What is a butterfly vertebra?
A butterfly vertebra or sagittal cleft vertebra is a congenital anomaly characterized by a sagittal defect in the vertebral body caused by incomplete fusion of the two lateral halves of the vertebral body during embryogenesis and the persistence of remnants of the notochord between them. The butterfly vertebra is usually deficient anteriorly, causing a wedge shape and focal kyphosis. The two halves can be asymmetric, with intact pedicles and a posterior arch. Occasionally the two haves may be connected by an isthmus of bone.
When does the defect of a butterfly vertebra occur?
This anomaly occurs between the third and sixth weeks of gestation.
Where does this anomaly is located more frequently?
The butterfly vertebra may be single or multiple, and it occurs most frequently at the thoracolumbar spine. Cervical butterfly vertebrae are rare.
What are the clinical manifestations of a butterfly vertebra?
As patients are usually asymptomatic, the butterfly vertebra is usually detected incidentally. But this condition may alter the biomechanics of the spine, causing back pain, which is the most common presenting complaint. Occasionally disk herniation may occur. The presence of multiple butterfly vertebrae in the same patient should raise suspicion for other associated conditions and syndromes.
Which are the conditions associated with a butterfly vertebra?
This malformation can occur in isolation or associated with many conditions and syndromes, including Alargille syndrome, Crouzon syndrome, Pfeiffer syndrome, Kallmann syndrome, Jarcho-Levin syndrome, kyphoscoliosis, anterior spina bifida with or without anterior meningocele, spondylocostal dysostosis, VACTERL, and Mullerian hypo/aplasia.
How is made the diagnostic of a butterfly vertebra?
The diagnosis of a butterfly vertebra can be by X-ray, computed tomography (CT), or magnetic resonance imaging (MRI). Fetal ultrasonography may also demonstrate butterfly vertebra. The appearance of imaging studies of the two hemivertebrae separated by the central cleft is similar to butterfly wings. CT and MRI may contribute to demonstrating other congenital anomalies such as vertebra bars, supernumerary lumbar vertebrae, spina bifida, kyphoscoliosis, or diastematomyelia.
What is the treatment of butterfly vertebra?
The treatment is generally conservative for back pain. Occasionally, butterfly vertebra may be associated with disk herniation, which sometimes requires decompression.
What is the differential diagnosis of a butterfly vertebra?
The differential diagnosis of a butterfly vertebra includes vertebral collapse, wedge compression vertebral fractures, and metastatic disease.
CT scan of the abdomen reveals an incidental finding at the lumbar spine characterized by a cleft in the center of vertebral body L1, which originated the presence of two hemivertebrae, with the typical appearance of a butterfly vertebra, associated with left convex thoracolumbar transition scoliosis. Conclusion: L1 butterfly vertebra.