Congenital vertebral anomaly

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at August 27, 2016
StartDiseasesCongenital vertebral anomaly

The vertebrae are the individual bones that make up the spine, and if they are not correctly shaped, it may cause symptoms ranging from back pain to paralysis. During the process of fetal development, it is possible for the vertebrae to become malformed. A congenital vertebral anomaly is any type of malformed vertebrae condition that is present at birth.


Definition & Facts

It is quite common for vertebrae to be abnormally shaped, but typically these anomalies are very minor. Though not all congenital vertebral anomalies cause severe problems, about 15 percent of them result in problematic deformities.

There are five basic types of anomalies that occur among newborns. Hemivertebrae are vertebrae that are shaped like a wedge, causing scoliosis or lordosis, and block vertebrae are one or more vertebrae that are fused together. Other less common anomalies are spina bifida, transitional vertebrae, and butterfly vertebra

Symptoms & Complaints

The symptoms of congenital vertebral anomalies can vary quite a lot depending on what type of anomaly a patient has. Wedge-shaped vertebra cause the spine to turn at an angle, causing the spine to curve forwards, backwards, or sideways. This can cause pain due to pulled muscles or pinched nerves, possible paralysis in a limb, and improperly functioning organs due to lack of space.

Fused block vertebrae can cause neck pain or back pain, and mobility throughout the spinal column is limited. Spina bifida occurs when the vertebrae do not close entirely around the spinal cord, and this type of anomaly can cause leg paralysis, abnormal brain shapes that lead to learning disabilities, bladder problems, and kidney problems.

In very serious cases of spina bifida, a person may have a meningocele, which happens when the protruding membranes around the spinal cord form a bump on the patient's back. There typically aren't any noticeable symptoms for butterfly vertebrae, which just have a narrowed middle section.

Transitional vertebrae are vertebrae that may resemble a nearby vertebrae instead of being in their proper shape. Symptoms of transitional vertebrae include arthritis, spinal cord compression, and back pain.


All types of congenital vertebral anomalies are caused by a vertebrae that does not form properly during fetal development. This is most often due to a genetic mutation of some sort, which can be inherited or occur spontaneously. Congenital vertebral anomalies tend to occur alongside other genetic conditions such as Down syndrome and Kabuki syndrome.

In addition to genetic factors, there are certain other factors that can increase the chances of a fetus developing an anomaly. The wedge-shaped vertebrae associated with scoliosis can occur if the blood supply to the fetal vertebrae is inadequate. Spina bifida is often caused by folate deficiencies, but there are also some cases caused by alcohol consumption during pregnancy.

Block vertebrae, transitional vertebrae, and butterfly vertebrae do not seem to have any precise cause beyond basic genetics. Some researchers theorize that environmental factors may enhance a fetus' likelihood of getting a congenital vertebral anomaly if they already have a genetic susceptibility to the trait. 

Diagnosis & Tests

In very severe cases, congenital vertebral anomalies do not need many tests because there are immediate visual signs of an anomaly. This is typically the case of infants born with spina bifida, since they often have a large cyst-like sac on their spine. If a wedge shaped vertebra is very severe, the curved spine may also be immediately noticeable.

However, there are many cases where a congenital vertebral anomaly is not very visible at first. In these cases, children are only diagnosed after their parents take them to the doctor because their child is having difficulty learning to walk. Very mild cases of congenital vertebral anomalies may even go undiagnosed until adulthood, when a patient goes to the doctor because of persistent pain.

The most common test used to diagnose a congenital vertebral anomaly is a basic X-ray test. This will show the bones of the body, and most abnormally shaped vertebrae are evident. Magnetic resonance imaging (MRI) scans and computed tomography (CT) scans can also be used to get an even clearer image of the anomaly.

Treatment & Therapy

Treatment for congenital vertebral anomalies will depend on the level of severity and whether or not any symptoms are occurring. For example, butterfly vertebrae normally cause no symptoms, so doctors typically do not recommend any treatments. Instead, they just advise that patients avoid lifting heavy materials, since misshapen vertebrae increase risks of back injuries.

Block vertebrae cannot be fused through spinal fusion surgery, so most treatment will rely on medications to relieve pain and physical therapy to prevent any damage to muscles or nerves. If a patient has a very mildly misshapen wedge vertebra, no treatment beyond physical therapy may be done.

Wearing a back brace can sometimes prevent the curve from worsening. However, if the spinal curve is severe, surgery may be needed to straighten the spine. There are many different surgeries used to treat scoliosis, lordosis, and kyphosis. Sometimes the hemivertebra can be removed, or rods can be added to compensate for the abnormal shape of the vertebra.

In contrast, spina bifida treatments tend to be immediate and intensive because physicians need to put the spinal cord back into the spine, close the back and spine opening, and install shunts to drain excess cerebrospinal fluid. Children and adults with spina bifida will require extensive evaluations and therapy to avoid any further problems. 

Prevention & Prophylaxis

Since so many congenital vertebral anomalies are genetic, it can be difficult to prevent them. Patients with a congenital vertebral anomaly may benefit from genetic counseling so they can understand the risks of passing the vertebrae condition on to their offspring.

The chances of a fetus developing spina bifida can be significantly lowered as long as the mother gets enough folic acid during pregnancy. Leading a healthy lifestyle while pregnant might slightly lower risks of congenital vertebral anomalies, but there is no way to conclusively prevent most of them from happening.