpals and distal phalanges becomes thinner, while the other bones become thicker or maintain their length-breadth ratio. The relative growth pattern of the first proximal phalanx differed from the middle phalangeal group of the other digits. This suggests that current nomenclatures for the three bones of the pollex is appropriate.

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“…The results of the study demonstrate a minimal degree of allometry, while in men it is slightly higher than in women. This is consistent with the data that in the process of ontogenesis, despite the fact that the size of the hands varies by several orders of magnitude (from several tenths of a millimeter to several millimeters), their proportionality, including shape, does not change so much -the hands of human embryos are similar to the hands of an adult (Hattori, 1986). The general similarity of the proportions of the fetal and adult hands does not exclude minor changes in the shape and proportions of the hand during ontogenesis, as well as individual differences in these changes (Cihák, 1972).…”

Growth of the human metatarsal bones in the fetal period (13–24 weeks postconception): a quantitative study

“…The model is defined by the equation: Y= b.X k, were Y is the dependent variable (metatarsal length) X is the independent variable (crownrump length) and b and k the parameters to be estimated. These parameters can be interpreted as 'b' the Y value when X=I (ie, the value of metatarsal length when the fetus has 1 cm of crown-rump length) and 'k' the ratio of metatarsal growth to crown-rump variation (elasticity) [4][5][6][7][8][9][10][11][12][13][14][15][16][17]. To estimate the parameters b and k, the data (X and Y) were transformed into logarithms (log Y= log b + k. log X), enabling the use of the least square method.…”

“…The specimens were immersed in 10% formalin solution for 30 days at least [4]. The fixation was necessary because it facilitated the dissection of the bones, mainly on removing the periosteum.…”

“…Ultrasonography has long been used to monitor fetal growth, and recent technological advances in this field have made it possible to examine the fetal foot in the early stages of its development [2][3][4][5][6].…”

Ontogenetic allometry of the digital rays of the leopard gecko (Gekkota: Eublepharidae; Eublepharis macularius)

“…Differential growth of such bones is largely a postnatal/posthatching phenomenon (Farnum, 2007). Scaling patterns of phalanges and metapodials determine both their sizes and shapes in mammals (Hattori, 1986;Inouye, 1992;Elzanowski, 2001;Le Minor & Rozak, 2005;Weisbecker and Warton 2006), which together influence the sizes and shapes of the digits of the manus and pes.…”