Scoliosis: operation

Scoliosis: operation endorrector Harrington (I generation)

Harrington began work on creating his endocorrector in 1947 with the study of anatomy and deformities of the spine. The author made a conclusion about the principle possibility of obtaining and retaining the correction of the scoliotic spine with the help of a metal structure and in the period from 1947 to 1954 applied it in 16 patients. For 5 years Harrington has created 35 (!) Modifications of its endorsementor. In 1955-1960, 46 patients were operated on and 12 additional instrument modifications were developed.

The device consists of several components made of stainless steel. It is designed to apply a corrective force to the scoliosis of the spine using a distractor on the concave side and the contractor on the convex, and, when necessary, stabilizing system fixed to the crests of the iliac bones. At the lower end of the distractor there is a 3/4 inch section, narrowed according to the diameter of the opening of the lower hook, at the upper end there are several circular grooves in such a shape that the upper distraction hook slightly tilts and engages in one of the grooves, so that it can not slide down on the rod, when the distraction axial load acts on the hook. The contractor consists of a threaded rod, hooks with axial holes and hexagonal nuts. The sacral support is a threaded rod, one end of which is pointed for drilling.

Harrington operation technique

Anesthesia is endotracheal. The patient is placed on the stomach. The spine is subperiosteally exposed to the tips of the transverse processes. Specify the location of the hooks of the distractor. For the upper hook, a cut is made in the lower articular process of the selected vertebra. The bottom hook is always placed in the lumbar region. Then, places are being prepared for the installation of the hooks of the contractor. Each hook is grasped with a special tool and "cut" at the base of the corresponding transverse process as close as possible to the root of the arch. Lower hooks (usually in the lumbar region) are inserted under the arch or under the apex of the lower articular process of the selected vertebra. Then insert the terminal of the contractor and tighten the hexagonal nuts.

The distraction rod is guided through the opening in the upper hook and cranial direction, until the lower edge of the rod is restrained and the lower hook. Then, the lower end of the rods is inserted into the aperture of the caudal hook and the distraction is initiated with a spreader. At the end of the distraction, the position of the hooks should be checked. The surgeon works as a distractor and a cantutor sequentially until both instruments are in a state of tension. Then the posterior spondylodesis is performed, the wound is layer-by-layer closed.

In some cases, there is a need to stabilize the position of the lower-vertebral segments. To do this, use a lower transverse support rod. Access is extended to the sacrum: the sharp end of the transverse stem allows it to pass through the posterior parts of the iliac bones, and the slicing makes it possible to hold the correct direction of the exercise. On one side of the rod there is a flat platform for preventing torsional displacement caused by the hook of the distractor, which is supported by this rod.

After 10-14 days, remove the stitches, make a well-modeled gypsum corset for 4 5 months.

One of the most famous modifications of the broom was developed by V. Cotrel. The system is a short rod-contractor, which is fixed on the convex side of the deformation, in the region of its apex, and attached to the transverse processes of the vertebrae. The contractor is connected to the distractor by a transverse rod with a thread, which makes it possible to bring both bars closer, bringing the deformation peak closer to the midline of the trunk. In addition, the use of the modification Y. Cotrel allows to form a rigid framework rectangular structure, significantly increasing the degree of fixation of the achieved corrective effect,

Complications after surgery on scoliosis

Fractures and displacements endocorrector. The frequency of this complication varies from 1.5 to 46%. The main reasons for the complication are a lack of autopsy when performing a spondylodease, an age older than 20 years, a strain value of more than 90 °.

False joints. This concept, introduced into vertebrology from classical traumatology, means the absence of a single continuous bone block in one or more places throughout the area of the spondylodease. The causes of this complication are various: the errors of the surgical technique, a small amount of autonomy, the general condition of the patient, the etiology of deformity of the spine. Analysis of the literature showed that the purity of this complication is 1.6%,

Neurological complications are the most serious complications. The frequency of their development using the Harrington method is 0.7-1.2%.

Postoperative pain syndrome and flat back syndrome. The problem of the state of a segment of the spine located caudal to the lower hook of the distractor arose in the 1980s when patients who were operated 10 to 15 years ago reached adulthood. Many of them again turned to the orthopedist with complaints of pain and lower back. Clinical radiology examination revealed a picture of lumbar osteochondrosis.

The use of the Harrington distractor and the scissors can lead to another, very undesirable, effect of the symptom-comolex of the flat back. It happens as a result of the installation of the caudal hook at the L5 or S1 levels and consists in smoothing up to the complete disappearance of the lumbar lordosis. Clinically, this is manifested by pain in the back and inability to stand, as the patient's torso leans forward.

Cast-syndrome. The term was introduced in 1950 Darph. This is the result of mechanical compression of the third portion of the duodenum by the trunk a. Mesenterica superior. The term is not entirely accurate, as the development of the described symptom complex can be caused not only by corrective corsets, but also by distraction by Harrington.

Normally the third horizontal portion of the duodenum starts at the level of the body L4, goes to the left and at the level of the body of the vertebra L2 passes into the fourth part. The upper mesenteric artery departs from the aorta at an angle, the average value of which is 41 °. A horizontal portion of the duodenum passes between the aorta and the vertebral body from behind and a. Mesenterka superior - front. Thus, conditions are created for squeezing the duodenum in any situation, when the angle of divergence a is narrowed. Mesenterica superior, the duodenum is displaced or the space between these formations is narrowed.

The main symptom is persistent nausea and vomiting in the early postoperative period, bloating. Acute metabolic alkalosis can develop. It is possible to develop oliguria and rupture of the stomach wall. Radiocontrast study reveals the expansion of the stomach and duodenum.

Treatment of scoliosis is conservative. Oral nutrition is discontinued, a gastric tube is used, and intravenous fluids are administered. The position of the patient is on the left side or on the abdomen, sometimes this is enough for the disappearance of pathological symptoms. With the increase in symptoms, you need to remove the corset, stop the traction, enter the glucocorticoids. If these measures do not have an effect, then duodenojunostomy is indicated. The complication rate is 0.17%,

General surgical complications. Suppuration of the operating wound develops in 1.1% of cases and does not always become an excuse for removing coroners. In time, the installed flow drainage allows to save the tools and to keep the correction achieved.

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

Two-stage method of correction of scoliosis according to Ya. Tsivyanu

A significant loss of correction is noted after the distraction by Harrington almost always. The analysis of the situation led to the conclusion that such a loss of correction is quite natural. The Harrington distractor (most surgeons do not use the contractor) is fixed to the spine at only two points, in the interval between the hooks a posterior spondylodeasis is performed. Works of the school Ya.L. Tsivyan convincingly showed that this operation on scoliosis is not able to withstand the progression of deformity of the spine. The etiology of idiopathic scoliosis is still unknown, but it is obvious that the causes of the deformation progression continue to exert their influence in the postoperative period. The increase in the scoliotic arch is the increase in the torsion of vertebral bodies in the first place. It is the progression of the torsion component of deformation that is regarded as a loss of correction, although it would probably be more correct to talk about the progression of the pathological process under the new conditions.

The necessity of interrupting this process Ya.L. Tsivyan realized as early as the early 1960s when he did not have such an effective tool as the Harrington tool. In the mid-1970s, Ya. L., Tsivyan developed a di-stepped method of surgical treatment of scoliosis, which included distraction by Harrington and ventral spinal fusion of the main arc. A later analysis of the results showed that ventral spondylodesis more than triples the postoperative loss of correction.

Scoliosis: operation endocorrector Luque (II generation)

This endocorrector was created by the Mexican orthopedist Edwardo Luque in 1973. The method provides correction and rigid segmental fixation of the spine with the help of two rods and sublaminarly conducted wire loops.

Technique of operation

The patient's position is on the abdomen, while the spine is bent and the side of the convexity of deformation (this is achieved by passive correction).

Skeletal posterior parts of the vertebrae throughout the entire deformation. On both sides, remove facet joints, excise yellow ligaments. And the areas of the thoracic spine resect the spinous processes. Determine the necessary length of the spondylodease, then prepare the rods, depending on the size of the patient. It is recommended to bend the rod to an angle of 10 ° less than the amount of deformation in the spondylogram in the lateral incline position. In the same way, the rod should repeat the form of kyphosis or lordosis. The normal values of these physiological curves should be preserved or restored, if initially they were smoothed. Each core should have names, at the end an L-shaped bend, with which it will be fixed to the base of the spinous process of the terminal vertebra through the transverse aperture to prevent longitudinal displacement of the rod.

Wire loops are carried out under the arches at all levels of the spondylodease zone in the cranial direction. While reducing the depth of penetration of the loop into the spinal canal, the wire should be bent so that the radius of the bend is approximately wounded by the sum of the width of the arch and both adjacent interstitial spaces. When the loop appears in the upper interstitial space, it is firmly grasped with the tool and dissected. It turns out two pieces of wire to the right and left of the middle line. The placement of the rod begins with the introduction of its terminal bend into the hole in the base of the spinous process. Then the first wire fix it to the half-bug of the same vertebra. The second rod is fixed similarly on the other koin of the spondylodease zone, on the opposite side. The rods are laid on the half-bows, each of the wires are tied over them and partially tightened. As the wire is tightened, the rods are pressed against the meadows, the deformation is gradually corrected. Then the rods are connected to each other on several levels by additional transverse wire loops, sublaminar wire loops are tightened as much as possible. Perform dorsal spondylodesis,

In 1989, the author of the method reported on a significant improvement: we are talking about hooks that are fixed on rods and take on compressive and tensile loads. The method does not provide for external immobilization, and the period of bed rest is only 1-2 weeks.

Complications after surgery

The implantation and spinal canal of a number of wire loops increases the risk of neurologic complications to 2.92%. Suppuration with the Luque method was noted in 3.27% of cases, false joints in the block - in 3.0%, violation of the integrity of the system - in 6.8%.

Segmental correction using the bases of spinous processes (J. Resina, A. Ferreira-Alves)

The first report on the correction of scoliotic deformities using the bases of spinous processes as support structures was dated 1977. Later the method was refined and modified by Drumraond et al. A serious justification for the method was the calculations of Druminond et a, which showed that the thickness of the base of the spinous process exceeds the thickness of the adjacent sections of the arch in the thoracic spine at 2.2. And in the lumbar - in 1,7 times.

Techniques for the operation of Resina and Ferreira-Alves in the modification of Drummond. The posterior parts of the vertebrae are exposed at the required length in a manner similar to the manipulation in the Harrington operation. Install the Harrington distractor hooks and begin to conduct the wire loops through the bases of the spinous processes. Preliminary perform microarthrodesis of true joints. For the implantation of wire loops, first a special curved stitches form transverse channels in the bases of the spinous processes.

At the level of the upper and lower hooks, the wire loops are carried only from the concave side to the convex side. On the other levels, two loops are carried out in such a way that one goes out on the concave side and the other on the convex side of the deformation. Each wire loop is preliminarily carried through a round metal "button" that densely lies on the lateral surface of the spinous process. The ends of each loop must pass through both "buttons". The distraction is then carried out with Harrington. On the convex side, install the Luque rod. The wire loops are tightened first over the Luque, then over the Harrington. Both bars are attracted to each other in addition by transverse wire loops. In the previously formed bone bed, autografts are placed, the wound is layer-by-layer closed. External immobilization in most cases is not used.

[6], [7], [8], [9], [10],

Instrumentation Cotrel Dubousset (III generation)

The toolkit was developed and first applied in 1983 by French orthopedists Yves Cotrel and Jean Duboussel. The toolkit contains the following elements:

Rods of uniform diameter, not having weak points and capable of bending at any place without loss of mechanical strength, to which hooks can be fixed in any place;

Hooks for various purposes (laminar, pedicular, transverse), providing a corrective force in the required direction,
Devices for transverse traction, connecting the two bars and a rigid frame structure.

The basis of the theoretical concept of Cotrel-Duboussel Instrumentation (CDI) is as follows; scoliosis - a three-dimensional deformation of the spine, therefore, its correction must be carried out in three planes.

The technique used by CD HORIZON in the typical case of thoracic lordoscoliosis with lumbar antiscovering

Principles of pre-operational planning

The goal of surgical treatment of adolescent idiopathic scoliosis is to prevent progression in combination with safe and optimal correction in the frontal and sagittal planes and axial dystonia. At the same time, it is necessary to maintain the maximum number of free motor segments above and below the zone of the spondylodease.

Upper border of the spinal fusion zone

The most common is a single thoracic scoliotic arch with white upper antrumediation. With such deformations, the upper end of the spinal fusion zone becomes the cranial terminal vertebra. Mobility of the upper thoracic spine is determined in the lateral tilt position towards the convexity of the upper thoracic anticoagulation - measure the angle Cobb between the caudal plate of the upper vertebra of the arch and the cranial plate Th1. Then the mobility of the cranial part of the main arc of curvature is investigated - on the spondylogram in the lateral slope position in the direction of its convexity. Here, the angle formed by the caudal closure plate of the apical vertebra and the cranial closure plate of the upper terminal vertebra of the primary arch is measured. To maintain the balance of the shoulder straps after the operation, the difference between the two above-mentioned angles should not exceed 17 °. When determining the cranial border of the zone of spinal fusion, a profile spondylogram should be carefully examined - the upper hooks of the structure should not be located at this level or 1-2 segments and distal.

Lower border of the spinal fusion zone

The definition of this boundary is one of the most difficult tasks in scoliosis surgery. The need to preserve the maximum possible number of free motor segments in the lower-lumbar spine is dictated by two circumstances.

The shorter the zone of the block, the easier it is for a patient to adapt to new conditions of statics and dynamics in the postoperative period.

The shorter the zone free from the block, the greater the probability of early degenerative changes in the overloaded lumbar intervertebral discs.

The most cranial of the remaining free segments should be balanced in three planes. For the equilibration in the frontal plane, the most cranial disc from among the located caudal units should symmetrically "open" to the right and to the left.

For balancing in the sagittal plane, the cranial disc of the number below the zone of the block should be included in the correct flat
Sagittal curvature of the spine in a standing position. In addition, the disc should be balanced with flexion and extension compared to the standing position at rest

In order for this disk to be balanced in the horizontal plane, it must be theoretically free of any residual permanent twisting loads.

To determine the extent of the zone of instrumental spondylodesis, several classifications of idiopathic scoliosis have been created, the most complete of which is the development of Lenke el al.

According to the classification of Lenke et al. Six types of deformation are distinguished, and two modifiers are introduced to characterize the lumbar arch and the sagittal profile of the thoracic spine. The lumbar modifier is designated as A, B or C, and the chest modifier is designated as (-), N, or (+).

The type of deformation (from I to VI) is determined in accordance with the recommendations of the Scoliosis Research Society.

• To thoracic scoliosis (the vertex between the body of Th2 and the disk Th11-12) is the proximal or upper thoracic (the vertex at the Th3, Th4, Th5), and the main ones (the vertex between the Th6 body and the Th11-12 disc).
• The top of the thoracolumbar scoliosis lies between the cranial closure plate Th2 and the caudal plate L1.
• Lumbar scoliosis has a vertex between the LI-2 disc and the caudal closure plate of the body L4.

A structural scoliotic arc is considered when the usual mobility is lost and, depending on the magnitude of the angle, Cobb is called the major or secondary arc.The secondary arc can be both structural and nonstructural.For the ease of using the classification, specific characteristics of the structural arcs were introduced.

• The structural upper thoracic curvature in the lateral slope position has a Cobb angle of at least 25 ° and / or kyphosis of at least 20 ° from Th1 to Th5.
• The primary thoracic structural arch also in the lateral incline retains a minimum of 25 ° Cobb angle and / or thoracolumbar kyphosis at least 20 ° at the Th10-L2 level.
• Structural lumbar (thoracolumbar) arc is characterized by the same parameters of mobility in the lateral slope and / or presence of kyphosis at least 20 ° at the level of Tp10-L2.

Any secondary arc is considered structural if there are listed characteristics. Lenke et al. It is believed that when planning an operation, only primary and structural secondary arcs should be included in the zone of the block. There are six types of deformations:

• Type I deformation; the main thoracic arch is structural, and the upper thoracic or lumbar (thoracolumbar) anticorrosion is nonstructural.
• Deformation of type II: two thoracic structural arches, and the lumbar (chest-lumbar) antiscavity is nonstructural.
• Deformation of type III: two structural arches - primary thoracic and lumbar (chest-lumbar), upper thoracic antiscavity - non-structural. The thoracic arch is greater, equal to or less than the lumbar (chest-lumbar) not more than 5 °.
• Deformation of type IV: three structural arches - two thoracic and lumbar (thoracolumbar), and any of the latter two may be primary.
• Deformations of type V: structural lumbar (chest-lumbar), more proximally located arcs - non-structural.
• Type VI deformation: the main lumbar arch (chest-lumbar), at least 5 ° more than the thoracic arch, both structural,

Proximal upper thoracic anticoagulation is non-structural.

If the difference between the thoracic and lumbar arcs is less than 5 °, scoliosis is classified as a type III, IV or V strain based on structural characteristics. Always distinguish III (primary thoracic arch) and VI (primary arch - lumbar or thoracolumbar) types. If the value of these two arcs is equal, the primary is considered to be thoracic.

Use of the lumbar modifier (A, B, C)

When planning an operation, it is necessary to evaluate lumbar curvature, since it affects both the vertebral balance and the proximally located arcs. Depending on the ratio of the central sacral line (CCL) to the lumbar arch on a direct spondylogram, Lenke et al. Three types of lumbar scoliotic deformations were identified.

TSKL divides the cranial surface of the sacrum strictly in half and is perpendicular to the horizontal.

The CCL continues in the cranial direction, and the one from the lumbar or lower thoracic vertebra, which this line divides most accurately in half, is considered stable.

If the intervertebral disc is divided into two equal parts, the vertebra, located caudal to this disk, is considered stable.

The vertex of the lumbar (thoracolumbar) arch is considered to be the vertebra or disk, located most horizontally and most shifted laterally.

Depending on the ratio of the CCL to the lumbar arch, different modifiers are used.

Modifier A is used when the CCL passes between the roots of the lumbar vertebrae to the level of the stable vertebra. Such scoliosis should have a vertex at the level of the Th11-12 disk or cranial, that is, the A modifier is used only for thoracic scoliosis (I-IV types), but not for the lumbar and thoracolumbar (V-VI types). Similarly, it is not used when the CCL passes through the medial edge of the shadow of the root of the arch of the apical vertebra.

Modifier B is used when, due to the deviation of the lumbar spine from the midline of the DCL, the apex of the lumbar arch is between the medial edge of the shade of the apical vertex arch and the lateral edge of its body (or bodies, if the vertex is at the disk level). Such scoliosis, as in the case of the A. Modifier, is referred to as II-V types.

Modifier C is used when the CCL lies completely medially with respect to the lateral surface of the body of the apical vertebra of the lumbar (thoracolumbar) arch. Such scoliosis may have a primary arch of the thoracic, lumbar or thoracolumbar locus. The modifier C can be used for any chest scoliosis (II-V types) and should be used for types V and VI (lumbar and thoracolumbar scoliosis).

Sagittal breast modifiers (-, N, +)

The sagittal contour of the thoracic spine should be taken into account when planning surgical intervention. The type of modifier is determined by measuring the sagittal contour Th5-Thl2 in the patient's standing position. In the presence of kyphosis less than 10 ° (hypokyphosis) modifier (-) is used, from 10 to 40 ° modifier N, with a deformation of more than 40 ° (hyperfix) - modifier (+).

Thus, by treating the scoliotic deformity to one of the six types, having determined the lumbar and thoracic modifiers necessary in this case, it is possible to classify scoliosis in a compressed form, for example IА-, IAN, 6CN, etc.

The structural characteristics of deformation in the sagittal plane play an important role in the Lenke et al. System, since the length of the spondylodesis zone, the hyperkophosis of the upper thoracic and thoracolumbar regions and the rigidity demonstrated in the lateral slope position are important characteristics of the so-called secondary deformations. The length of the spinal fusion of the thoracic spine with deformities of types I-IV depends on the increase in kyphosis in the upper thoracic or thoracolumbar regions. For V and VI types of scoliosis, the brick arch is lumbar (chest-lumbar), thoracic antiscavity in type V is unstructured, and in case of VI - structural.

The lumbar modifier A indicates that the lumbar arch is minimal or nonexistent, and the B modifier is for the presence of a light or moderate lumbar arch.

Lenke et al. It is believed that in the presence of A or B modifiers, the lumbar arch should not be blocked unless there is more than 20 ° kyphosis in the thoracolumbar spine. In patients with deformities of type 1C or 2C, it is possible to perform selective thoracic spondylodesis, the length of which allows preserving the balance of the lumbar spine.

Selective thoracic spondylodesis with Type I deformities with any lumbar modifier when using segmental instruments often leads to the development of torso imbalance. However, this operation on scoliosis is possible under the following conditions: lumbar arch in lateral slope position less than 25 °, there is no kyphosis in the thoracolumbar region, thoracic spine is rotated more than the lumbar spine.

Deformations of type IIA (with any breast modifiers) include, in addition to the main thoracic arch, structural upper thoracic and non-structural lumbar (thoracolumbar) anticorrosion. Any structural thoracic or lumbar arch can have structural upper thoracic antiscavity. Structural upper thoracic arches with scoliosis IV type have the same characteristics. Isolation of type IIC allows us to consider the upper thoracic and lumbar components of the deformation separately.

Deformations IIIA and IIIB types (with any breast modifiers) are relatively rare and contain two primary arcs - thoracic and lumbar (chest-lumbar). The lumbar component of this deformation is always structural in the frontal and sagittal planes, even if the arc slightly deviates from the midline. With SC scoliosis of the same type, this deviation is always significant, so both arcs should be included in the block.

Triple scoliosis IVA and IVB types (with any breast modifiers) contain three structural arches: the upper thoracic, thoracic and lumbar (chest-lumbar), the latter two larger than the first. The lumbar arch does not move completely from the midline, but if the thoracic arch is coarsely expressed, the lumbar curvature has signs of structurality. With deformations of IVC type, the deviation of the lumbar arch from the midline is significant, as one should expect.

Lumbar (chest lumbar) scoliosis is referred to as VC if they have unstructured thoracic antiscavity, and to type VIC - if the chest anger has signs of structurality. In any case, only structural distortions are blocked.

Surgery Technique

Patient preparation and packing

To facilitate manipulation of the course of intervention, it is desirable to use traction. In fact, it helps to stabilize the spine, as well as somewhat "weaken" it due to its own elasticity. In addition, the traction facilitates the installation of hooks and rods. The traction should not exceed 25% of the patient's body weight. When laying in the operating position, the abdominal wall should be completely released to avoid compression of the inferior vena cava.

The skin incision is linear median. The preparation of the posterior parts of the vertebrae involves the careful removal of soft tissues throughout the future zone of the flea, the spinous processes, half-arches, articular and transverse processes.

Hook settings

The lower limit of the design. Experience shows that when forming the caudal part of the structure, in all possible cases it is desirable to use a configuration called reverse (reversal) capture. This option gives several advantages: reliable fixation, providing lordoziruyuschey affect during rotation of the rod, cosmetic effect, expressed in the normalization of the shape of the triangles of the waist.

When forming a re-engagement, only laminar hooks of different types are used. First, two hooks are implanted on the side of the correcting rod (for right-sided scoliosis - on the left). The installation of the infralaminal hook on the terminal vertebra is quite simple. Yellow bundle with a sharp thin scalpel is separated from the arch to expose its lower edge. In some cases, especially in the lower lumbar spine, the half-brow is very upright, which increases the risk of slipping the hook. In these situations it is better to use an oblique laminar hook. The shape of his tongue corresponds more to the anatomy of the arch.

The second hook (supralaminar) is set to one or two segments more cranial. Installation supralaminar hook (usually a hook with a wide tongue) is technically not much different from infralaminar.

On the opposite side of the lower end of the structure, two hooks of the opposite orientation, supra- and infralaminar, are used in reversible gripping. This makes it possible to more effectively normalize the position and shape of the caudal one of the intervertebral discs included in the spinal fusion zone. The supralaminar hook on the right half of the reversible capture in connection with the torsion of the lumbar vertebra often proves to be very deep, which further complicates the introduction of the lower end of the rod into its lumen. In this regard, it is recommended to use a hook with an elongated body.

Apical and intermediate hooks

The vertebrae, on which these hooks establish, belong, along with the terminal ones, to the number of strategic ones. The usual sequence of implantation of hooks involves the initial formation of a reversible causal capture, and then parts of the design that play a decisive role and the course of the destructive maneuver, these are called intermediate guts located between the apical and terminal vertebrae. The pre-operation spondylogram and the position of the tilt of the main ray and the side of its convexity shows, among other things, the least mobile vertebral segments in the region of the apex of the arc. It is these segments that become the place of implantation of intermediate hooks working in the mode of distraction and therefore multidirectional. The lower of these hooks is supralaminar, the upper one is pediculate. The installation of the supralaminar hook in the thoracic spine requires great care and the connection with the fact that it can occupy a rather large space, its installation is performed without any violence. In some cases, and the quality of the lower intermediate hook, it is advisable to use a hook with a displaced body, which makes it easier later to introduce a curved rod into its lumen.

The upper intermediate hook of the concave side and the apical hook they are quoted on the convex side of the vertex of deformation are pedicular. When installing the pedicle hook, it is necessary to remove the caudal part of the lower articular process of the corresponding vertebra.

The line of the lower edge of the half-bug is very markedly curved, showing the inner crane of the articular process. An osteotome is first performed along the medial edge of the lower articular process, then the second section is parallel to the transverse axis of the vertebral body. This section must be completed, otherwise the hook can migrate and occupy the infraluminal position.

A special tool widens the entrance to the joint, while the surgeon is convinced that the tool is in the joint cavity, rather than exfoliating the rest of the resected articular process. The pedicle finder is used to locate the root of the arch by inserting it into the joint without excessive force. A hook is then inserted by using a gripper and a pusher. For injection, the hook is held in a slightly inclined position with respect to the articular process. With a slight flexion movement of the wrist, the hook is also inserted into the joint cavity, which is more or less parallel to the general inclination of the vertebral body. They carry out manipulation without violence. Correctly installed hook "sits up" on the dorsal part of the root of the arch and cuts into it.

[11], [12], [13], [14],

Upper Construction Limit

To achieve maximum stability, it is advisable to complete the construction with bilateral upper arms. To the level of Th4, pedicular-transverse seizure on one vertebra is used. Cranial Th4 recommend a pelicular laminar occlusion, formed on one, and on two adjacent vertebrae. Without fail, they perform a resection of the arc-process joints and spondylodesis. To reduce blood loss, it is advisable to break this manipulation into two stages and to prescribe each of them the implantation of the next rod.

Bending of rods

The technique of this important manipulation depends on the shape of the spine, which must be obtained as a result of the intervention. The main part of the operation is the destructive maneuver intended to provide a harmonious correction when the corrective force is applied to the entire instrument zone at the same time. The purpose of manipulation is to restore the balance of the spine. When bending the rod, you should constantly monitor its axis, so that the bend occurs only in the required plane. Technically, the rod is contoured using a so-called French flexor.

[15], [16]

Installing the rod on the concave side of the arc

This rod is established first for the correction of the thoracic arc by automatic distraction, which occurs during the rotation of the stem, and to restore the thoracic kyphosis. In the lumbar region, acting on the same principle, the rod restores the lumbar lordosis. The introduction of the rod is facilitated by the presence of open hooks. Correction of the spine begins with longitudinal traction during the operation, then a curved rod is implanted on the concave side and a deroting maneuver is performed.

Standard injection of the stem is initiated at the upper thoracic level. First the rod enters the slot of the pedicle hook, why - in the corresponding transverse hook from the total grip. The locking bushing is screwed into the transverse and pedicle hooks with a free hand by gripping the bushing. The sleeves are tightened a little to fix the hooks of the upper gripper on the rod. Then the rod is inserted into the most distally located hooks. This manipulation (insertion of a rod into intermediate hooks) is the first stage of deformation correction.

Rotation of the rod is carried out by special grippers - slowly and gradually, so that the visco-elastic properties of the spine help to reduce deformation. It must always be remembered that the pedicle hook can potentially move into the vertebral canal and turn into sublaminar, and the lowest
Sublaminar hook can move dorsally and the rotation of the rod. Particular attention should be paid to the position of intermediate hooks, since during the course of the détentation they are exposed to a particularly pronounced effect, which is really capable of damaging the bone structures and displacing the implants. After the end of rotation, all the sleeves are tightened. As a matter of fact, dératation with the help of the first rod is the main corrective manipulation.

Installation of the rod on the convex side of the arc. The role of this rod is to increase the stability of the system and to keep the correction achieved. There are no special differences from the installation of the first rod.

Installation of devices for transverse traction (Device for Transverse Traction - DTT). These devices are installed between the rods in the direction of distraction at the upper and lower ends of the structure, and for a length of the structure of more than 30 cm, in addition to its middle part.

Final tension and cutting of the heads of the bushings. During the cutting of the heads of the sleeves, the hooks are fixed with a special device (counter torque), which excludes the impact on the hooks and underlying torsion forces.

Bone spondylodesis

All available bone surfaces of the planned area of the spinal fusion should be decorticated and included in the block. Instead of removing the articular processes, it is advisable to perform their decortication to increase the area of the bone bed. Experience shows that an economical attitude to local autonomy while preserving the slightest of its fragments in the formation of the hook box and decortication makes it possible to form a bank sufficient to perform a spondylodease in a patient. Muscles and fascia sutured with nodal sutures, set tubular drainage under the muscles for 48 hours

[17], [18], [19]

Postoperative management

The patient is picked up and allowed to walk early - on the third day. The patient must learn to control his new condition in front of the mirror in order to develop new proprioceptive mechanisms. It was noted that after surgery almost all patients experience a feeling of curvature. Therefore, they have a desire to return to their pre-operative state. Using a mirror in this regard is very useful for adapting to a new state.