THE VASCULAR PATTERN OF A GROWING AND FULLGROWN HUMAN EPIPHYSIS

Abstract

In an investigation of the nutrition of the unossified distal humeral chondroepiphysis and of the relation between the vessels and the endochondral ossification process, as well as of the vascular anatomy of the full-grown human epiphysis, radiopaque material was injected and angiograms, mostly stereoscopic, were taken. The material consisted of 31 human cadavers, aged 3 months to 80 years. All 10 year periods were represented. The distal end of the humerus was considered to lend itself better to the study of the vasculature in a growing epiphysis than the end of bones, often used for this purpose, where the endochondral ossification of the entire epiphysis occurs from a single ossific nucleus. The distal end of the humerus has 2 main ossific nuclei which appear in the temporary cartilage at very different ages. Vessel canals are demonstrable in the unossified temporary cartilage of the chondro-epiphysis, but never in that part forming the articular cartilage. Judging from the angiograms, the hyaline temporary cartilage in a growing epiphysis has its own vessels for nutrition of this large mass of cartilage. When the cartilaginous mass of the chondro -epiphysis has been reduced by growth of the ossific nucleus, the vessels of the cartilaginous tissue disappear and only the few vessels necessary for nutrition of the ossific nucleus persist. The primary function of the cartilage vessels is probably to nourish cartilages too large to be supplied by diffusion. Vessels do not grow into the cartilage in association with the beginning of ossification of the epiphysis. They are already present in the cartilage at the site where calcification and later ossification will occur. Endochondral ossification does not appear to be precipitated by lack of nutrition of the chondro-epiphysis. The only vascular supply of real significance to the ossific nucleus of the capitulum humeri consists of 1-2 vessels. These do not appear to be anatomical end vessels, but they may be regarded as functional end vessels during the period of growth. No signs of direct intraosseous intercommunication through the epiphysial plate between the epiphysis and the metaphysis are demonstrable in growing individuals. After bony union in the distal end of the humerus the epiphysial vessels are no longer isolated. The vascular topography of the vessels in the full-grown distal epiphysis of the humerus appears to be essentially the same as that in growing individuals.