Other Congenital Vertebral Anomalies
The spine is made up of group of bones called vertebrae. Vertebral anomalies are defects or malformations of the spine that are present during birth. These defects are categorized into malformation, disruption, and deformation.
Malformation is the failure in the formation of the spine causing the vertebra to be absent completely or improperly formed (hemi or wedge vertebra). If two hemivertebra occur at the same level, it may lead to butterfly vertebra and if the vertebra fails to differentiate it may lead to block or fused vertebra. Disruption is the defect or damage of the spine that formed normally during the embryo development. Deformation is abnormal shape of a vertebra or the entire spine during the embryonic development.
There are various vertebral anomalies of which some of the commonly occurring anomalies include:
- Congenital scoliosis - It is the sideway curving of spine that occurs in children whose vertebrae are abnormally formed during their development in the womb. This abnormality develops in the fetus at 4 to 6 weeks of gestation. It may be present at birth or may be present along with kidney or bladder disease.
- Congenital kyphosis - It is a condition which occurs as a result of failure of segmentation or defect in the formation of the vertebrae. Defect of segmentation causes forward bending of the spine giving hunchback appearance. If this condition is left untreated, it leads to paraplegia, a condition where there is loss of movement and sensation in the lower part of the body including both legs.
- Congenital lordosis - This condition causes inward curving of the spine which makes the child difficult to sit, stand, or walk. If this condition occurs in the upper or (thoracic) region of spine, the distance between spine and the chest is reduced and your child may have respiratory problems. If lordosis occurs in the lower back region (lumbar), the spine may approach the abdominal wall.
- Sacral and Lumbosacral Agenesis - It is a rare congenital condition, occurs when there is failure of formation of sacrum (lower spine). Some of the risk factors such as maternal diabetes and deficiency of mother's diet can cause sacral agenesis. In severe cases, sacral agenesis leads to lumbosacral agenesis. Lumbosacral agenesis is characterized by partial or total absence of lumbar vertebrae and lower thoracic vertebrae.
- Basilar impression - It is a deformity of the bones at the base of the skull. It occurs when the floor of the skull is pressed by the upper portion of the cervical spine. This condition may cause neurologic damage from an injury and deterioration of cerebrospinal fluid flow. Basilar impression is further divided into primary and secondary. Primary basilar impression is associated with other vertebral defects such as Klippel-Feil syndrome, odontoid anomalies, and atlas hypoplasia. Secondary basilar impression occurs when the osseus structures present at the base of the skull becomes soft.
- Occipitocervical synostosis - It is a condition characterized by partial or complete union of the 1st cervical vertebra atlas and the base of the occiput of the skull. This process is known as occipitalization of the atlas. Children usually develop the symptoms after trauma or some of the children do not get any symptoms throughout their life. The common symptoms include weakness and lack of coordination in the lower limbs and sometimes in the upper limbs.