Congenital kyphosis

Kyphosis - curvature of the spine in the sagittal plane with the formation of convexity facing posteriorly.

[1], [2], [3], [4], [5], [6]

What causes congenital kyphosis?

According to the classification of R. Winter et al. Congenital kyphosis is divided into three main groups:

• kyphosis on the soil of formation anomalies;
• kyphosis on the basis of segmentation anomalies;
• kyphosis on the basis of mixed anomalies.

McMaster et al. Introduced into it a group of unclassifiable deformations. Dubousset singled out in a separate group special kyphotic deformations, which he called a rotational dislocation of the spine.

Kyphosis based on vertebral anomalies is the most common type of congenital kyphosis, ranging from 61 to 76%. These deformations are based on the following types of anomalies; anterior and antero-lateral sphenoid vertebrae, posterior half-vertebrae, posterolateral quadrant of the vertebral body, a butterfly vertebra and agenesis of the vertebral body.

Kyphosis on the basis of segmentation anomalies. Anomalies of segmentation in frequency stand in second place after formation anomalies and amount to 11-21%. Patients with these deformities can be divided into two subgroups, depending on the symmetry of the lesion-anterior or anterolateral non-segmented block. The length of the block can vary from two to eight or nine vertebral bodies. It can be localized at any level, but more often in the thoracolumbar and lumbar spine.

If the segmentation defect is located in front, a "clean" kyphosis is formed, if asymmetrically - kyphoscoliosis. The progression of deformation is variable and depends on the symmetry of the block and the safety of the posterior sections.

Kyphosis on the basis of mixed anomalies is the result of the simultaneous existence of an unsegmented vertebral body with impaired formation at one or two adjacent levels, and usually located contralately. The frequency of such kyphosis varies from 12 to 15%.

Kyphosis on the basis of unclassifiable anomalies can be found in any part of the spine. The purity is 5-7%.

Rotational dislocation of the spine. Any anomaly can be the basis of deformation. The main feature - kyphosis is located between two congenital lordoskolioticheskimi multidirectional arcs. Meet at any level, but more often in the upper thoracic and thoracolumbar parts. The kyphosis is in the shape of an island, usually coarse, its development is accompanied by the collapse of the spinal column. The spinal cord is deformed according to the deformation of the vertebral canal, that is, it is twisted in a short length, and sharply.

Symptoms of kyphosis

Kifotic deformation (kyphosis) can have a vertex at almost any level, be flat or pointed, often (up to 70% of cases) has a scoliotic component. Congenital kyphosis is almost always rigid, and most cases are accompanied by neurologic symptoms of varying severity. Very often (up to 13% of cases) are combined with a variety of congenital anomalies outside the localized localization.

Clinical and X-ray classification of kyphosis

The classification is based on literature data.

The type of anomaly on the soil of which the deformation sported

• Posterior (posterolateral) tics (semi-vertebrae).
• The absence of the vertebral body is asoma.
• Microspondylia.
• Concentration of vertebral bodies is partial or complete.
• Multiple anomaly.
• Mixed anomalies.

Type of deformation.

• Kyphosis,
• Kifoscoliosis.

Localization of the deformation peak.

• Cheyno-thoracic.
• Upper thoracic.
• The Middle chest.
• Lower chest.
• The thoracolumbar lobe.
• Lumbar.

The magnitude of kyphotic deformation.

• Up to 20 ° - I degree.
• Up to 55 ° - II degree.
• Up to 90 ° - the third degree.
• Over 90 ° - IV degree.

Type progressing deformation.

• Slowly progressing (up to 7 ° and year).
• Rapidly progressive (more than 7 ° per year).

Age of primary detection of deformation.

• Infant kyphosis.
• Kyphosis of young children.
• Kyphosis of adolescents and young men.
• Kyphosis of adults.

The presence of the contents of the vertebral canal in the process.

• Kyphosis with neurological deficit.
• Kyphosis without neurological deficit.

Associated abnormalities of the spinal canal.

• Diastematomyelia.
• Diplomacy.
• Dermoid cysts.
• Neuro-en- terric cysts.
• Dermal sinuses.
• Fibrous constrictions.
• Abnormal spinal roots.

Concomitant anomalies of extrinsic localization.

• Anomalies of the cardiopulmonary system.
• Anomalies of the thoracic and abdominal wall.
• Anomalies of the urinary system.
• Anomalies of the extremities.

Secondary degenerative changes in the spine.

1. None.
2. Present in the form:
   • osteochondrosis;
   • spondylosis;
   • spondyloarthrosis.

[7], [8]

Diagnosis of kyphosis

Radiographic picture of congenital kyphosis is very characteristic and there are no special difficulties in diagnosis.

The profile of the spondylograms is determined using the Cobb method, the magnitude of the kyphotic deformation.

Diagnosis of kyphosis is not only in the conduct of the survey spondylography. MRI and CT can be useful here. To determine the functions of intervertebral disks in the parasagittal parts of the spine, functional spondylography is used - in the lateral projection, in the position of the maximum possible flexion and extensibility of the patient's spine. In all cases of congenital deformity of the spine, study of the contents of the spinal canal - contrast study, MPT, KT. Neurological examination is mandatory.

[9], [10], [11]

Treatment of kyphosis

Conservative treatment of kyphosis is unequivocally recognized as ineffective, as in the best case it can only slow the progression of the deformity somewhat.

Modern surgical treatment of congenital kyphosis is built on the collective experience of leading world clinics.

Congenital kyphosis type I (on the basis of formation anomalies)

[12],

Treatment of early deformities

Usually patients younger than 5 years with kyphosis less than 75 ° are effectively treated with only a posterior spinal fusion. The method is based on the principle of preserving the growth potential of vertebral bodies during the "arrest" of their dorsal parts. The zone of posterior spinal fusion should be larger than the anomalous zone by one normal segment cranially and caudally. This is necessary for the formation of lordosis above and below the kyphosis zone, compensating for any residual kyphosis.

If there is not kyphosis, but kyphoscoliosis, treatment is similar. However, even with a good posterior block, the growth of the apical vertebrae can continue laterally and horizontally. This is the phenomenon of the crankshaft, described by Dubousset. The development of this complication means progression of deformation. In this case, there are urgent indications for anteroposterior epiphysis on the convex side of the deformation.

Another issue is the age of the patient. Given the nature of congenital kyphosis, monitoring the patient in dynamics is meaningless. An early Gnostic bottom and a reliable posterior fusion are necessary before the development of coarse deformity. The earlier the patient is operated, the better. The earliest permissible age for surgical intervention is 6 months.

The principle of solving the problem, depending on the magnitude of deformation (according to Cobb) with respect to kyphoses is not reliable. The gently sloping kyphosis of 30 ° in the middle thoracic region is almost normal, the same kyphosis in the thoracolumbar region is already pathology, and the kyphosis of 10 ° in the lumbar region is a rough pathology. Ostrovershinny kyphosis 50 ° in the middle thoracic area - pathology, and gently sloping kyphosis of the same magnitude in this same section - only the upper limit of the norm. The results obtained indicate a high efficiency of the method. Not only there is no progression, but constantly reveal self-correction of deformation. However, even in children younger than 5 years, it is possible and very real development of a false joint block. Therefore, after 6 months in all cases, a repeat operation with revision of the zone of spondylodesis and the laying of additional bone-plastic material is shown. No cases of hypercorrection were noted, but if there is such, blocking of the anterior spine is indicated. Criticism of the method is based on the fact that early siondilodez causes some truncation of the trunk. However, a large loss of height of the trunk occurs during the growth of the deformed spine and is underlined by progressive kyphosis.

Treatment of late formed deformities

These cases seem much more complicated, as they require a two-stage treatment - ventral and dorsal spondylodesis. Accordingly, the risk of complications increases.

Preliminary traction performed to "soften" the deformation before anterior spondylodesis is meaningless. The ligamentous apparatus and the cartilaginous tissue in the region of the tip of the kyphosis are inelastic, therefore, beyond the correction that is determined on the functional spondylograms in the hyperextension state, nothing can be obtained. Tractions are shown only in a few patients, whose reduction in lung function is combined with sufficient mobility of the spine, which allows for some correction during the period of pulmonary rehabilitation. The best form is halo-pelvic traction, which allows the patient to move independently, which is very important in the sense of preventing thromboembolic complications and osteoporosis. Usually the duration of traction is no more than 2 weeks. Since with congenital kyphosis, the application of traction is dangerous because of the high risk of paraplegia due to the tension of the spinal cord, it should be used rarely and accompanied by neurologic control at least twice a day.

The type of ventral spinal fusion depends on the severity and extent of kyphosis. Relatively structurally unstable deformations, the minimal of those that are subject to ventral interference, can be effectively corrected by the operation of anterior spondylodease by the type of partial replacement of the vertebral body. It is extremely important to adequately expose the anterior sections with removal of the anterior longitudinal ligament, discs and cartilaginous tissue at the apex of deformation. Proximal and caudal from the kyphosis zone, one normal disc is removed. After that, the deformation becomes more mobile. In order to install a graft-spacer, you need a simultaneous pull for the patient's head and manual pressure on the top of the kyphosis from behind. Additionally, the spinal cord is laid in the intervertebral spaces. Rear spondylodesis is performed on the same day. For coarser kyphoses, the use of a spacer is necessary. The more pronounced kyphosis, the more bone-plastic material is used. For large deformations, a gross error will be the use of one transplant-spacer by composing an "empty" space between it and the vertex of kyphosis. It is necessary in such cases to use several rigid autografts from the crest of the tibia.

Dorsal intervention includes fixation of the spine with segmental instrumentation (CDI) and autonomic spondylodesis. The planning of the dorsal stage involves the identification of hook points.

Treatment of intermediate deformations

A patient with such a deformation presents a serious problem, since a posterior spondylodease is sufficient for early deformities, and for combined kyphosis, combined kyphosis treatment is necessary. If in doubt, it is better to perform a back spondylodease, and after 6 months to inspect the block and supplement with bone-plastic material, regardless of how strong it is to the surgeon Immobilization with the corset is performed for a period of 1 year. If the false joint of the block then develops, anterior spondylodesis is indicated.

The selection of the ventral and dorsal spondylodesis zone is basically a biomechanical problem, since the purpose of the central spondylodease operation is to place the strong bone graft in the position most biomechanically advantageous, so that the spine can effectively withstand vertical loads. If you use the experience obtained in the surgical treatment of scoliosis patients, should spread along the line of the center of gravity from top to bottom, i.e. And the upper and lower ends of the block area must lie on the same line.

Congenital kyphosis is most rigid in its central part, the para-gambar sections are more mobile. The length and boundaries of these areas (rigid and mobile) can be determined on a spondylogram made in the position of hyperextension. Ventral spinal fusion should capture the entire zone of structural changes, but it should not reach the terminal vertebrae if the center line of the center of gravity passes dorsally to the spondylogram in the position of the hypersensitivity. The posterior bone block should reach the center of gravity line, even if it is far from the terminal vertebrae of the kyphotic arch. After anteroposterior spondylodesis, a single bone conglomerate is formed, the ends of which lie along the line of the center of gravity.

Congenital kyphosis II tila (on the basis of segmentation anomalies)

[13], [14], [15], [16], [17], [18],

Early treatment

In young children, the basis of treatment is a slowdown in the growth of the posterior parts of the vertebrae. Until the gross kyphosis developed, the operation of choice is the posterior bilateral spinal fusion. Its length is one normal vertebra above and below the zone of the anterior congenital block.

[19], [20], [21]

Later treatment

Correction of the formed deformation is a very difficult task. It is necessary to osteotomize the front block at the levels corresponding to the disappeared disks. Experience shows that usually these levels can be determined by spondylograms or intraoperatively - by the elements of fibrous rings. Next, interbody fusion and dorsal spondylodesis using modern segmental CPI instruments or its analogues are performed.

Operation Tomita

In 1994, a group of Japanese orthopedists led by K. Tomita developed and implemented an operation called "total spondylomectomy". The authors proceeded from the assumption that the usual two-stage intervention on the anterior and posterior parts of the spine does not allow obtaining a sufficient degree of correction due to the rigidity of the thorax.

The operation consists of two stages: a single block resection of the posterior vertebral element, resection with a single block of the anterior column.

I stage. Resection of the posterior parts of the vertebrae.

Access. The patient is in the abdominal position. A linear median incision over the length of the necessary for future reliable fixation of the spine with the Cotrel-Dubousset instrumentation. The paraspinal musculature is laterally displaced with the outcrop of the articular joints and transverse processes. At selected levels, the ribs are crossed 3-4 cm lateral to the rib and transverse articulations, after which the pleura on both sides is carefully separated from the vertebral bodies. To expose the upper articular processes of the upper of the removed vertebrae, the spinous and lower articular processes of the adjacent vertebra are osteotomized and removed together with the yellow bunch.

Introduction of a conductor for a flexible saw. Extremely careful not to damage the spinal root, separate the soft tissues from the lower part of the rar interarticularis. In this way, the entrance for the conductor of the saw is prepared. Then a flexible C-shaped curved conductor is inserted into the intervertebral foramen in the craniocaudal direction. The tip of the guide must then move along the medial closure plate of the half-bow and root of the arch, so as not to damage the spinal cord and spine. Finally, the tip of the guide appears below the lower edge of the pars interarticularis. Then a thin flexible multifilament wire saw with a diameter of 0.54 mm is passed through the conductor, and its ends are fixed with grippers. The conductor is removed, the saw is pulled, this tension is supported.

Crossing the roots of the arch and resection of the posterior elements of the vertebrae. Continuing to pull the saw, it is placed below the upper articular and transverse processes around the root of the arch. The latter is crossed by swinging saws at all necessary levels. After that, the posterior elements of the vertebrae are removed by a single block, including articular, awned, transverse processes and roots of the arch. To maintain the stability of the spinal column, the upper and lower "knees" of the kyphosis are fixed with the CDI instrumentation.

II stage. Resection of the anterior column of the spine.

Dull selection of vertebral bodies. At the beginning of this stage, it is necessary to identify segmental arteries from both sides. The spinal branch of the segmental artery running along the spinal root is ligated and intersected. In the thoracic spine, the spinal cord is crossed on the side through which the spinal column elements are supposed to be removed. The blunt selection continues in the anterior direction between the pleura (or m. Psoas major) and the vertebral bodies. Usually, the lateral surfaces of vertebral bodies are easily exposed with a curved spinal trowel. Then it is necessary to separate the segmental vessels from the vertebral body - arteries and veins. Further, the aorta is carefully separated from the anterior surface of the vertebral body with a spatula and fingers. The back surface of the finger of the left hand of the surgeon senses the pulsations of the aorta. When the fingertips of the right and left hands of the surgeon meet on the front surface of the vertebral body, use a series of spatulas of various sizes, which are injected sequentially (from a smaller one) to enhance access. The two largest spatulas are held between the vertebral bodies and internal organs to prevent damage to the latter and to obtain maximum freedom of manipulation.

Conducting a wire saw. Two such saws are inserted at the levels of the proximal and distal sections of the anterior column of the spine. The correctness of the selected levels is specified with the help of marking radiography, in the bone tissue, small incisions are made by the chisel, so that the saw does not move.

Liberation of the spinal cord and removal of the elements of the anterior column. With a thin spatula, the spinal cord is mobilized from the surrounding venous plexuses and ligaments. Then a protector is introduced, which is provided at the edges with teeth, to prevent the saw from slipping. With the help of the latter, the front vertebral column with longitudinal ligaments is crossed. Then, check the mobility of the excised segment to ensure that the intersection is complete. The excised fragment of the anterior column is rotated around the dural sac and removed.

Correction of kyphotic deformation. The CDI tool rods are crossed at the top of the deformation. The formed fragments, each of which is fixed to one of the "knees" of the kyphosis, are connected in the deformation correction position by connectors of the "domino" type. During the correction, the dural bag is under constant visual control. Correct calculation of the necessary volume of resection of the anterior and posterior columns of the spine will allow, as a result of correction, to achieve closure of the bony surfaces of the vertebral bodies and restore the continuity of the posterior wall of the spinal canal. If this is not possible, before the correction stage it is necessary to fill the front "empty" space with an implant such as cage or allocation. It is compulsory to perform posterior spinal fusion with autografts or throughout the CDI toolkit.

Postoperative management. The patient is allowed to get up and walk a week after the operation. Then prepare a hard corset for the thoracic and lumbosacral spine, it should be worn for 6 months.