Anatomic characterization of the radial and ulnar nutrient arteries in humans

The localization of nutrient foramens has been extensively studied in humans and other vertebrate animals. However, accurate information on the origin and extraosseous course of the nutrient arteries in some types of long tubular bones is lacking. Terminologia Anatomica, the international standard on human anatomic terminology, lists the radial nutrient artery (RNA) and the ulnar nutrient artery (UNA) as branches of the radial and ulnar arteries, respectively. Anatomy textbooks published in both German- and English-speaking countries regard both the RNA and UNA as branches of the anterior interosseous artery.

To clarify the anatomic characteristics of the RNA and UNA in humans, we reexamined the origin and course of these arteries by cadaveric dissection.

Almost all RNAs and UNAs branched from the ulnar artery or its tributaries. In typical cases, the RNA branched from the anterior interosseous artery and the UNA branched from the proximal part of the ulnar artery or the anterior interosseous artery. These findings are reasonable from the perspective of regional anatomy, since the ulnar artery passes more deeply than the radial artery in the proximal forearm and thus the proximal part of the ulnar artery and its major branches are situated more closely to the radial and ulnar nutrient foramens.

Based on our findings, it is necessary to correct the position of the RNA and UNA in the arterial hierarchy of T. Anatomica for accurate morphological description.