RU2678467C1 - Method of conducting transpedicular fixation of lower cervical spine - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention relates to the field of medicine, namely, neurosurgery, and can be used when fixing the lower cervical spine from the dorsal access. Perform preoperative multiplanar reconstruction of the vertebra in the axial plane. Based on the data of a computer tomogram, according to which, according to the transpedicular trajectory, the following is determined: length of the screw (a), its thickness corresponding to the thickness of the leg of the vertebra (b), the angle of installation of the screw relative to the midline connecting the middle of the body of the vertebra and the spinous process (c), the distance of indentation in the lateral direction from the midline to make a skin incision (d) and the angle of installation of the C-arc of the x-ray machine relative to the midline for visualization of the leg (e). Then perform skin access markup on the patient's body. For this purpose from the midline corresponding to the spinous processes of the vertebrae, leave some lateral space of value (d), then perform x-rays in the anterior-posterior projection to determine the cranial and caudal border of the skin incision. In accordance with the marking, a skin incision is performed, after which the subcutaneous fatty tissue and the aponeurosis are dissected, the bundles of muscle fibers are moved apart to the lateral parts of the lateral vertebral masses. Next, to the point of insertion of the screws, a port with a spokes guide is installed, which is placed under x-ray control according to the screw installation trajectory at an angle (c). Port is rigidly fixed and under X-ray control with positioning of the X-ray arc at angles (c) and (e) transpedicular to the body of the vertebra establish a Kirchner needle, according to which, after preliminary reaming of the bone canal, a cannulated screw is installed with the parameters (a) and (b) determined at the preoperative stage. Intervention zone is visualized using an operating microscope, for which a small dilator retractor is fed into the screw installation area at a right angle to the line through a previously performed skin incision and expansion of the muscular canal. Wounds are closed in layers, beginning with the aponeurosis, finishing the operation with an intradermal suture.EFFECT: method provides a reduction in the risk of postoperative complications and faster healing of postoperative wounds due to the implementation of preoperative multiplanar vertebra reconstruction and transpedicular fixation of the lower cervical spine.1 cl, 10 dwg, 2 ex

Description

FIELD OF THE INVENTION

The invention relates to medicine, namely, neurosurgery and can be used when fixing the lower cervical spine from the dorsal access.

State of the art

A method is known from the prior art for performing transpedicular fixation from the posterior median access with screw insertion through contra-holes (Kim M.K., Cho SM, You SH, Kim IB, Kwak DS Hybrid Technique for Cervical Pedicle Screw Placement: Combination of Miniopen Surgery and Use of a Percutaneous Cannula System-Pilot Study. Spine. - 2015. - Vol. 4 0. - P. 1181-1186). According to this method, a skin incision is made along the posterior midline of the neck in the projection of the vertebrae into which the screws must be installed. Then skeletonization of the spinous processes, arches and lateral masses of the required vertebrae is performed. After the screw insertion point is open, a needle is installed through an additional incision away from the surgical wound to the screw insertion point, through which the port is installed using a system of dilators. Then through this port, using a special spatula, palpate the medial wall of the leg. After localization of the medial wall of the leg, the bone canal is drilled and the screw is installed transpedicularly. In the screw heads, rods are placed 1 on each side of the spinous processes, which are fixed with nuts.

The main disadvantage of this method is its invasiveness, since this method uses the posterior median access with skeletonization of all posterior structures of the required vertebrae. In addition to a large skin incision and several small ones (corresponding to the number of screws), with such accesses during skeletonization of the posterior vertebral structures, a severe injury is caused to the muscular apparatus of the cervical spine, which causes pain in the postoperative period in such patients, and mobility is limited due to the muscular-tonic syndrome . A cavity is also created in the paravertebral space, which contributes to the formation of paraspinal hematomas in the access area. Moreover, the authors used a method of palpation of the medial wall of the leg to increase the accuracy of screw installation, which makes it impossible to perform transpedicular fixation by this method in patients with a small thickness of the legs (3 mm or less) or its ossification.

Closest to the claimed is a method for performing transpedicular fixation from posterolateral mini-accesses (Schaefer C, Begemann P, Fuhrhop I, Schroeder M, Viezens L, Wiesner L, Hansen-Algenstaedt N. Percutaneous instrumentation of the cervical and cervico-thoracic spine using pedicle preliminary clinical results and analysis of accuracy // Eur Spine J. - 2011. - Vol.20. - P. 977-985). According to this method, a trocar is mounted under x-ray control in the anteroposterior projection to the site of insertion of the screw (somewhat lateral to the midline of the lateral mass of the vertebra). Access is performed by dissecting the skin, subcutaneous fat and aponeurosis. Subponeurotic muscle bundles are bred to the sides. The travel for the screw into the vertebral body is transpedicularly created using a drill at low speeds and a drill with a thickness of 3.5-4.0 mm. The progress of the drill is controlled under x-ray control in direct, lateral and oblique stackings. After the channel is drilled, the screw is installed. When all the screws are installed, through the already completed mini-accesses, 1 rod is inserted on each side and they are fixed in the screws with the help of nuts.

The main disadvantage of this method is the medial location of accesses. In most patients, the angle of the vertebral leg to the midline can be more than 40 °, so if you use the paramedian approaches proposed by the authors, then in case of stabilization of C5, C6 and C7 vertebrae, muscle bundles will prevent the implants from being installed at the right angle. To create a stroke for the screw through the leg into the vertebral body, the authors use a drill and a drill 3.5–4.0 mm thick, which they hold in their hands (“free hand”). In this regard, any artifact movement in the hands leads to a displacement of the installation path of the screw. The thinnest legs are anatomically located in the C3, C4 and C5 vertebrae. Given the above drawbacks, an incorrect trajectory in these vertebrae with perforation of the leg towards the spinal canal or vertebral artery was in 50% of the implants installed (11 screws out of 22). Also, this technique is not applicable for transpedicular fixation of adjacent segments. Too close localization of the screw insertion points on adjacent vertebrae will complicate the installation of the corresponding trocars, and therefore, the authors performed the described method of transpedicular fixation through at least 1 vertebra.

Disclosure of invention

The objective of the invention is to create a minimally invasive method for performing transpedicular fixation of the lower cervical spine, in accordance with which intermuscular access is made to the point of screw insertion along a pre-planned trajectory, and the installation of implants using a cannulated instrument along the spoke.

The technical result to which the invention is directed is the ability to perform transpedicular fixation of the lower cervical spine with the smallest deviation from a given trajectory of the screws, minimal injury to the muscular apparatus of the cervical spine and the least cosmetic defect, resulting in a reduction in the risk of postoperative complications, faster healing of postoperative wounds .

The problem is solved in that the method of transpedicular fixation of the lower cervical spine includes:

- preoperative multiplanar reconstruction of the vertebra in the axial plane based on computed tomogram data, according to which, according to the transpedicular trajectory, the following parameters are determined: screw length (a), its thickness corresponding to the thickness of the vertebral leg (b), screw installation angle with respect to the midline connecting the middle the vertebral body and the spinous process (c), the distance of the indent in the lateral direction from the midline to perform a skin incision (d) and the angle of installation of the C-arc of the x-ray apparatus relative to edney line to visualize the legs (e)

- after which skin access marking is performed on the patient’s body, for which the distance from the midline corresponding to the spinous processes of the vertebrae is retreated in the lateral direction by the amount (d), then radiography in the anteroposterior projection is performed to determine the cranial and caudal border of the skin incision,

- further, in accordance with the markup performed, a skin incision is made, after which subcutaneous fat and aponeurosis are dissected, bundles of muscle fibers are pushed to the sides up to the lateral sections of the lateral masses of the vertebrae,

- then, to the point of introduction of the screws, a port with a guide for knitting needles is installed, which is placed under x-ray control according to the screw installation path at an angle (s), after which the port is rigidly fixed and under x-ray control with the positioning of the arc of the x-ray machine at angles (s) and (e ) a Kirschner needle is inserted transpedicularly into the vertebral body, according to which, after preliminary drilling of the bone canal, a cannulated screw is installed with the parameters determined at the preoperative stage (a) and (b) wherein the visualization of the intervention zone is carried out using an operating microscope, for which a small dilator of the retractor is brought into the screw installation zone at right angles to its line through previously made skin incision and expansion of the muscle channel,

after which the wounds are sutured in layers starting from the aponeurosis, ending the operation with an intradermal suture.

In the claimed method, the localization of the skin incision is determined in advance according to CT data, respectively, the angle of the vertebral leg. This allows you to position the tool at an optimal angle to the vertebra. Access is performed by intermuscular dilution of muscle fibers, which, in contrast to the posterior median access, minimally injures the muscular apparatus of the cervical spine and does not create a paravertebral cavity. Smaller skin incisions (2 to 4-5 cm per adjacent segments instead of 1 incision over 12 cm) result in a better cosmetic result. After making access to the lateral masses of the vertebrae to the point of insertion of the screws, a port with a guide for the spokes is installed. It is placed under x-ray control according to the installation path of the screw and after that it is rigidly fixed using the universal endoscope holder. Unlike the “free hand” technique, this completely eliminates the displacement of ports from a given trajectory in the initial stages of fixation. The use of Kirschner spokes with a diameter of less than 1.5 mm allows you to safely install screws through the legs, the thickness of which is less than the thickness of the drill (less than 3.5 mm). The use of a cannulated instrument and the installation of clamps on the spokes exclude the deviation of the implants from a given trajectory.

The application of the proposed method allows you to activate patients in the early stages after surgery, to reduce the risks of postoperative complications and to reduce the overall period of disability of patients.

Brief Description of the Drawings

The invention is illustrated by drawings, where in FIG. 1 shows a photograph of the planning stage of an operation using multi-planar reconstruction of the vertebra in the axial plane; in FIG. 2 - intraoperative photograph, localization of skin incisions according to S. Schaefer et al. (1) and in accordance with the new technique (2); in FIG. 3 - stage of access, intraoperative photography, in accordance with which the muscle fibers are spread apart, the lateral part of the lateral mass of the vertebra is skeletonized; in FIG. 4 is an intraoperative photograph showing the positioning of the guide for Kirchner spokes in the surgical wound; in FIG. 5 is an intraoperative x-ray of the installation stage of the Kirschner needle, where the C-arc is oriented at an angle "c"; in FIG. 6 is an intraoperative x-ray of the installation stage of the Kirchner needle, where the C-arc is oriented at an angle "e"; in FIG. 7 is an intraoperative x-ray of the bone channel reaming stage, where the C-arch is oriented at an angle “e”, in FIG. 8 is an intraoperative x-ray of the installation stage of the cannulated screw, where the C-arc is oriented at an angle "e"; in FIG. 9 - postoperative CT in axial reconstruction, C5 vertebra, example 1; in FIG. 10-postoperative CT in axial reconstruction, C6 vertebra, example 1.

The positions in the figures indicate: a - the length of the screw, b - the thickness of the leg of the vertebra, corresponding to the thickness of the screw, c - the angle of the legs in relation to the midline, d - the size of the indent from the midline to perform a skin incision, e - the orientation angle of the C-arch X-ray relative to the midline to visualize the legs of the vertebra. 1 - localization of the section using the method of S. Schaefer et al .; 2 - localization of the incision according to the proposed method; 3 - lateral sections of the lateral mass of the cervical vertebra; 4 - a guide for Kirchner knitting needles; 5 - endoscope holder; 6 - Kirschner spoke; 7 - cannulated drill; 8 - cannulated screw.

The implementation of the invention

The first step is to plan the localization of the skin incision and determine the individual characteristics of the vertebra. To do this, based on the data of a computer tomogram, a multiplanar reconstruction of the vertebra in the axial plane is constructed according to the standard method. After that, they plan the optimal trajectory of the screw, its length (a), the thickness of the legs (b) and the angle of its location with respect to the midline (c), as well as the size of the indent from the midline for making a skin incision (d) and the installation angle C- arc of the x-ray apparatus for visualizing the legs (e) (Fig. 1).

The operation is performed in the position of the patient on the stomach. The head is rigidly fixed in Mayfield bracket.

The first step is marking the skin access. From the midline corresponding to the spinous processes of the vertebrae, they retreat by the amount (d), which was determined at the stage of preoperative planning (Fig. 1). Then, X-ray is performed in the anteroposterior projection to determine the cranial and caudal borders of the skin incision. It should be noted that the skin incision corresponding to the trajectory of the screw was always located 3-5 cm lateral from the localization described in the methodology of S. Schaefer et al. (Fig. 2). The skin, subcutaneous fat and aponeurosis are dissected with a scalpel. Subsequent bundles of muscle fibers are pushed to the sides up to the lateral sections of the lateral masses of the vertebrae (Fig. 3). Next to the lateral mass, under radiological control, a port with a guide for the knitting needles is positioned and the screw installation paths are positioned accordingly. Take pictures along the legs (angle "c", Fig. 1) and perpendicular to it (angle "e", Fig. 1). Next, the port is rigidly fixed using a standard holder for the endoscope (Fig. 4). Under X-ray control using oblique projections (the location of the C-arc at angles “c” and “e”), the Kirschner spoke is installed transpedicularly into the vertebral body (Figs. 5 and 6). On the spoke, after preliminary reaming of the bone canal (Fig. 7), a cannulated screw is installed (Fig. 8). Next, the installation of the transpedicular system using rods is performed according to the generally accepted methodology.

In this method, transpedicular fixation was performed in four patients.

Example 1. Patient M., 36 years old, was admitted to the research institute of the joint venture after an accident (driver). Immediately after the injury, I felt pain in my neck and weakness in my arms and legs. Neurological status showed paresis, pain and tactile sensitivity disorders at C5 level (grade D according to the ASIA scale). CT scan of the cervical spine revealed bilateral C5 vertebral fracture with complete rupture of the disco-ligament complex. The patient underwent a simultaneous two-stage operation. The first stage was performed classical discectomy of the C5-C6 vertebrae, reduction of the dislocation of the vertebra, installation of the interbody cage according to the generally accepted technique. Then the patient was turned on his stomach. The second stage was performed transpedicular fixation of C5-C6 vertebrae by the present method. Control CT images are shown in FIG. 9 and 10. In both vertebrae, the screws are installed correctly. In the postoperative period, pain and muscle-tonic syndrome in the patient were not expressed and completely regressed on the 3rd day. The patient was activated 24 hours after surgery. Given the rigidity of fixation, postoperative immobilization of the cervical spine by a rigid head holder was not required. The size of the scars was 5 cm. The patient was discharged in satisfactory condition. When assessing the immediate and long-term results of treatment, an excellent orthopedic result was found.

Example 2. Patient S., 72 years old, was admitted with complaints of pain in the neck and weakness in the legs after falling from the stairs. The examination revealed a complicated fracture of the C7 vertebra, fracture of the arch of the C7 vertebra, concrescence of C5-C6-C7 vertebrae, spinal cord injury, ASIA C. The patient underwent a simultaneous two-stage operation. The first stage was performed classical discectomy of the C7-Th1 vertebrae, reduction of the dislocation of the C7 vertebra, installation of the interbody cage according to the generally accepted technique. Then the patient was turned on his stomach. The second stage was performed transpedicular fixation of C5-C6-C7-Th1-Th2-Th3 vertebrae. The screws installed by the claimed method. Performing the operation according to the described technique made it possible to achieve the necessary trajectory for installing screws with minimal injury to the muscular apparatus of the neck. The patient was discharged after 2 weeks for further rehabilitation.

Claims (6)

A method for performing transpedicular fixation of the lower cervical spine, comprising - preoperative multiplanar reconstruction of the vertebra in the axial plane based on computed tomogram data, according to which, according to the transpedicular trajectory, the following parameters are determined: screw length (a), its thickness corresponding to the thickness of the vertebral leg (b), screw installation angle with respect to the midline connecting the middle the vertebral body and the spinous process (c), the distance of the indent in the lateral direction from the midline to perform a skin incision (d) and the angle of installation of the C-arc of the x-ray apparatus relative to edney line to visualize the legs (e) - after which skin access marking is performed on the patient’s body, for which the distance from the midline corresponding to the spinous processes of the vertebrae is retreated in the lateral direction by the amount (d), then radiography in the anteroposterior projection is performed to determine the cranial and caudal border of the skin incision, - further, in accordance with the markup performed, a skin incision is made, after which subcutaneous fat and aponeurosis are dissected, bundles of muscle fibers are pushed to the sides up to the lateral sections of the lateral masses of the vertebrae, - then, to the point of introduction of the screws, a port with a guide for knitting needles is installed, which is placed under x-ray control according to the screw installation path at an angle (s), after which the port is rigidly fixed and under x-ray control with the positioning of the arc of the x-ray machine at angles (s) and (e ) a Kirschner needle is inserted transpedicularly into the vertebral body, according to which, after preliminary drilling of the bone canal, a cannulated screw is installed with the parameters determined at the preoperative stage (a) and (b) wherein the visualization of the intervention zone is carried out using an operating microscope, for which a small dilator of the retractor is brought into the screw installation zone at right angles to its line through previously made skin incision and expansion of the muscle channel, after which the wounds are sutured in layers, starting with an aponeurosis, ending with an intradermal suture.

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