The Journal of Bone and Joint Surgery, Vol 61, Issue 7 1052-1059, Copyright © 1979 by Journal of Bone and Joint Surgery, Inc
Cortical circulation of long bones
A Trias and A Fery
Intravascular injections of India ink in the femora of adult dogs revealed
the existence of two distinct vascular systems in the cortex. One courses
through the entire thickness of the cortex and is a regular, longitudinal
network of uniform capillaries which is in continuity with the periosteal
and endosteal networks. Once the haversian systems form a second network
appears, radiating from the bone marrow. That system, primarily transverse,
anastomoses in the haversian canals with the capillaries of the first
system. Therefore, the merging of the two networks occurs primarily in the
middle layer of the cortex. The direction of the arterial blood flow in the
mature animal is predominantly centrifugal, while the venous drainage is
centripetal. In the immature animal, the contribution of the periosteal
network is much greater. Because the two cortical systems are profusely
anastomosed with each other and with the periosteal and endosteal
circulatory networks, the blood can flow in either direction, depending on
physiological conditions.