Vascular pattern of the developing intertarsal joint in the domestic fowl

The origin and nature of vascular canals in the distal tibiotarsus and proximal tarsometatarsus of the fowl have been described. The vascular pattern was modified at different stages of growth and there were anastomoses between epiphyseal vascular canals in the proximal tarsometatarsus. Such anastomoses are not seen in other bone extremities of the fowl and their presence may be a consequence of the incorporation of tarsal elements in proximal tarsometatarsi. In all the distal tibiotarsi examined, a third epiphyseal ossification centre was present. The pattern of metaphyseal vessels in the distal tibiotarsus and proximal tarsometatarsus was altered in some young chicks. This finding may be the result of abnormal angulation of the intertarsal joint which would result in uneven joint loading.