Cartilage canals in the fetal elbow joint in man

The development of cartilage canals in the human elbow joint during fetal life was studied. Plastinated 600-1,000-microns-thick sections through the right and left arms of 12 fetuses with a crown-rump length of 90-360 mm and of a newborn infant were investigated. At a crown-rump length of 90 mm, cartilage canals have started to develop well within the distal and inferior aspect of the capitulum of the humerus, and are about to enter the dorsal side of the olecranon process. The radial head shows that vascularization does not begin before the 160-mm stage. The channels reveal a centripetal orientation and do not form any anastomoses. Branching occurs mainly in a dichotomous manner. The channels never originate from those areas of the perichondrium which reveal regular and parallel or very dense but irregular anchorage of collagenous fibres into the adjacent cartilaginous tissue.