Region of the back including the LUMBAR VERTEBRAE, SACRUM, and nearby structures.

Five fused VERTEBRAE forming a triangle-shaped structure at the back of the PELVIS. It articulates superiorly with the LUMBAR VERTEBRAE, inferiorly with the COCCYX, and anteriorly with the ILIUM of the PELVIS. The sacrum strengthens and stabilizes the PELVIS.

The lumbar and sacral plexuses taken together. The fibers of the lumbosacral plexus originate in the lumbar and upper sacral spinal cord (L1 to S3) and innervate the lower extremities.

VERTEBRAE in the region of the lower BACK below the THORACIC VERTEBRAE and above the SACRAL VERTEBRAE.

Paired bundles of NERVE FIBERS entering and leaving the SPINAL CORD at each segment. The dorsal and ventral nerve roots join to form the mixed segmental spinal nerves. The dorsal roots are generally afferent, formed by the central projections of the spinal (dorsal root) ganglia sensory cells, and the ventral roots are efferent, comprising the axons of spinal motor and PREGANGLIONIC AUTONOMIC FIBERS.

A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.

Congenital defects of closure of one or more vertebral arches, which may be associated with malformations of the spinal cord, nerve roots, congenital fibrous bands, lipomas, and congenital cysts. These malformations range from mild (e.g., SPINA BIFIDA OCCULTA) to severe, including rachischisis where there is complete failure of neural tube and spinal cord fusion, resulting in exposure of the spinal cord at the surface. Spinal dysraphism includes all forms of spina bifida. The open form is called SPINA BIFIDA CYSTICA and the closed form is SPINA BIFIDA OCCULTA. (From Joynt, Clinical Neurology, 1992, Ch55, p34)

Congenital, or rarely acquired, herniation of meningeal and spinal cord tissue through a bony defect in the vertebral column. The majority of these defects occur in the lumbosacral region. Clinical features include PARAPLEGIA, loss of sensation in the lower body, and incontinence. This condition may be associated with the ARNOLD-CHIARI MALFORMATION and HYDROCEPHALUS. (From Joynt, Clinical Neurology, 1992, Ch55, pp35-6)

A common congenital midline defect of fusion of the vertebral arch without protrusion of the spinal cord or meninges. The lesion is also covered by skin. L5 and S1 are the most common vertebrae involved. The condition may be associated with an overlying area of hyperpigmented skin, a dermal sinus, or an abnormal patch of hair. The majority of individuals with this malformation are asymptomatic although there is an increased incidence of tethered cord syndrome and lumbar SPONDYLOSIS. (From Joynt, Clinical Neurology, 1992, Ch55, p34)

Rare congenital deformity syndrome characterized by a combination of five anomalies as a result of neural tube defect. The five anomalies are a midline supraumbilical abdominal wall defect (e.g., OMPHALOCELE), a lower STERNUM defect, a congenital intracardiac defect, an anterior DIAPHRAGM defect, and a diaphragmatic PERICARDIUM defect (e.g., PERICARDIAL EFFUSION). Variants with incomplete and variable combinations of the defects are known. ECTOPIA CORDIS; CLEFT LIP; and CLEFT PALATE are often associated with the syndrome.

A congenital or acquired protrusion of the meninges, unaccompanied by neural tissue, through a bony defect in the skull or vertebral column.

A condition with congenital and acquired forms causing recurrent ulcers in the fingers and toes. The congenital form exhibits autosomal dominant inheritance; the acquired form is found in workers who handle VINYL CHLORIDE. When acro-osteolysis is accompanied by generalized OSTEOPOROSIS and skull deformations, it is called HAJDU-CHENEY SYNDROME.

Congenital malformations of the central nervous system and adjacent structures related to defective neural tube closure during the first trimester of pregnancy generally occurring between days 18-29 of gestation. Ectodermal and mesodermal malformations (mainly involving the skull and vertebrae) may occur as a result of defects of neural tube closure. (From Joynt, Clinical Neurology, 1992, Ch55, pp31-41)