Congenital anomalies of the lumbosacral spine

The aim of the study is to compare the structure of the lumbosacral transitional vertebra, which were detected by computed tomography (CT) and identified on dried human sacral, and to discuss possible pathogenetic mechanisms of this congenital malformation. The article presents 9 cases of lumbosacral transitional vertebra, including 6 cases of L5 sacralization and 3 cases of S1 lumbarization. The formation of the transitional lumbosacral vertebra is genetically determined. All types of such developmental anomaly can be detected only on CT. L5 sacralization repeats the process of fusion of the sacral vertebra into a single bone. A lack of the costotransverse bars of the first sacral vertebrae fusion results in the S1 lumbarization.