Certain diseases accompanied by spinal deformity

As mentioned earlier, spinal deformity is often one of the symptoms of diseases of other organs and systems. We considered it necessary to describe some of these diseases in this section, focusing not so much on the features of vertebral syndrome as on insufficiently known facts concerning the nosological forms themselves.

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Hereditary systemic skeletal diseases

One of the most extensive groups of diseases in which spinal damage is observed with high frequency are hereditary systemic skeletal diseases (HSSD). The classification of HSSD is based on the identification of three types of bone formation disorders:

• dysplasia - an endogenous disorder of bone formation,
• dystrophy - a disorder of bone metabolism,
• dysplasia-dysostosis is a mixed form of systemic disease associated with a formation disorder that develops secondary to a primary developmental defect in mesenchymal and ectodermal tissues.

Dysplasia. The localization of the zone of impaired bone formation in dysplasia is determined by the X-ray anatomical scheme of Ph. Rubin (1964), which distinguishes the following sections of the tubular bone: epiphysis, physis or the growth zone itself, metaphysis and diaphysis. According to these zones, M.V. Volkov identified epiphyseal, physeal, metaphyseal, diaphyseal and mixed lesions. In addition, taking into account the systemic nature of the pathology, dysplasias are distinguished that occur with the obligatory presence of vertebral syndrome (systemic spondylodysplasia) and dysplasias in which spinal damage is possible, but not obligatory.

Dystrophies. Hereditary dystrophies that involve bone tissue damage, including the spine, include Paget's osteopathy, marble bone disease, hereditary osteopenia, etc. Changes in the spine correspond to general bone changes characteristic of the above-mentioned diseases. Mycopolysaccharidoses, disorders of glycosaminoglycan metabolism, also belong to this group. The diagnosis of mucopolysaccharidosis is confirmed by medical and genetic testing and determination of the level of different types of glycosaminoglycans. The following occur with damage to the spine:

• mycopolysaccharidoses types I-II - Pfeundler-Hurler syndrome and //type - Hunter syndrome. Clinically, they are characterized by kyphotic deformation of the thoracolumbar region ("cat" back), radiologically - wedge-tongue-shaped form of the T12-L2 vertebrae (usually one or two in this zone);
• Mucopolysaccharidosis type IV - Morquio syndrome. The clinical and radiographic picture is the same as in Morquio-Brailsford spondyloepiphyseal dysplasia.
• mucopolysaccharidosis type VI - Maroteaux-Lamy syndrome. The back in this disease is straight, sometimes kyphosis. Radiographically - biconvex vertebrae, gradually acquiring a cuboid shape, but having a characteristic depression of the posterior endplate of the lumbar vertebrae. In the thoracolumbar region, posterior wedge-shaped vertebrae are detected. Hypoplasia of the C2 odontoid os is possible.

Mixed forms of systemic skeletal diseases (dysplasia-dysostosis)

The names of the diseases related to this group (cranio-clavicular, trichorinopharyngeal and chondroectodermal dysplasia, maxillofacial and spondylocostal dysostosis) have developed historically and rather reflect the localization of the affected organs, rather than the essence of the pathological processes. Spondylocostal dysostosis occurs with damage to the spine, which is characterized by short stature, shortening of the neck and trunk, the presence of scoliosis, and deformation of the chest. X-ray examination reveals multiple malformations of the vertebrae (usually mixed variants) and ribs (usually blocking of the posterior sections).

Arnold-Chiari malformation

Chiari malformation (the term "Arnold-Chiari malformation" is accepted in Russian literature) is a developmental defect characterized by the displacement of elements of the brain into the cranial part of the cervical spinal canal. WJ Oakes (1985) identifies several types of the anomaly.

Types of Arnold-Chiari malformation

Type of anomaly	Characteristic
Type1	Caudal displacement of the cerebellar tonsils below the level of the foramen magnum
Type 2	Caudal displacement of the cerebellar cochlea, 4th ventricle and brainstem below the line of the foramen magnum, usually associated with myelodysplasia
Type 3	Caudal displacement of the cerebellum and brainstem into the superior cervical spinal hernia
Type 4	Cerebellar hypoplasia

The development of Arnold-Chiari malformation can be caused by both craniovertebral malformations and any variants of spinal cord fixation. Violation of cerebrospinal fluid dynamics in the craniovertebral zone in Arnold-Chiari malformation leads to disruption of cerebrospinal fluid resorption and formation of cysts (see syringomyelia) inside the spinal cord. Vertebral syndrome is characterized by the presence of spinal deformities, often atypical.

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Syringomyelia

Until recently (and in Russian literature - still) syringomyelia (from the Greek syrinx - a pipe) was considered an independent chronic disease of the nervous system associated with the development of cysts (hydrosyringomyelia) in areas of pathological growth and subsequent disintegration of glial tissue. The introduction of magnetic resonance imaging into clinical practice and a more detailed study of this pathology now allows us to consider the development of cysts inside the spinal cord not as an independent disease, but as a symptom of various diseases.

Vertebral syndrome in syringomyelia is characterized by the presence of atypical (left-sided) scoliotic deformations of the thoracic region and early neurological symptoms, the first of which is usually asymmetry of abdominal reflexes. The genesis of vertebral syndrome in this case can be associated with both the primary disease that led to the development of syringomyelia and with a violation of the proper segmental innervation of the spine due to cystic damage to the spinal cord. In this section, we consider it necessary to provide an etiological classification, as well as tactical, diagnostic and therapeutic algorithms for syringomyelia developed by F. Denis (1998). According to the author, the primary treatment of syringomyelia should consist of treating the pathology that caused it. If it is successful, additional treatment is not required. If primary therapy is not effective, the main methods of secondary treatment are cyst drainage and syringo-subarachnoid shunting.

Neurofibromatosis

Neurofibromatosis (NF) is a disease of the peripheral nervous system characterized by the development of typical neurogenic tumors (neurofibromas) or atypical clusters of pigment cells (coffee-making spots, melanoma-like tumors), embryogenetically associated with paravertebral sympathetic ganglia. In the clinical classification of neurofibromatosis, two types of the disease are distinguished - peripheral and central. It should be remembered that in patients with neurofibromatosis, not only is malignancy of primary tumor nodes possible, but also a high risk of developing leukemia is genetically determined.

Vertebral syndrome in neurofibromatosis is characterized by the development of rapidly progressing, usually mobile kyphoscoliotic deformities. It should be remembered that the presence of pathological nodes inside the spinal canal often leads to neurological disorders both in the natural course of the deformity and in attempts at its conservative or surgical correction. The possibility of these complications must be taken into account by the doctor when drawing up a plan for examination and treatment of a patient with neurofibromatosis, and the patient and his parents must be informed about this.

Systemic hypermobility syndromes

Systemic hypermobility syndromes include a group of diseases that occur with insufficiency of the connective tissue fixing apparatus of the skeleton and internal organs (the so-called mesenchymal disorder syndromes) - Marfan, Ehlers-Danlos (Ehlers-Danlos) syndromes, etc. In this case, skeletal lesions are characterized by the development of severe but mobile scoliosis or kyphoscoliosis, asymmetrical deformations of the chest, joint deformations and arthropathies. F. Biro, H.L.Gewanter and J. Baum (1983) defined a pentad of signs of systemic hypermobility:

• when the thumb is abducted, the latter touches the forearm;
• the ability to passively extend the fingers of the hand to a position where the fingers are parallel to the forearm;
• hyperextension in the elbow joints more than 10°;
• hyperextension in the knee joints more than 10°;
• the ability to touch the floor with your palm while your knees are extended in a standing position.

To diagnose hypermobility syndrome, a combination of at least four of the five listed symptoms is required.

It should be remembered that in patients with systemic hypermobility syndromes, the period of transplant adaptation is sharply slowed down and the risk of their resorption is high in surgical treatment. For this reason, spinal and thoracic deformities recur in such patients after osteoplastic operations much more often than deformities not associated with systemic hypermobility.