Cartilage canals in the tarsal navicular of the human foetus and infant.

We have analysed the development of the cartilage canals in the tarsal navicular in 26 human foetuses and infants, aged between 12 weeks after gestation and 10 months, using a technique of transparentation and serial histological sections of the bone. The formation of cartilage canals starts in the first 12 to 13 weeks of gestation and can be seen by transparentation at 17 weeks after gestation. They increase in number with the age of the foetus or infant and develop a branching pattern almost to the centre of the tarsal navicular. They begin and are more numerous on the dorsal surface of the cartilage structure.