RU2587643C1 - Method of surgical treatment of thoracolumbar scoliosis - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to traumatology and orthopaedics and can be applied for surgical management expressed S-shaped scoliotic spinal deformities. At one side of deformation installed composite longitudinal consisting of two short rods, external surfaces of opposite end parts of which contain mating parts of connector, rods are bent accordingly deformed into and lumbar parts, depending on the available rotary displacement. One performs antirotation maneuver. Achieved position is fixed with nuts of osteopathic retainer. Parts of connector are connected. Long rod is installed on the opposite side of the spinal column. Composite lengthwise rod is replaced with the long rod.

EFFECT: method enables improving the anatomic and functional clinical outcome.

1 cl, 7 dwg

Description

The invention relates to medicine, namely to traumatology and orthopedics, and is intended for surgical treatment of rigid and severe scoliotic spinal deformities.

A known method of transpedicular fixation of the vertebral segment according to Catrel-Dubosset [1,2]. This method of correction of deformation and fixation of the spine is carried out by applying osteofixes (transpedicular, pedicular screws, laminar hooks) to the vertebrae, installing longitudinal rods in them, curved according to the physiological bends of the spine (lordosis, kyphosis), followed by correction of the deformation of the spine. This correction is achieved by rotating 90 ° of the longitudinal rods installed in the osteo-fixators, while both the correction of the S-shaped deformation of the spine and the formation of physiological bends of the spinal column (lumbar lordosis, thoracic kyphosis) occur. The final elimination of deformation is achieved by distraction along the concave side of the deformation and compression on the convex side due to the instrumental movement of the osteo-fixators along the longitudinal rods (Fig. 1, 2). The system has proven itself only from the best side when performing the intervention on mobile forms of scoliosis, however, its use in surgical treatment of severe scoliotic spinal deformities (more than 90 ° in the standing position) is difficult, due to the technical difficulties of its installation. The longitudinal rods formed at physiological angles (lumbar lordosis, thoracic kyphosis) have angles several times smaller than the angles on the scoliotic arches in the thoracic and lumbar spine (with severe S-shaped scoliosis). This leads to an excessive effect on individual transpedicular osteofixers when installing longitudinal rods, which can cause the osteofixators to tear out or migrate and the entire spinal implant to become unstable. In addition, it is sometimes impossible to achieve the required rotation volume of a long concave rod, which usually happens with very pronounced deformations - more than 90 ° in a standing position and more than 60 ° with lateral tilt. In these cases, with rigid and large deformations, it is recommended to carry out the correction using the Cotrel-Dubousset (CDI) instrument as follows. Two rods are mounted on the concave side. The first, short, fitted to the apical zone, is attached with closed hooks to the upper and lower intermediate vertebrae and an open hook to the apex of deformation on the concave side (Fig. 3). The short shaft is rotated as far as possible, then a second, longer shaft is mounted. It is attached to the selected upper end vertebra with a pedicular hook and to the selected lower end vertebra - laminar. The second rod can be rotated if its lower end is fitted to lordosis to restore lordosis in the patient. Two rods are connected by two transverse DTT plates working for compression. The third rod is mounted on the convex side to the terminal and one or two vertex vertebrae. The long concave and convex rods are connected by two transverse DTT plates near the end vertebrae [3]. This method in its technical solution is the closest to the proposed method.

However, the disadvantage of this method is not only the use for the correction of severe deformation of hook osseous fixators, characterized by instability of fixation and loss of correction in the postoperative period, but also the installation of a short rod with only three hooks, followed by an attempt to rotate, and force, when compressing with two transverse plates (DTT ) between the short and long shaft on the concave side of the deformation. This can lead to the pulling out of the short rod hooks, since the force exerted on the osteofixers created during rotation and compression of the curved short rod from the capsule-ligamentous apparatus of the deformed spine and paravertebral muscles is much more significant than the fixation and reposition capabilities of the short rod mounted on 3 hook osteofixers.

The essence of the invention lies in the combination of distinctive features sufficient to achieve the desired technical result, which consists in achieving correction of spinal deformity in three-dimensional space while reducing the invasiveness of surgical intervention while reducing the time of surgery, while improving the anatomical and functional outcomes of treatment.

The essence of the method of surgical treatment of pronounced S-shaped scoliotic deformities of the spine involves performing dorsal access, installing osteofixes on both sides of the spine at the level of the deformed segments, with fixation on the longitudinal rods, with pre-modeled bends at physiological angles at the level of lordosis and kyphosis, performing axial rotational maneuver rotation of the longitudinal rods by 90 ° and the final correction of deformation due to distraction and compression, moving osteofixato ditch along the longitudinal shaft. On one side of the deformation, a composite rod is installed, consisting of two short rods, on the opposite end sections of which there are bushings containing mating parts of the connector. The rods are bent according to the physiological angles of the thoracic and lumbar regions. Depending on the available rotational displacement, a deerotation maneuver is performed, the achieved position is fixed with osteofixer nuts. Connect the parts of the connector. A long shaft is mounted on the opposite side of the spine. The composite shaft is replaced with a long shaft.

In the absence, or lack of expression, of a rotational displacement of the secondary deformation arc, a short rod does not perform a rotational maneuver, but sets in a rod curved in the shape of the lumbar lordosis.

The connector is made in the form of a threaded connection, the counterparts of which - a screw and a union nut - are placed on the longitudinal axes fixed with racks on the corresponding bushings. In this case, the screw of the connector has a conical longitudinal cavity. The union nut is freely mounted on the corresponding longitudinal axis, it covers the guide located on the end of the axis and turned towards the screw. The guide has a conical shape, in shape and size corresponds to the cavity of the screw, and its base is made spherical.

Installation, on one side of the deformity, of a longitudinal composite rod, consisting of two short rods, bent respectively in the thoracic and lumbar deformed parts, is performed with pronounced arches of spinal deformity. This technique was used to conduct an isolated correction of deformation, which is technically much simpler than its simultaneous implementation using a long longitudinal rod. The fixation of the longitudinal rod in the osteofixers begins from top to bottom. In this case, the greatest difficulty is represented by areas with pronounced apexes of deformations, namely, areas of the thoracic and lumbar scoliotic arch. With a violent attempt to install a longitudinal rod, migration (stretching, pulling, displacement) of already inserted osteo-fixators is possible. The more pronounced the scoliotic arches of the spine, the more difficult it is to carry out this stage of the operation. Therefore, to simplify the installation of the longitudinal rod, it is performed in the form of two interconnected curved short rods installed respectively in the thoracic and lumbar deformed spine.

Performing a derotational maneuver on longitudinal rods, depending on the existing rotational displacement, is necessary to eliminate this displacement of the vertebrae during scoliosis. Isolated derotational maneuvering in the thoracic and lumbar spine provides a more accurate elimination of vertebral rotation, as the direction and severity of rotational displacement with various forms of scoliosis can be different.

Fixing the achieved position of the correction of deformation by nuts of osteo-fixators does not imply a final correction of scoliotic deformation. This is only a partial correction, reducing the degree of deformation to a state in which, without technical difficulties, it is possible to install a long longitudinal rod on the opposite side of the spine.

In the absence, or lack of expression, of a rotational displacement of the secondary deformation arc, the installation of a rod curved in the shape of an anatomically determined lumbar lordosis ensures its formation.

The connection of these rods with a connector ensures the continuity of two curved short rods, connects them into one long longitudinal rod and aims to reduce the degree of scoliotic deformation of the spine to install the final implant in the form of a long longitudinal rod on the opposite side of the spine.

The installation of the connector parts on the axles mounted on the uprights, which are placed along the axis on the outer surface of the bushings, does not interfere with surgical procedures.

The cone-shaped longitudinal cavity of the connector screw is intended to facilitate connection with a flare nut covering the cone-shaped guide located on the axis end, facing the screw and having the shape and dimensions corresponding to the screw cavity during the operation.

The union nut, freely mounted on the longitudinal axis, is displaced, releasing the end of the guide by pressing on the ribs of the patient from two sides, the guide is inserted into the screw cavity. A nut that can move along the spherical surface of the base provides a connection to the screw.

The manufacture of a screw with a conical longitudinal cavity, the free installation of a union nut on the axis, at the base of the spherical shape of the cone-shaped guide, in the shape and dimensions of the corresponding cavity of the screw, makes it possible to insert the end of the guide into the cavity of the screw and tighten the connection with a nut, which allows you to connect the axis of short curved rods.

The free installation of the nut on the axis with the possibility of its movement on the surface of the spherical base of the cone-shaped guide, provides a deviation of the axis of the nut from the longitudinal axis, facilitates the implementation of threaded connections, because Before tightening the connector, connecting its parts, the axes of the installed short curved rods may not match. The connection of two short rods in a position partially offset from the existing deformation allows you to select the required length of a long longitudinal rod more accurately, since regular longitudinal rods have a standard length without bending. The surgeon himself, itraoperatively, forms the length of the pliers, and his physiological bends, depending on the form of scoliosis and its length, forms with a special tool - a bending rod, from a standard set of tools.

Installation on the opposite side of the spine of a long rod is necessary to fix the spine in a position partially offset from the existing deformation. The installation of this rod makes it possible to dismantle the short rods with the connector of the composite rod and install a standard long longitudinal rod instead.

The method is illustrated by the illustrations.

In FIG. 1 shows a diagram of a method for transpedicular fixation of the spinal segment according to Catrel-Dubosset;

In FIG. 2 - implant used for transpedicular fixation of the vertebral segment according to Catrel-Dubosset;

In FIG. 3 - installation diagram of the Catrel-Dubosset implant according to Mikhailovsky with rigid and large deformations;

In FIG. Figure 4 shows a diagram of an S-shaped scoliotic spinal deformity with installed transpedicular osteofixers in the form of screws 1. Short, curved, shaped according to the physiological angles of lumbar lordosis and thoracic kyphosis, rods 2 and 3 are superimposed on the scoliotic arches in the thoracic and lumbar region;

In FIG. 5 shows a diagram of a deformed spine after a derotational maneuver carried out on short curved rods; partial correction of spinal deformity is achieved;

In FIG. 6 is a diagram of the spine, where installed short rods are connected by a connector 4; on the opposite side of the spine a regular long longitudinal shaft 5 is installed;

In FIG. 7 shows the components of the connector 4, where the screws 10 and the union nut 12 of the connection forming the connector 4 are respectively fastened to the bushings 6 and 7 with the help of the struts 8 and 9. In this case, the screw 10 has a conical longitudinal cavity 11 and is mounted with its axis on the rack 9. The nut 12 is freely mounted on the axis of the cone-shaped guide 13, the shape and dimensions of which correspond to the cavity 11 of the screw 10, and its base 14 is made spherical. The conical end of the guide 13 is inserted into the cavity 11 of the screw 10 and tightened with a nut 12.

The method is as follows.

After dorsal access is performed, osteofixers are installed in the form of transpedicular screws 1 on both sides of the spine at the level of the deformed segments, with fixation on short longitudinal rods 2 and 3 with pre-modeled bends at physiological angles at the level of lordosis and kyphosis. Short longitudinal rods 2 and 3 are fixed on osteo-fixators 1 with standard nuts (Fig. 8), without tightening the latter until the end, so that it is possible to perform a derotational maneuver by axial rotation of these rods by 90 °. After performing the derotational maneuver, these rods are connected using the connector 4 as follows. On the ends of the short longitudinal rods 2 and 3, the sleeves of the connector 6 and 7 are put on, on which, using the racks 8 and 9, the axes of the parts of the screw connection forming the connector are fixed. The screw of the connector 10 has a conical longitudinal cavity 11. The nut 12 is freely mounted on the axis of the conical guide 13, in the shape and dimensions of the corresponding cavity of the screw 10. The base 14 of the guide 13 is made spherical. By pressure on the patient’s ribs, the end of the guide 13 is led to the conical longitudinal cavity 11 of the screw 10. The union nut 12, freely mounted on the axis of the guide 13, is moved along the spherical base 14 of the guide 13 until the screw connection is baited - the screw and nut are first connected with the first threads. When tightening (screwing) the union nut 12, the end of the cone-shaped guide 13 is “drawn” into the longitudinal cavity 11 of the screw, while the axes of the short curved longitudinal rods 2 and 3 are connected. On the opposite side of the spine, a regular long rod 5 is installed, after which the short longitudinal rods connected by a connector are replaced with a second regular long longitudinal rod.

The final correction of the deformation is carried out by distraction and compression by moving the osteofixes along the longitudinal rods using standard tools - a distractor and a compressor - from a set of tools. The operation ends with the connection of long longitudinal rods with two transverse plates (DDT) to give the implant system a rectangular closed configuration.

Information sources

1. Dante G. Marchesi and Max Aebi, Pedicle fixation devices in the treatment of adult scoliosis, Spine, 1992, N 8.

2. C-D instrumentation in spine surgery. Principles, technicals, mistakes and traps. Souramps Medical, 11 boulevard Henry IY-Montpellier. 1992.15 p.

3. M.B. Mikhailovsky, N.G. Fomichev. Surgery of spinal deformities Novosibirsk, 2011, p. 217, fig. 7.52.

Claims (1)

A method of surgical treatment of severe S-shaped scoliotic spinal deformities, including dorsal access, installation of osteofixes at the level of deformed segments with fixation on longitudinal rods, with pre-modeled bends at physiological angles at the level of lordosis and kyphosis, performing a derotational maneuver, characterized in that on one side of the deformation, a composite longitudinal rod is installed, consisting of two short rods, the outer surfaces of the opposite end sections which contain mating parts of the connector, the rods are bent according to the deformed thoracic and lumbar, depending on the existing rotational displacement, perform a deerotation, fix the position achieved with osteofixer nuts, connect the parts of the connector, install a long shaft on the opposite side of the spine, and replace the composite longitudinal shaft long shaft.

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