Rhachischisis posterior is a medical condition characterized by the incomplete closure of the posterior part of the spinal column during fetal development. This developmental anomaly results in an open defect in the back, leaving the spinal cord and meninges exposed. Though the term "rhachischisis posterior" is specific to this condition, there are a few synonymous phrases that can also be used to describe this condition. These include "posterior spinal column malformation" and "posterior spinal cord cleft". While these terms convey the same meaning, they are often used interchangeably to describe the same congenital disorder. Although rare, rhachischisis posterior requires prompt medical attention as it can lead to severe neurological complications.