RU2460499C2 - Device for symmetric recovery of intervertebral space height and vertebra fixation - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine. Device contains hollow case in form of parallelepiped, with oval holes on its upper and lower walls. Anterior and posterior walls of device are provided with wedge-shaped spacers and threaded bar, which has groove for placement of wrench in its posterior part. In the centre of device there are two pins, holding construction together and guiding movement of upper wall. Case is made with possibility of vertical symmetric opening by movement of wedge-shaped spacers to the centre of device on threaded bar. Upper wall of hollow case is made curved. Threaded bar is made with right/left thread. Pins are made cylindrical. On upper surfaces of upper and lower walls of case bases of pyramid-shaped protrusions with 1-2 mm high pyramids are located evenly.

EFFECT: invention ensures carrying out uniform symmetric correction of intervertebral space height taking into account vertebra structure and recovery of bend of lumbar spine close to natural lordosis by installation of device on one side with prevention of its displacement.

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Description

The invention relates to medicine, in particular to traumatology and orthopedics, and can find application in practical healthcare.

A device for restoring and fixing the intervertebral gap in the form of a parallelepiped with the possibility of dosed correction of the height of the intervertebral gap (D. Attia: PLIF using the Varilift expandeble cages: an experience reaching 5 years about stand alone cages. Journal of Bone and Joint Surgery - British Volume, Vol. 84-B, Issue SUPP_III, 298. Copyright © 2002 by British Editorial Society of Bone and Joint Surgery).

The disadvantage of this device is the need to install it in the intervertebral space from two sides, which significantly increases the time and invasiveness of surgery.

Closest to the proposed device is a device made in a bean-like form of carbon fiber with oval windows on the upper and lower walls of the body through which the body is filled with bone chips. This device has a predetermined non-changing shape (Quigley KJ, Alander DH, Bledsoe JG .: An in vitro biomechanical investigation: variable positioning of leopard carbon fiber interbody cages. J Spinal Disord Tech. 2008, Aug; 21 (6): 442-7 )

To install this device, a tool is usually used consisting of a handle and a guide head with a thread at its end.

The disadvantage of this device is that it does not imply a dynamic restoration of the intervertebral space when it decreases, the lack of fixation of the vertebrae.

At the same time, there is also no possibility of a dosed opening of the device relative to the axis of symmetry, which is necessary for correction of the bend of the lumbar spine.

The technical result of the invention is to provide:

- conducting a uniform symmetric correction of the height of the intervertebral gap, taking into account the structure of the vertebra;

- restoration of the bend of the lumbar spine, close to natural lordosis by installing the device on one side while preventing its displacement.

The achievement of the technical result is ensured by the following set of essential features characterizing the invention:

A device for symmetrical restoration of the height of the intervertebral space and fixation of the vertebrae on one side contains a hollow body in the form of a parallelepiped, with oval windows on its upper and lower walls, the front and rear walls of the device having wedge-shaped spacers and a threaded rod having a recess for holding the key in the back its parts. In the center of the device from two sides there are two pins that hold the structure together and direct the movement of the upper wall. The housing is made with the possibility of vertical symmetric opening by moving the wedge-shaped spacers to the center of the device along the threaded rod.

A feature of the invention is as follows:

The upper wall of the hollow body is made curved to ensure adaptation to the structure of the vertebra.

The threaded rod is made with right / left thread for uniform simultaneous progressive movement of the upper wall.

The pins are made cylindrical to prevent jamming of the upper wall when moving it.

On the outer surfaces of the upper and lower walls of the casing, the bases of the pyramidal protrusions with a pyramid height of 1-2 mm are evenly located for firm fixation to the surfaces of the vertebrae.

Figure 1 is a side view of the device when folded;

Figure 2 is a top view of the device;

Figure 3 - view of the device in the extended state;

Figure 4 - a device for symmetric restoration of the height of the intervertebral gap and a tool for its installation.

Installation of a device for symmetrical restoration of the height of the intervertebral space and fixation of the vertebrae on the one hand is carried out using the proposed tool as follows.

Bone or biomaterial is introduced into the device made of titanium through oval windows on the upper and lower sides of the body into the body inside. The device is mounted on a tool for installation. Then, through a preformed window in the intervertebral space under X-ray monitoring, the device is introduced into the anterior intervertebral space. Upon completion of the installation of the device in the bed, clockwise rotational movements of the screwdriver are made with a T-handle and a flat section at the end, which drives a threaded rod with right / left thread, along which the wedge-shaped spacers move to the center of the device, lifting the top wall vertically upwards devices, while two cylindrical pins located in the central part of the device hold the structure together and direct the movement of the upper wall.

Pyramid-shaped protrusions with a height of 1-2 mm, located on the outer surfaces of the upper and lower walls of the device’s body, are introduced into the end plates of the vertebral bodies with increasing height of the device, thereby fixing them. The increase in the height of the intervertebral gap is controlled by x-ray monitoring. Upon reaching the desired result, the device is disconnected from the tool for installation.

Example. Patient M., 33, medical history No. 21 236785, was admitted to the hospital on 05/17/2010 with complaints of pain in the lumbar spine with radiation to the left lower limb, restriction of movements in the lumbar spine. On examination, there was a smoothness of lumbar lordosis, pain on palpation of the spinous processes of L4, L5 vertebrae, a positive symptom of Laseg (angle of 25 degrees). MRI scans revealed a herniation of the intervertebral disc L4-L5, compressing the left spinal root.

05/20/2010, the operation was performed: Microsurgical discectomy L4-L5, fixation of the vertebrae of the proposed device.

Operation progress: by a linear incision 4 cm long, the arches L4, L5 of the vertebrae on the left and the left intervertebral joint L4-L5 are laid out in layers. A flavectomy of L4-L5 was performed; a herniation of the intervertebral disc L4-L5 was detected, compressing the spinal root of L5. The microelevator discharged the medially root and dural sac, using the forceps-grabs, removed fragments of the disk substance that compressed the root. Diskectomy performed. With the help of Kerrison's bone nippers, a partial resection of the L4-L5 intervertebral joint was performed. Using the curette, partial removal of the end plates from the adjacent surfaces of the L4, L5 vertebrae was performed.

In the prepared device, through the oval windows on the upper and lower sides of the body, a bone autocrush previously processed in a bone mill was introduced into the body of the body. The device was mounted on a tool for its installation. Then, through the formed hole under X-ray monitoring, the device was introduced into the anterior intervertebral spaces. After installing the device in the box, clockwise rotational movements were made with a T-shaped screwdriver with a flat section at the end, which set in motion a threaded rod with right / left thread, along which the wedge-shaped spacers moved to the center of the device, lifting the upper wall of the device vertically, thereby increasing the height of the device. Pyramid-shaped protrusions located on the outer surfaces of the upper and lower walls of the device’s body, with an increase in the height of the device, were embedded in the end plates of the vertebral bodies, thereby fixing them. Upon reaching the desired result, the device was disconnected from the tool for its installation.

They installed drainage, sutured the wound in layers. The postoperative period was uneventful. On control radiographs after 10 months, the formation of a bone block between the vertebral bodies is noted.

Thus, 3 operations were performed. This device and the instrument for its installation have been tested in the spinal surgery department of the Russian National Center for Surgery. Academician B.V. Petrovsky RAMS. Received positive results.

Claims (1)

A device for symmetric restoration of the height of the intervertebral space and fixation of the vertebrae on one side, containing a hollow parallelepiped body with oval windows on its upper and lower walls, the front and rear walls of the device having wedge-shaped spacers and a threaded rod having a recess for holding the key in its rear part, in the center of the device from two sides - two pins that hold the structure together and direct the movement of the upper wall, the housing is made with the possibility of vertical opening by moving the wedge-shaped spacers to the center of the device along the threaded rod, the upper wall of the hollow body is made curved, the threaded rod is made with right / left thread, the pins are made cylindrical, on the outer surfaces of the upper and lower walls of the body the bases of the pyramidal protrusions with pyramid heights 1 are evenly located -2 mm.

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