Sacral spina bifida, also known as lamina bifida or arch bifida, is a posterior sacral defect caused by the failure to fuse the ossification centers on either side of the posterior arch of the spine due to impaired development during embryonic development. It can be divided into occult sacral spina bifida and dominant sacral spina bifida depending on whether or not the contents of the spinal canal protrude posteriorly. Occult sacral fissures usually have localized fissures with hairy or hyperpigmented skin, mostly without clinical symptoms, and a few with mild localized pain into adulthood. In contrast, overt sacral spina fissures have more protruding contents, resulting in localized rupture, cerebrospinal fluid leakage, neurological compression, and patients may have foot drop, clubfoot, etc., which may even affect urination and defecation.