Lumbosacral transitional vertebra associated with sacral spina bifida occulta: a case report.

Congenital malformations such as lumbosacral transitional vertebrae and spina bifida occulta constitute unrare anomalies and could affect the symptomatology of low back pain. A transitional vertebra is characterized by elongation of one or both transverse processes, leading to the appearance ofa sacralized fifth lumbar vertebra or a lumbarized first sacral vertebra. Furthermore, sacral spina bifida occulta is a developmental anomaly that corresponds to the incomplete closure of the vertebral column. In the present case report, we describe a case of a dried sacrum presenting a partially sacralized fifth lumbar vertebra and total spina bifida, extended from first to fifth sacral vertebra. A pseudoarthrosis is formed on the left side and the specimen could be incorporated in Castellvi's type IIa. Moreover, the incidence, morphology, clinical and surgical significance of these spinal malformations are discussed.