RU2729182C1 - Hybrid endofixator with an adjustable interbody element (versions) and a device for its adjustment and installation - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: group of inventions relates to medical equipment, specifically to neurosurgery, in particular to an implanted hybrid endofixator with an adjustable interbody element and a device for its adjustment and installation, and can be used in treating cervical spine diseases and injuries. Hybrid endofixator with adjustable interbody element includes a bent plate with holes for screws, contains two side shafts located on the plate and a screw of the stop plate. On each side shaft with proximal to the plate side is movable relative to the shaft is a front roller, and from the distal rear roller, besides, the locking plate screw is screwed into the stop plate, where the rear rollers rest against, and on the side shafts there are splines intended for adjustment of the rollers. In compliance with second version, hybrid endofixator with adjustable interbody element comprises bent plate with holes for screws, comprises a head on the plate, crowned with connected to two front rollers on their sides and a hollow shaft connected by crown connection to the front roller, having internal thread, through the heads and the shaft locking screws screwed into threaded channels of the rolls are passed, Besides, on heads and heads of lock screws there are splines for adjustment of rollers. In the third version, the hybrid endofixator with an adjustable interbody element includes a bent plate with holes for screws, contains two side shafts located on the plate and a screw of the stop plate. On each side shaft with distal side relative to the plate there is a rear roller, and on the screw of the stop plate proximal to the plate there is an unpaired ventral roller, besides, a locking plate is fixed on the screw of the retaining plate, in which the rear rollers rest, and on the heads of the ventral roller, shafts of the dorsal rolls and the screw of the stop plate, there are splines for adjusting the rollers. Device for adjustment and installation of the above endofixator includes a plate and a hollow rod installed inside the plate, as well as two pair of side switches. Each pair of side switches is located on side of plate at some distance on different sides of rod, besides, on side of docking with endofixator, pairs of side keys are close to rod. Inside the hollow rod there are also two keys, on the side of docking with the endofixator, the ends of the keys are made so that they fit tightly with splines on the endofixator rollers, besides, on the side of docking with the endofixator there are collets connected to the bushing through rod bars, and also between the bushing and the plate there is a spring on the rod.

EFFECT: use of inventions makes it possible to change the height of an interbody element in its different parts to achieve optimal dimensions for more stable fixation and correction of spinal deformations.

11 cl, 12 dwg

Description

The invention relates to medicine, namely to neurosurgery, in particular to an implantable hybrid endofixator with an adjustable interbody element and a device for adjusting and installing it and can be used in the treatment of diseases and injuries of the cervical spine.

There is a known device (Endofixator plate for the cervical spine: patent No. 2299045, Russian Federation, application No. RU 2005121108; claimed 05.07.2005; publ. 20.05.2007), containing a hollow body and wing-shaped ebbs with holes. The body is made along the front surface with a technological hole for installing bone-grafting material, and on the ends - with teeth to prevent displacement. The technological hole for the installation of bone grafting material has a height corresponding to the height of the interbody defect. The holes in the wing-shaped ebbs are made in three, one of which is threaded for the locking screw, and two holes are made with internal convergence for inserting screws into them. There are oval transitions between the body and the pterygoid ebbs to enter the formed grooves in the vertebral bodies.

The disadvantage of this technical solution is the relatively low reliability of fixation, due to the impossibility of complete and even fit of the hollow body to the mating surfaces of the vertebral bodies due to the impossibility of adjusting the interbody element in height.

Known device (Intersomatic installation and fusion system: patent 6235059, United States of America, application No. US 19980147083; filed 02.12.1998; publ. 22.05.2001), including one or more open bodies for placing bones in them for insertion between two vertebrae during discectomy. In this case, the body has an outer plate-like element (on its rear surface, extending on both sides of the body) in a plane perpendicular to the plane of insertion of the body, and provided at each of its ends with means for fixing the plate on at least two adjacent vertebrae, which must be attached to each other with a cage. The device can be divided into two parts: a cage and a plate.

The disadvantage of such a device is the relatively low reliability of fixation due to the impossibility of complete and uniform adhesion of the hollow body to the mating surfaces of the vertebral bodies due to the impossibility of adjusting the interbody element in height. Also the disadvantage of this device is the limited use in case of injury due to the version with only two-screw fixation.

Known device (PEEK PREVAIL Cervical Interbody Device [Electronic resource]: Spine image library by business unit // Medtronic website. URL: https://www.medtronic.com/us-en/about/news/media-resources/image -library / business-unit / spine.html - date of access: 05/20/2019), consisting of an I-beam implant placed in the interbody space with fixation with two screws through the adjacent corners of the mating vertebral bodies.

The disadvantage of this technical solution is the relatively low reliability of fixation, due to the impossibility of complete and uniform adhesion of the hollow body to the mating surfaces of the vertebral bodies, the absence of an extra-bone fixing element in the form of a plate in the design, the impossibility of choosing the direction of the fixing screw.

A device is known (Intervertebral insert and plate assembled with it: patent No. 2506930, Russian Federation, application No. RU 2011122797; Appl. 06.11.2009; publ. 20.02.2014), containing the first and second elements of fixation of bones, insert, interlocked with insert the plate and the first and second spring-loaded latches preventing the backward extension of the first and second bone fixation elements.

Among the disadvantages are the relatively low reliability of fixation due to the low congruence of the insertion and mating surfaces of the vertebral bodies, the small length of the plate, limiting the possibilities of using it for deformity correction and in case of vertebral dislocations, and the possibility of a screw only in one direction.

Known device (SCARLET®AC-T fixed neck cage [Electronic resource]: Interbody cages // Spineart website. URL: http://spineart.ru/product-platforms/5/10 - date of access: 05/20/2019), which is an implant with a window for a bone graft with screws, held in the adjacent corners of the mating vertebrae.

The disadvantage of this device is the relatively low reliability of fixation, low congruence of the implant and mating surfaces, the absence of a fixing element in the form of a plate, limited use for deformity correction and in case of injury of the cervical spine.

Known device (TRYPTIK MC cervical modular cage [Electronic resource]: Interbody cages // Spineart website. URL: http://spineart.ru/product-platforms/5/13 - date of access: 05/20/2019), containing an implant with serrated edges and a window for a bone insert, as well as a plate movable at the attachment point with the possibility of its removal.

The disadvantage of such a device is the relatively low reliability of fixation due to the impossibility of complete and uniform adhesion of the hollow body to the mating surfaces of the vertebral bodies due to the impossibility of adjusting the interbody element in height. Also, the disadvantage of this device is its limited usability due to the version with a two-screw fixation.

Also known is the device (ZERO-P® Spacer [Electronic resource]: Products // Website of the DePuySynthes company. URL: https://www.depuysynthes.com/hcp/spine/products/qs/Zero-P-Spacer - access date: 05/20/2019), consisting of a circular implant placed in the interbody space with fixation with 4 screws, which are passed through the adjacent corners of the mating vertebral bodies.

Known device (RSV 2-IN-1 CERVICALPLATE-CAGE [Electronic resource]: Nilai Medical Center. URL: http://www.nilaimc.com/downloads/Scientx_PCB_2in1_Cervical_Plate_Cage.pdf - date of access: 05/20/2019), and also known device (RSV - Evolution [Electronic resource]: Products // Alphatec Spine. URL: http://www.alphatecspine.ru/index.php?option=com_content&view=article&id=59&Itemid=65 - date of access: 20.05.2019), consisting of a titanium cage and a PEEK plate.

The disadvantage of these devices is the relatively low reliability of fixation, as well as limited applicability for cervical trauma and for deformity correction.

Known device (Vertebral separation device with modular attachment: patent No. 2344792, Russian Federation, application No. RU 2004104341; claimed 12.07.2002; publ. 27.01.2009), having the size and shape for insertion into the intervertebral cleft separating the opposite surfaces of two adjacent vertebrae, and additionally contains at least one intervertebral separator, made in the form of a ring, having a bar with a height along the spine axis that is less than the rest of the separator. The bar of the intervertebral separator contains at least one hole in the bar for inserting a protruding part of the fastening structure for attaching the intervertebral separator to at least one of the vertebrae.

The disadvantage of such a device is the relatively low reliability of fixation, due to the impossibility of complete and uniform adhesion of the hollow body to the mating surfaces of the vertebral bodies due to the impossibility of adjusting the interbody element in height, limited applicability in trauma of the cervical spine due to the presence of a variant with only two-screw fixation.

The closest to the claimed device is a device (Device for supporting cervical vertebrae: patent No. 6231610, United States of America, application No. US 19990382808; filed 25.08.1999, published 15.05.2001), which is a regular hollow prism with a base in the shape of an isosceles trapezoid with two supporting surfaces, each of which has teeth and a cervical plate (curved) with two holes for screws. This device is taken as a prototype.

The disadvantage of the prototype is the relatively low reliability of fixation due to the incomplete congruence of the hollow body and the mating surfaces of the vertebral bodies due to the impossibility of adjusting the interbody element in height, limited use for cervical trauma and to correct deformities.

The technical problem lies in the need to develop a device with a high reliability of fixation, increased congruence of the interbody element and mating surfaces of the vertebral bodies, and the possibility of correcting deformities of the cervical spine.

The technical result consists in expanding the possibilities of regulating the interbody element of the endofixer.

The technical result is achieved in that a hybrid endofixer with an adjustable interbody element, including a bent plate with holes for screws, according to the invention contains two side shafts and a lock plate screw located on the plate, while on each side shaft from the side proximal to the plate it is movable relative to The front roller is located on the shaft, and the rear roller is located with the distal one, in addition, the lock plate screw is screwed into the lock plate against which the rear rollers abut, and on the side shafts there are slots for adjusting the rollers.

The technical result is also achieved in that a hybrid endofixer with an adjustable interbody element, including a curved plate with holes for screws, according to the invention contains heads located on the plate, with a crown connection connected to two front rollers on the sides and a hollow shaft connected by a crown connection with the front roller, having an internal thread, through the heads and the shaft are passed locking screws screwed into the threaded channels of the rollers, in addition, there are slots on the heads and heads of the locking screws for adjusting the rollers.

The technical result is also achieved in that a hybrid endofixer with an adjustable interbody element, including a bent plate with holes for screws, according to the invention contains two side shafts and a lock plate screw located on the plate, while on each side shaft from the distal side relative to the plate is located the rear roller, and an unpaired ventral roller is located on the screw of the locking plate proximal to the plate, in addition, a locking plate is fixed on the screw of the locking plate, against which the rear rollers abut, and on the heads of the ventral roller, shafts of the dorsal rollers and the screw of the locking plate are slots to adjust the rollers.

The technical result is also achieved by the fact that a device for adjusting and installing an endofixer according to any of the above options, which includes a plate and a hollow rod installed inside the plate, as well as two pair of side keys, with each pair of side keys located on the side of the plate at a certain distance on opposite sides of the rod, in addition, on the side of the endofixator, the pairs of side keys are close to the rod, while there are also two keys inside the hollow rod, on the side of the endofixer, the ends of the keys are made in such a way that they fit tightly with the slots on the rollers of the endofixator, in addition, on the side of the docking with the endofixer, there are collets connected to the sleeve through rod rods, and a spring is also located between the sleeve and the plate on the rod.

The above design options for the endofixator provide the ability to change the height of the interbody element in its various parts to achieve optimal dimensions for more stable fixation and correction of spinal deformities. The above design of the device for adjustment and installation ensures that the rollers (having an elliptical shape when viewed in cross-section) are brought to a position in which there is the most complete contact with the mating surfaces of the vertebrae with the possibility of their removal or convergence and this position is fixed with a stopper. Thus, when using the claimed design options for the endofixer, an expansion of the possibilities of adjusting the interbody element is achieved, due to the provision of the possibility of adjusting it in height at four and / or three points.

The first version (shown in Figs. 1-4) of a hybrid endofixer with an adjustable interbody element (with four rollers) includes a plate 1, two side shafts 2 located on it, and a lock plate screw 3 (smooth throughout, and at the end on the side of the lock plate contains threads). A stopper plate 4 is attached to the screw of the locking plate 3 (locking screw) 4. On each side shaft 2, from the side proximal to the plate 1, the front (ventral) roller 5 is movably located, and from the distal side relative to the plate 1 on each side shaft 2, the rear ( dorsal) roller 6. Each posterior (dorsal) roller 6 with the distal side relative to the plate 1 abuts against the locking plate 4. Around the corners of the plate 1 holes 7 are made for screws, as well as grooves 8 for collet clamps are made on two opposite edges of the plate 1. The front (ventral) rollers 5 and the rear (dorsal) rollers 6 are made in the form of elliptical cylinders or truncated elliptical cones, corrugation is made on their outer surfaces, and along the axis of the rollers 5 there is a channel for tightly passing the side shafts 2 and the screw of the locking plate, respectively. In the four-roller design, the screw of the lock plate 3 goes between the pairs of rollers separately. The heads of the shafts and ventral ridges are located concentrically relative to each other. Slots 9 are made on the end parts of the shafts 2, the heads of the front rollers 5 and the screw of the locking plate 3. The plate 1 is made curved (the edges are directed towards the side shafts 2). In various versions of the endo-fixator, the plate 1 can be made quadrangular (with four holes 7 for screws) or z-shaped (with two holes 7 for screws). Thus, on the plate on the side of each ridge there are two slots 9 (for the dorsal and for the ventral ridge). There are 5 slots in total: the lock plate screw and on the sides of it - the ventral roller and shaft.

The second version (shown in Figs. 5, 6 and 7) of a hybrid endofixer with an adjustable interbody element (with an unpaired dorsal roller) includes a plate 1 and heads 10 located movably on it, connected by a crown connection 11 to the hollow shaft 12 of the dorsal roller 6. On the shaft 12 at a distance of 5-7 mm (at a distance of the length of the ventral ridges) from the plate 1, the posterior (dorsal) ridge 6 is installed by means of a crown connection. A locking screw 3 is passed through the smooth channel of the shaft 12 and the head and is screwed into the threaded channel of the dorsal roller. Also on the plate 1, two front (ventral) rollers 5 are movably located, connected to the plate by hollow heads by means of a crown connection. A locking screw 3 is passed through the heads, also screwed into the threaded channel of the ventral roller. Around the corners of the plate 1, holes 7 are made for screws, and grooves 8 for collet clamps are made on two opposite edges of the plate 1. The anterior (ventral) rollers 5 and the posterior (dorsal) roller 6 are made in the form of elliptical cylinders or truncated elliptical cones, their outer surfaces are corrugated. On the heads of the front rollers 5 and the shaft of the dorsal roller 6, slots 9 are made. The plate 1 is made curved (the edges are directed towards the side shafts 2). In various versions of the endo-fixator, the plate 1 can be made quadrangular (with four holes 7 for screws) or z-shaped (with two holes 7 for screws). Also, in the second version, additional slots 9 are made for locking screws (not shown in the drawing) threaded through the shaft 2 and the anterior ventral rollers 5.

The third version (shown in Fig. 8) of a hybrid endofixator with an adjustable interbody element (with an unpaired ventral roller) includes plate 1, as well as two side shafts 2 located on it and a lock plate screw 3. The ventral roller is located in the middle of the plate 3 (in geometric center) and has a smooth channel through which the screw of the locking plate 3 is passed. Dorsal rollers 6 are located on each side shaft distal from the plate. The rollers 6 are made in the form of an elliptical cylinder or a truncated elliptical cone. On the threaded end of the locking screw with an emphasis on the distal bases of the dorsal rollers, there is a locking plate 3. Near the corners of the plate 1, holes 7 for screws are made, and grooves 8 for collet clamps are made on two opposite edges of the plate 1. On the end parts of the shafts 2, the head of the front roller 6 and the screw of the locking plate 3, there are slots 9. The plate 1 is made curved (the edges are directed towards the side shafts 2). In various versions of the endo-fixator, the plate 1 can be made quadrangular (with four holes 7 for screws) or z-shaped (with two holes 7 for screws).

The device for adjusting and installing the endofixator (shown in Fig. 9, 10, 11 and 12) includes a plate 13 and a hollow rod 14 installed inside the plate (perpendicular to it), as well as two pairs of side keys 15 located concentrically (one in the other ), while each pair of side keys 15 is located on the side of the plate 13 at a certain distance on different sides of the rod 14. At the same time, on the side of the docking with the endofixer, pairs of side keys 15 are close to the rod 14. In this case, two keys 16 are also located inside the hollow rod. The tips of the keys 15, 16 are made in such a way that they are tightly joined by the slots on the rollers 5 and shafts 2, which adjust the rollers 6 and tighten the locking screws 3 (screws of the locking plate). Each wrench is equipped with a handle 17. In addition, on the side of the docking with the endofixer there are collets 18 connected to the bushing 19 through rod rods 20. Also, a spring 21 is located between the bushing 19 and the plate 13 on the rod 14. A scale is radially applied to the plate 13 around each wrench 22.

The end fixator elements are made of titanium or titanium and polyetherketone, and the tool for setting and installation is made of medical steel. In addition, corrugation is made on the end surfaces of the rollers, the surfaces of the plate 1 and the stop plate 3 in contact with the rollers.

The claimed device operates as follows.

According to MRI or X-ray CT, the state of the bone structure, the relief of the endplates, and the presence of kyphotic deformity are assessed.

The required endofixator option is selected based on the presence of kyphotic deformities and the condition of the endplates (traumatic changes, changes in the relief of the endplates in spondylopathies, Schmorl's hernias, etc.). In case of intact endplates without kyphotic deformation, preference is given to a four-roller design (Figs. 1, 2 and 3). In order to correct the kyphotic deformity - four-roller (with a lesser degree of severity) or three-roller with an unpaired anterior roller (Fig. 8), since this design allows it to be performed with a large base diameter, which means that the interbody distance in the anterior parts of the spinal motion segment is increased by large value. An endofixer with an unpaired posterior ridge (Figs. 5, 6, 7) is used for destruction of the postero-lateral sections of the endplates of the mating vertebrae, as well as when it is necessary to increase the height of the interbody space in the posterior sections.

At the stage of preoperative planning, the height of the interbody element is calculated at the given points. For this, an equation is used that describes the dependence of the height on the angle of installation of the endofixator rollers. At the same time, different equations are used for different sizes of rollers:

for roller 3 × 5 mm:

y = 21.41x ³ -266.17x ² + 1122.2x-1543.8, where:

x is the simulated height;

y - roller installation angle;

for roller 4 × 6 mm:

y = 21.223x ³ -326.04x ² + 1689.8x-2896.7, where:

for roller 5 × 7 mm:

y = 21.151x ³ -386.91x ² + 2379.8x-4865.9, where:

for roller 3 × 5 mm:

y = 21.41x ³ -266.17x ² + 1122.2x-1543.8;

for roller 4 × 6 mm:

y = 21.223x ³ -326.04x ² + 1689.8x-2896.7;

for roller 5 × 7 mm:

y = 21.151x ³ -386.91x ² + 2379.8x-4865.9.

Also, a computer program can be used for the calculation.

After the calculation, they proceed to the stage of the operation, which slightly differs for different versions of the endofixator. After access to the anterior surfaces of the vertebral bodies and discectomy with the required volume of decompression, the spinal motion segment is stabilized. To do this, the keys 15, 16 of the device for adjusting and installing the endofixator are installed in such a way that the tips of the keys fit snugly in the slots of the side shafts 2 of the endofixator, as well as the locking screw 3. The surgeon clamps the sleeve 19 with his fingers and pulls it up, which causes the collets 18 devices are opened by rod rods 20, when the sleeve 19 is returned downward, the collet 18 is closed. At the same time, the endofixator is gripped so that the collets 18 are in the grooves 8 of the endofixator. Then the device is transferred to a horizontal position (relative to the longitudinal axis of the rollers). The endoprosthesis is placed in the gap in the place of the removed disc, while the plate 1 of the endofixer fits tightly on the front surfaces of the vertebral bodies, by turning the handles 17 of keys 15, 16, the rollers 5, 6 are rotated to change the height of the interbody element, the angle of rotation is controlled using scales 22. Next, the rollers are locked by tightening the screw 3 of the locking plate 4 using one of the keys 16 of the hollow rod 9 (for the second version of the endofixer with an unpaired dorsal roller, the locking screws 3 are also tightened with keys 15). In this case, the locking plate 4 presses the rollers 5, 6 against each other and the main plate 1 of the endofixator. In the absence of a locking plate 4 (in the variant with an unpaired dorsal roller), the rollers 5, 6 are pressed against the main plate 1 by tightening the locking screws 3. After that, the endofixator is fixed to the vertebral bodies with screws through holes 7 in the endofixator plate 1. Collets 18 are loosened by lifting the sleeve 19, the tool for installation and adjustment is removed. After that, the reliability of fixation is checked, X-ray control is performed and the wound is sutured.

It is also possible to select the installation of endofixers intraoperatively using the C-arm in the scopy mode.

The claimed invention is illustrated by examples.

Example 1.

Patient S., 36 years old, was admitted to the neurosurgical department 3 hours after being injured as a result of diving. In the neurological status, C4 root compression syndrome on the right. X-ray imaging of the cervical spine revealed a flexion type of injury to the cervical spine in the form of left-sided dislocation of the C3 vertebra with the formation of an unstable spinal motion segment. According to clinical data and examinations, the diagnosis was formulated: "Closed complicated anterior left-sided dislocation of the C3 vertebra".

On the same day, the patient underwent C3-C4 discectomy, open reduction of dislocation, fusion with a hybrid endofixator with an adjustable interbody element to stabilize the spinal motion segment of the cervical spine. For stabilization, a four-roll endofixator with a quadrangular plate was selected as it meets the requirements of more reliable stabilization and provides the best adhesion in the endplate-endofixator system due to the greatest congruence to prevent recurrence of dislocation. The size of the rollers for the selected endofixator was 4 × 6 mm for the front and 5 × 3 mm for the rear. The calculated height according to the RKT should be 4.7 mm in the anterior sections and 4.2 mm in the rear. Installation angle of front rollers 47 °, rear 60 °.

The postoperative period was unremarkable. Verticalization on the next day with cervical spine orthotics. Control CT scan of the cervical spine on the next day after the operation and X-ray on the 8th day - the dislocation was adjusted, the standing of the hybrid endofixator was satisfactory. Discharged from the hospital on the 12th day. When examined after 8 months, he does not present any complaints and works in the same place as a driver. Neurological examination revealed no deficiency. Karnofsky index 100 points.

Example 2.

Patient N., 57 years old, was admitted to the neurosurgical department with complaints of weakness in the extremities, deterioration of fine motor skills in the fingers of the right hand, limitation of movements in the cervical spine, forced position of the head and cervical spine.

In the neurological status: upper peripheral, lower central paraparesis with the formation of combined contracture in the left wrist joint

With RCT - kyphotic deformity of the cervical spine with the formation of bone block C4-C5, C5-C6.

spinal cord deformity on MRI. Myelopathic changes at the C4-C5 level,

Diagnosis: fixed kyphotic deformity of the cervical spine, degenerative stenosis of the cervical spine at the level of C4-C5, C5-C6, myelopathy of the cervical spine.

The patient underwent planned surgical treatment - discectomy C4-C5, C5-C6 with removal of the bone block, resection of the posterior osteophytes, deformity correction with stabilization with hybrid endofixers with an adjustable interbody element. For the C4-C5 level, an endofixator with an unpaired anterior roller was selected to correct a greater kyphotic deformity, for the C5-C6 level, a four-roller. Both endo fixators are in Z-plate design due to the need to be placed in adjacent segments

The size of the rollers for the selected endofixator for the C4-C5 level was 5 × 7 mm for the front and 5 × 3 mm for the rear. The estimated height of the RKT should be 7 mm in the anterior sections and 4.1 mm in the rear. Installation angle of the front roller 90 °, rear 59 °; for the C5-C6 level was 6 × 4 mm for the front and 5 × 3 mm for the rear. The estimated height of the RKT should be 5.9 mm in the anterior sections and 4.5 mm in the rear. The angle of installation of the front roller is 82 °, the rear roller is 67 °.

With RCT on the 3rd day after the operation, the kyphotic deformity was eliminated, the endofixator standing was satisfactory.

In the postoperative period, against the background of the therapy, the patient has an increase in strength in the lower extremities, deltoid and biceps muscles on both sides, in the triceps on the right.

The patient was discharged with continuing positive dynamics.

Example 3

Patient L., 32 years old, was admitted to the neurosurgical department 3 hours after falling into the inspection pit with complaints of weakness in the arms and legs.

According to the X-ray CT, dislocation of the C5 vertebra with fracture of the lower articular processes and the arch on the right with the transition to the body.

Diagnosis: "dislocation of the C5 vertebra with a fracture of the lower articular processes and the arch on the right with the transition to the body."

On the same day, open reduction of the dislocation, ventral cervicospondylodesis with a hybrid endofixator with an H-shaped plate and an unpaired dorsal ridge was performed. The choice of an endofixer is associated with the impossibility of using a four-roll interbody element due to the destruction of the end plate in the place of the intended location of the rear right roll with a four-roll version of the endofixer, and the H-shaped plate was preferred as providing the greatest fixation reliability.

The size of the rollers for the selected endofixator was 5 × 7 mm for the front and 6 × 4 mm for the rear. The calculated height according to RKT should be 6.3 mm in the anterior sections and 6.1 mm in the rear. The angle of inclination of the front rollers 59 °, back 96 °.

Already on the next day, there was a positive trend in the form of an increase in strength and range of motion in the arms and legs, a decrease in the level of sensitive disorders. RT-control on the next day and on radiographs after 2 weeks - the dislocation was adjusted, the endofixator was in satisfactory position. After 18 days he was discharged with a moderate neurological deficit.

Claims (11)

1. Hybrid endofixer with an adjustable interbody element, including a curved plate with holes for screws, characterized in that it contains two side shafts and a lock plate screw located on the plate, while on each side shaft from the side proximal to the plate it is movable relative to the shaft the front roller, and with the distal rear roller, in addition, the lock plate screw is screwed into the lock plate, against which the rear rollers abut, and on the side shafts there are slots for adjusting the rollers. 2. The hybrid endofixer according to claim 1, characterized in that the plate is quadrangular and includes four holes for screws. 3. Hybrid endofixer according to claim 1, characterized in that the plate is z-shaped and includes two holes for screws. 4. Hybrid endofixer with adjustable interbody element, including a curved plate with holes for screws, characterized in that it contains heads located on the plate, with a crown connection connected to two front rollers on the sides and a hollow shaft connected by a crown connection with a front roller, having an internal thread , through the heads and the shaft, the locking screws are passed, screwed into the threaded channels of the rollers, in addition, there are slots on the heads and heads of the locking screws for adjusting the rollers. 5. Hybrid endofixer according to claim 4, characterized in that the plate is made quadrangular and includes four holes for screws. 6. The hybrid endofixer according to claim 4, characterized in that the plate is z-shaped and includes two holes for screws. 7. Hybrid end fixator with an adjustable interbody element, including a bent plate with holes for screws, characterized in that it contains two side shafts and a lock plate screw located on the plate, while on each side shaft from the distal side to the plate there is a rear roller, and on the screw of the stop plate, proximal to the plate, there is an unpaired ventral roller, in addition, a stop plate is fixed on the screw of the stop plate, against which the rear rollers abut, and on the heads of the ventral roller, shafts of the dorsal rollers and the screw of the stop plate there are slots for adjusting the rollers ... 8. Hybrid endofixer according to claim. 7, characterized in that the plate is quadrangular and includes four holes for screws. 9. Hybrid endofixer according to claim 7, characterized in that the plate is z-shaped and includes two holes for screws. 10. Device for setting and installing the endofixator according to any one of paragraphs. 1, 4, or 7, which includes a plate and a hollow rod installed inside the plate, as well as two pair of side keys, with each pair of side keys located on the side of the plate at a certain distance on different sides of the rod, in addition, on the side of joining with with the endofixer, the pairs of side keys are close to the rod, while inside the hollow rod there are also two keys, on the side of the docking with the endofixer the ends of the keys are made in such a way that they fit tightly with the slots on the endofixator rollers, in addition, collets are placed on the side of the docking with the endofixer connected to the bushing through rod rods, and also between the bushing and the plate on the rod there is a spring. 11. A device according to claim 10, characterized in that a scale is radially applied to the plate around each key.

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