What is a butterfly vertebra? Bobyr Clinic

What is a butterfly vertebra

The disease is a non-fusion of the vertebral body, which can be partial or complete. The occurrence of pathology is associated with gene mutation and intrauterine growth retardation.

Causes

Disturbances in the formation and development of the fetus are provoked by the following factors:

Diseases of the endocrine system.
Infectious diseases.
Arterial hypertension.
Vitamin deficiency and mineral deficiency.
Exposure to radiation, chemical agents, etc.

Congenital anomalies of the spinal column include:

Short neck syndrome is a fusion of the cervical vertebrae.
Kimmerly's anomaly is a disorder of the formation of the first cervical vertebra.
Wedge-shaped vertebrae are vertebrae that include the hemibody, hemiarch and spinous process.
Spina bifida – butterfly spine.
Presence of additional cervical ribs.
Curvature in the lumbosacral region as an outcome of the process of sacralization and lumbarization.

Most often, splitting of the arches of the first sacral and fifth lumbar vertebrae occurs. With this pathology, the main substance of the spinal cord and its membranes protrude through the nonfusion.

If these nonunions are left untreated, children may develop progressive scoliosis. When “rachischisis” occurs. the vertebral body and arches remain unfused.

Symptoms

In most cases of pathology detection, closed clefting is diagnosed. With this type, the prognosis is more favorable.

In the case of open clefting, a hernial protrusion occurs, which is not covered by anything. If only the meninges enter the hernial sac, this is a meningocele. If it also includes the substance of the spinal cord, it is a meningomyelocele.

The disease is diagnosed immediately after the birth of a child, or in the first year of life. Manifested by the following violations:

Pain syndrome.
Impaired sensitivity.
Spinal column deformities.
Movement disorders.
Disturbances in the normal functioning of internal organs and the spinal cord itself.

Pain sensations are localized in the area where the disorder is located. The pain intensifies with movement. When the disorder is localized in the cervical region, headaches and neck deformities are characteristic.

If the disorder is localized in the thoracic region, improper formation of the chest, compression of the lungs, disruption of the heart, etc. occur.

When localized in the lumbar region - disruption of the intestines, decreased kidney function and disruption of their excretory function.

Diagnostics

An orthopedic doctor or surgeon can diagnose developmental disorders of the spinal column. When examined by a doctor, the following is revealed:

poor posture, possible formation of a hump.
Narrowing of the vertebra on the radiograph, the shape of butterfly wings is observed.

With a CT or MRI examination, it is possible to assess the condition of the intervertebral discs and spinal cord. They are used to confirm the diagnosis after examination by a specialist doctor.

Treatment

Treatment is prescribed after confirmation of the diagnosis. It can be either surgical or conservative.

The type of treatment depends on the severity of the anomaly.

As a rule, they prescribe:

Manual therapy.
Massotherapy.
Therapeutic gymnastics.
Wearing special corsets.
Physiotherapeutic treatment.
Water aerobics.

Physiotherapy

Exercise therapy helps strengthen the muscles of the back, helps reduce the degree of deformation, improve and stabilize the functioning of impaired organs.

Exercises are selected individually for each patient, it all depends on the degree of impairment.

Classic exercises include:

Walking on all fours - the recommended duration is approximately 2-3 minutes.
spinal traction
- the exercise is performed in a supine position, the patient stretches his heels down and the top of his head up. Execution time – 10-15 seconds.
Exercise “Bicycle” - the patient takes a supine position and makes movements with his legs that imitate riding a bicycle.
Scissors – lie on your back, put your hands behind your head, and perform cross leg swings with your legs.

Surgery

This treatment is recommended for severe forms of the anomaly.

The main purpose of the operation is to correct the deformity of the spinal column and stabilize it with special endocorrectors. Thanks to the operation, pain and disorders of organs and systems, as well as further progression of the pathology, are eliminated.

Types of operations for butterfly spine:

Spondylodesis – the essence is to fix adjacent vertebrae.
Spinal fusion with metal implants.
Removal of the modified vertebra.

Prevention

The risk of developing such a pathology can be reduced if the expectant mother follows a number of rules:

Quitting bad habits (if any)
Proper and rational nutrition. It should include the required amount of vitamins and microelements.
Regular rest.
Maintain moderate activity and regularly walk in the fresh air.
Take folic acid.

Conclusion

The correct formation of the spine begins even before birth. The child's parents play a significant role in this.

An anomaly of the butterfly vertebra is detected at an early age. The severity depends on the location and complexity of the pathology. But the presence of any anomaly requires timely treatment, which can be either surgical or conservative.

The risk of developing such a pathology increases with a family history.
It should be actively explored when making a diagnosis. Author: K.M.N., Academician of the Russian Academy of Medical Sciences M.A. Bobyr

Variants of spinal column anatomy

Spinal imaging is the most frequently performed examination in the radiology physician's practice. Whether you are a “classical” radiologist, a CT or MRI specialist, you will describe the spine every day. However, before studying the pathology of the spinal column, it is useful to pay attention to variants of normal anatomy and congenital anomalies that do not require intervention (leave-me-alone-lesions).

In the Russian-language literature, the term “pseudolisthesis” is rarely found, and in radiological reports such a condition is described as “displacement of the vertebrae within the framework of age-related physiological mobility.” This is a slight anterior displacement of the cervical vertebrae, caused by the elasticity of the ligamentous apparatus of the spinal column. Usually the C2 vertebra is displaced in relation to C3, less often - C3 to C4.

Pseudolisthesis of C2 in relation to C3 in a 7-year-old patient. No soft tissue swelling or other signs of traumatic injury

Differential diagnosis with traumatic or degenerative spondylolisthesis:

patient age under 8 years;
no signs of swelling of the surrounding soft tissues;
absence of other traumatic/other degenerative changes;
deviation from the posterior cervical line is no more than 2 mm.

Posterior cervical line (Svischuk line) is a line drawn between the anterior edges of the posterior arches of the C1 and C3 vertebrae.

Pseudolisthesis of C2 in relation to the C3 vertebra (white arrow). Note the normal position of C2 relative to the posterior cervical line (yellow) and the absence of soft tissue swelling. In the extension position, listhesis is not detected

Additional cervical ribs:

occur in approximately 1% of the population;
in about 80% of cases - bilateral;
more often observed in women;
usually (in the case of a small false rib) do not manifest themselves clinically;
originate from the C7 vertebra, much less often - from C6

Bilateral accessory cervical ribs originating from the C7 vertebra

There are true and false cervical ribs. The true cervical rib is connected to the transverse process by the costovertebral joint. With false cervical ribs, the articulation of the rib body with the transverse process occurs in the form of syndesmosis or synostosis.

There are also complete and incomplete cervical ribs. Complete cervical ribs externally resemble a real rib and, when localized at C7, are connected to the 1st thoracic rib through a cord, syndesmosis or synostosis. An incomplete cervical rib ends freely in the soft tissues. Small cervical ribs can be difficult to distinguish from hypertrophied transverse processes of the cervical vertebrae.

Three-dimensional reconstruction of CT examination of the chest organs. Replacement of additional cervical ribs on both sides, with the rib on the left appearing connected to the 1st thoracic rib

In those rare cases when a cervical rib provokes a clinical picture, it is manifested by symptoms of plexitis, namely:

aching pain in the area of the affected shoulder, which spreads to the entire limb; pain intensifies at night, with movements in the shoulder joint;
muscle weakness in the affected limb;
paresthesia;
decreased ulnar and carporadial reflexes;
trophic lesions (pasty and marbling of the upper limb, increased sweating or anhidrosis, excessive thinning and dryness of the skin, increased brittleness of the nails) are rare.

Fragment of an x-ray of a patient who went to the doctor with complaints of pain in the left shoulder. Left additional cervical rib

Differential diagnosis:

A fracture of the transverse process of a vertebra can sometimes mimic an additional cervical or hypoplastic thoracic rib. Its distinctive features:

zigzag, jagged fracture line, the edges are not sclerotic (in the case of a fresh fracture);
history of trauma;
soft tissue swelling, paraspinal hematoma may be observed.

Additional ribs are also found in the lumbar region, where they usually have no clinical significance.

The most common changes in the number of lumbar and sacral vertebrae. Sacralization of the fifth lumbar vertebra occurs when the transverse processes become large and form an anatomical connection with the sacrum and iliac bones of the pelvis, which can be bone, cartilaginous, or in the form of a joint; stationary or movable. In the latter case, it can cause pain. Functionally, only four vertebrae remain in the lumbar region. The frequency of occurrence of sacralization is about 8% of cases, more often it is one-sided.

Right-sided enlargement of the transverse process of the L5 vertebra (sacralization). There is no formation of a connection with the sacrum. Type I transitional lumbosacral vertebra.

The opposite picture is the lumbarization of the first sacral vertebra. It does not fuse with the sacrum, forming into a free vertebra. In this case, six vertebrae function in the lumbar region. The frequency of occurrence in the population is about 1%. The process can be one-sided, when one of the transverse processes grows larger than the other, which creates conditions for scoliotic deformity of the spine.

Lumbarization of the S1 vertebra. Six functional lumbar vertebrae are observed

Classification of transitional vertebrae according to Castellvi:

type I: enlarged or dysplastic transverse process (at least 19 mm): Ia: unilateral, Ib: bilateral changes;
type II: pseudoarticulation between the transverse process and the sacrum with incomplete lumbarization/sacralization; enlargement of the transverse process with pseudarthrosis: IIa: unilateral, IIb: bilateral;
type III: transverse process fuses with the sacrum to form complete lumbarization or sacralization, enlarged transverse process with complete fusion: IIIa: unilateral, IIIb: bilateral;
type IV: a combination of type IIa on one side and type III on the opposite side.

Correct diagnosis of the transitional vertebra is important for the correct correlation of symptoms with the level of the lesion, and in the case of planned surgical treatment of spinal pathologies in this area, it becomes necessary

The most accurate way to find out the exact number of vertebrae is to conduct an examination of the entire spinal column. However, in routine practice, the radiologist is still more often faced with examining only the lumbar vertebra.

In this case, the following guidelines are used:

Identify the last thoracic vertebra by the presence of ribs. The problem may be hypoplasia of the thoracic and additional lumbar ribs.
Some authors have proposed structures such as the origin of the right renal and superior mesenteric arteries and the bifurcation of the abdominal aorta as landmarks, but further studies have shown the inconsistent placement of these structures, which makes them unsuitable for landmarks.

The combination of anatomical variants can significantly complicate diagnosis: this patient has sacralization of the L5 vertebra and hypoplasia of the 12th pair of ribs. Due to the last anomaly, the radiographic picture could be perceived as normal, but the patient has 4 functional lumbar vertebrae

There is also a guideline by which it seems possible to determine the presence of lumbarization without counting the upper lumbar vertebrae. To do this, draw a straight line along the upper edge of the iliac bones. Normally, in an image taken with proper centralization, this pectineal line runs along the lower edge of the fourth or upper edge of the fifth lumbar vertebra. If you use this line, then normally there should be only one vertebra below the pectineal line, but with lumbarization two vertebrae are noted.

It is worth mentioning that developmental anomalies of the C1 arch are a heterogeneous group of congenital anomalies of varying degrees - from small defects of the arch to its complete absence. Radiologists usually use the morphological classification Currarino , which includes 5 types:

Type A: defect of the posterior part of the arch, two half-arches are present,
Type B: unilateral arc defect,
Type C: bilateral arch defect;
Type D: absence of the posterior arch with intact posterior tubercle,
Type E: the arch and tubercle are completely absent.

There is also a clinical classification that divides this anomaly into 5 subgroups depending on clinical manifestations:

accidental asymptomatic finding,
pain and stiffness in the head and neck area after injury,
chronic neck symptoms (pain, stiffness),
various neurological manifestations,
acute neurological symptoms after minor neck injury.

Type A and subgroup 1 are the most common (up to 80% of cases), and they can be classified as a variant of normal anatomy in the absence of signs of instability in this area. Incomplete fusion of the posterior part of the arch of the atlas is considered normal for children under 10 years of age.

To diagnose atlanto-occipital and atlanto-axial instability, the following measurements are taken:

Basion-dental distance (BDI - basion-dens interval) - a line drawn from the anterior edge of the foramen magnum to the apex of tooth C2; in adults does not exceed 12.5 mm on x-rays, 8 mm on CT scans

Basion-axial interval (BAI - basion-axial interval) is the distance from the anterior edge of the foramen magnum to a line drawn along the posterior surface of the C2 vertebral body. Used only for radiography, normally less than 12 mm

The atlas-tooth interval is the distance between the anterior surface of the C2 tooth and the posterior surface of the C1 cusp. Normally, it does not exceed 3 mm in an adult man, 2.5 mm in an adult woman and 5 mm in a child.

Most often occurs in the lumbar region. In cases where this is not accompanied by neurological deficits and abnormalities of the dural sac and spinal cord, this development option is not considered a pathology. This condition can be referred to as Spina bifida occulta, but recently the correctness of this term has been a controversial issue.

Incomplete fusion of the L5 vertebral arch

These include the butterfly-shaped vertebra, the posterior and lateral wedge-shaped vertebrae. These anomalies are associated with defects of embryonic development during the blastoma period. The butterfly-shaped vertebra consists of two triangular formations, with their apices facing each other. On a lateral x-ray, it appears as a wedge, slightly displaced posteriorly.

A butterfly-shaped vertebra is visualized in the thoracic region.

The lateral wedge-shaped vertebra, or hemivertebra, is the result of the development of only one half of the paired vertebral anlage. In some cases, hemivertebrae become fused with one of the adjacent normal vertebrae. In the thoracic region, the hemivertebra often has a one-sided rib.

Posterior wedge-shaped vertebrae are less common and their appearance is associated with vascular abnormalities.

Focal deposition of adipose tissue on T2, T1 and Fs sequences. The trabecular structure of bone tissue is depleted, but not changed. On fat-suppressed imaging, the affected area is homogeneously hypointense

Sometimes the replacement of bone marrow with adipose tissue during age-related changes does not occur diffusely, but in the form of “islands.” Such changes often mimic a vertebral hemangioma. On MR images, the fat island will show increased signal on T1 and T2 sequences with complete suppression of the signal on Fs sequences (Fs - fat saturation). Hemangiomas also appear hyperintense on T1 and may have both hyperintense and bone marrow isointense MR signal on T2WI sequences, but on fat-suppressed sequences in most cases will not appear as homogeneously hypointense as fat islands.

Hemangioma of the thoracic vertebra on T1Fs sequence. Its structure appears heterogeneous, with areas of increased and decreased signal

With CT studies, differential diagnosis is difficult - both the fatty “island” and the hemangioma look like areas of decreased density with a clear contour.

The most common anomaly is a conjoined nerve root - two nerves arise from adjacent segments together, covered by one "sleeve" of the dural sac, and subsequently split into two.

Options for the origin of nerve roots: Type 1—united nerve root; Type 2 - departure of two roots through one intervertebral foramen; Type 3 - anastomosis between nerve roots

The joint root itself does not cause any symptoms, but is often associated with vertebral anomalies such as spina bifida, spondylolisthesis.

Abnormal root origin can be visualized using MRI, MR tractography, X-ray and CT myelography (a study in which a radiopaque substance is injected into the subarachnoid space).

United nerve root on the right (arrow) on myelography of the lumbar spine

During an MRI examination, the combined nerve root will manifest itself:

asymmetry of the anterolateral corners of the dural sac (corner sign),
asymmetry of extradural fatty tissue (fat crescent sign)
sometimes it is possible to trace the parallel course of the affected root along its entire length, incl. at the level of the intervertebral disc (parallel sign).

On a series of axial MR tomograms, one can trace the anomalous joint origin of the lumbosacral nerve root on the right

If there is a suspicion of an abnormality in the origin of the nerve roots, the standard MRI examination of the spine should be supplemented with coronal sections.

Differential diagnosis should be carried out with a herniated disc, as well as with adhesive changes in the dural sac after arachnoiditis.

Sources:

Nardo L, Alizai H, Virayavanich W, Liu F, Hernandez A, Lynch JA, Nevitt MC, McCulloch CE, Lane NE, Link TM. Lumbosacral transitional vertebrae: association with low back pain. Radiology. 265(2):497-503. doi:10.1148/radiol.12112747
Konin GP, Walz DM. Lumbosacral transitional vertebrae: classification, imaging findings, and clinical relevance. A.J.N.R. American journal of neuroradiology. 31 (10): 1778-86. doi:10.3174/ajnr.A2036
Ghanem I, El Hage S, Rachkidi R et-al. Pediatric cervical spine instability. J Child Orthop. 2008;2(2):71-84. doi:10.1007/s11832-008-0092-2
Swischuk L.E. Anterior displacement of C2 in children: physiologic or pathologic. Radiology. 1977;122(3):759-63. doi:10.1148/122.3.759
Carrino JA, Campbell PD, Lin DC et al. Effect of Spinal Segment Variants on Numbering Vertebral Levels at Lumbar MR Imaging. Radiology. 2011;259(1):196-202. doi:10.1148/radiol.11081511
Ryan S, McNicholas M, Eustace S. Anatomy for Diagnostic Imaging 2e. Saunders Ltd. (2004) ISBN:0702026204.
Smoker WR. Craniovertebral junction: normal anatomy, craniometry, and congenital anomalies. Radiographics. 1994;14(2):255-77.
Weyreuther M, Heyde CE, Westphal M et-al. MRI Atlas: Orthopedics and Neurosurgery, The Spine. Springer. ISBN:3540335331.
Varghese B. et al. Cross-sectional study on incidental spinal findings in magnetic resonance imaging lumbar spine of patients with low back pain //West African Journal of Radiology. – 2021. – T. 24. – No. 1. – P. 38.
Böttcher J. et al. Conjoined lumbosacral nerve roots: current aspects of diagnosis //European Spine Journal. – 2004. – T. 13. – No. 2. – pp. 147-151.
Chiowchanwisawakit P. et al. Focal fat lesions at vertebral corners on magnetic resonance imaging predict the development of new syndesmophytes in ankylosing spondylitis //Arthritis & Rheumatology. – 2011. – T. 63. – No. 8. – pp. 2215-2225.
Blunk LB Lumbarization Accompanied by Spina Bifida Occulta in a Female Soccer Player // Journal of Athletic Training. – 2021. – T. 52. – No. 6. – P. S149.
Urrutia J., Cuellar J., Zamora T. Spondylolysis and spina bifida occulta in pediatric patients: prevalence study using computed tomography as a screening method //European Spine Journal. – 2021. – T. 25. – No. 2. – pp. 590-595.
McCormick CC. Developmental asymmetry of roots of the cauda equina at metrizamide myelography: report of seven cases with a review of the literature. Clin Radiol. 1982;33(4):427-34.
Song SJ, Lee JW, Choi JY et al. Imaging features suggestive of a conjoined nerve root on routine axial MRI. Skeletal Radiol. 2008;37(2):133-8.
Neidre A, Macnab I. Anomalies of the lumbosacral nerve roots. Review of 16 cases and classification. Spine. 1983;8(3):294-9.