RESUMEN
The arterial supply of the human sacrum and coccyx was studied in 68 fresh cadavers of different ages by dissection, clearing, casting and radiography.The nutrient arteries of the sacral vertebrae penetrate the body from the dorsal, ventral and lateral surfaces of the body. The central branches are the main nutrient arteries of the body. Their numbers are constant and do not increase with the advancement of age. The peripheral branches are variable and supply only the outer collar of the body. According to the distribution of nutrient artery within the body of the sacrum, they can be classified into three types 1. predominant ventral nutrient artery pattern, 2. predominant dorsal nutrient artery pattern and 3. balanced nutrient artery pattern. It is found that in S_4 and S_5, type 1 occurs more frequently while type 2 occurs usually in S_1 to S_3. Type 1 is relatively common in adults but type 2 is prevailing in fetuses. There is few balanced pattern in different age groups. Both ventral and dorsal nutrient arteries are distributed in the central zone of the body and the lateral nutrient arteries supply that portion near the intervertebral foramen in the adults. The nutrient arteries within body anastomose with each other to form a dense arterial network.The nutrient arteries of the lateral part of the sacrum enter the bone through its ventral, dorsal and medial aspects. Among the dorsal nutrient arteries, there is a main artery that supplies the lateral mass.The arterial supply to the coccyx is scarce. It enters the coccyx mainly through the ventral surface.
RESUMEN
The arterial supply of the human sacrum and coccyx was studied on 56 fresh. cadavers of different ages by dissection, clearing, casting and radiography.All sacrums receive their blood supply from the lateral sacral arteries, the median sacral artery, the iliolumbar arteries and the fifth lumbar arteries. The median sacral artery, the lateral sacral arteries and their branches anastomose with each other and form the lattice anastomosis on the ventral surface of the sacrum.The anterior spinal canal branch bifurcates into an ascending and a descending branches. The former passes upwards to join the descending branch from the anterior spinal canal branch above it, they also anastomose with their contralateral counterparts, thus forming a rhombic system notable for its regularity.The posterior spinal canal branch also divides into an ascending and a descending branches and they join each other to dispose in a ladder anastomosis on the ventral surface of the laminae.The dorsal branch gives off three main sets of branches: the lateral, the medial and the muscular. The medial and the lateral branches both subdivide into an ascending and a descending branches and they anastomose with each other on the dorsal aspect of the sacrum.On the ventral surface, the coccyx obtains arterial supply from the median sacral artery and the lateral sacral arteries, while its dorsal surface mainly receives blood supply of the lateral sacral artery. Anastomosis has been found scarce on the ventral and dorsal surfaces of the coccyx.