Transitional vertebra

Transitional Vertebra

A transitional vertebra is a spinal anomaly characterized by features that are intermediate between two different vertebral types, most commonly observed at the junction between two spinal regions. This condition can occur at any of the major spinal transitions: cervicothoracic, thoracolumbar, or lumbosacral. Transitional vertebrae can lead to confusion in vertebral numbering, which may impact surgical planning and the assessment of spinal pathology.

Classification

Transitional vertebrae are classified based on their location and the characteristics they share with adjacent vertebral regions. The most common types include:

• Lumbosacral Transitional Vertebra (LSTV): This type occurs at the junction between the lumbar spine and the sacrum. It is the most frequently encountered form of transitional vertebra. An LSTV may have characteristics of both lumbar and sacral vertebrae, such as partial sacralization of the lowest lumbar vertebra or lumbarization of the first sacral segment.
• Cervicothoracic Transitional Vertebra: This variant is found at the junction between the cervical and thoracic spine. It may exhibit mixed features of both cervical and thoracic vertebrae, such as the presence of a rib or rib-like structure on a cervical vertebra.
• Thoracolumbar Transitional Vertebra: Occurring at the thoracolumbar junction, this type may display characteristics of both thoracic and lumbar vertebrae, including the presence of a rib or rib-like structure on what is typically considered a lumbar vertebra.

Clinical Significance

Transitional vertebrae are often asymptomatic and discovered incidentally during imaging studies for unrelated reasons. However, in some individuals, they can be associated with back pain and other neurological symptoms due to altered biomechanics or nerve compression. The presence of a transitional vertebra can complicate the identification of vertebral levels during surgical planning or when performing procedures such as lumbar punctures.

Diagnosis

Diagnosis of a transitional vertebra typically involves imaging studies, including X-rays, magnetic resonance imaging (MRI), or computed tomography (CT) scans. These imaging modalities can help delineate the anatomy of the transitional vertebra and identify any associated complications, such as disc degeneration or nerve compression.

Management

Management of symptoms associated with a transitional vertebra may include conservative measures such as physical therapy, pain management, and activity modification. In cases where conservative treatment is ineffective, and there is a clear pathological process related to the transitional vertebra, surgical intervention may be considered.

Epidemiology

The prevalence of transitional vertebrae varies in the population, with lumbosacral transitional vertebrae being the most common. The exact prevalence is difficult to determine due to the often asymptomatic nature of the condition.