RU2321371C1 - Reposition spinal column lock - Google Patents

Abstract

FIELD: medicine; neurosurgery; traumatology.

SUBSTANCE: reposition spinal column lock can be used for reclination and fixation of vertebras at breaks. Vertebrae lock has bars with fitting elements in form of mono-axial threaded rods and cross-arm with hooks equipped with threaded stops for being fixed onto bars. Rods have cylindrical heads with external thread at top part and threaded opening along axis, which opening opens in direction of horizontal through opening made in base of head in perpendicular to longitudinal axis intended for pin. Pin is disposed at base of cylindrical lock onto external surface in perpendicular to longitudinal axis. Fixer has dead threaded opening at axis intended for stop screw and open through groove along same axis. Forces are applied selectively, which forces are reverse to compression forces acting on bodies of vertebras.

EFFECT: higher results of treatment.

2 dwg

Description

The invention relates to medicine, namely to neurosurgery and traumatology, and is intended for reclamation and fixation of vertebrae in case of fractures.

Various devices are known for fixing during vertebral fractures, such as, for example, a repositional-distraction apparatus [1] containing elements from the Ilizarov set: threaded rods installed in brackets, racks, self-tapping rods and rods with stops.

This device finds its application in the treatment of chronic fractures, the treatment of kyphoscoliotic disease. Patients are in the hospital for a long time, the risk of infectious complications is high. At the end of the hardware treatment, after removing the external fixation device, there is a need for an additional operation to install the fixing device.

Another analogue is a device for posterior fusion [2], which contains bone screws mounted on a threaded rod using plates with tides and rings. The design attempt was made to maximize the technical capabilities of external fixation devices to the capabilities of immersion systems. The disadvantage of this analogue is the small length of the lever, which reduces the efficiency of use of this system.

Closest to the proposed fixative in its technical solution is the Stryker spinal stabilization system [3], which is a set of polyaxial transpedicular bone screws with split heads connected by smooth longitudinal rods through a cage system.

The inability to breed bone screws in the distal parts is the main drawback of this system, which results in a lack of forces opposite to the compression forces on the vertebral bodies. Conducting distraction by diluting the heads of the threaded rods along a smooth longitudinal rod ensures elongation of the surface of the vertebral bodies along the line of the spinous processes and leads to their decrease along the front line. The restoration of the vertebral body during its fracture occurs only as a result of the patient's correct placement on the operating table, with his head or legs raised, and not from the effects of the forces applied to the elements of the device.

The invention is expressed in the aggregate of essential features sufficient to achieve the desired technical result, namely, improving treatment outcomes due to the selective application of forces that are inverse to the compression forces acting on the vertebral bodies. The result is achieved due to a more efficient reposition of the compressed vertebra with an atraumatic effect on damaged structures.

This essence lies in the fact that the repositional retainer of the spine contains rods with fastening elements in the form of monoaxial threaded rods and a cross bar with hooks equipped with threaded stoppers for fixing on the rods. The rods have a cylindrical head with an external thread in the upper part and a threaded hole along the axis, opening into a horizontal through hole made in the base of the head, perpendicular to the longitudinal axis, under the pin. The pin is located at the base of the cylindrical retainer, on the outer side surface, perpendicular to the longitudinal axis, having a blind threaded hole along the axis of the locking screw and an open through groove along the same axis.

The external thread on the top of the head of the monoaxial rod is designed to install a screwdriver, with which the rod is inserted into the vertebral body.

A threaded hole along the axis of the head of the rod, opening in a horizontal through hole made in the base of the head perpendicular to the longitudinal axis, is necessary for installing and fixing the distractor, which provides an impact on the vertebral bodies. This hole is also intended to install a locking screw securing the pin of a cylindrical retainer in the head of the rod after distraction of the vertebrae.

The presence of a horizontal hole in the base of the head of the threaded rod, perpendicular to the longitudinal axis, and a pin made on the outer side surface in the base of the cylindrical retainer, ensures the unity of the design of the rod and the retainer while maintaining the freedom of rotation of these parts relative to each other around the axis of the rod.

An open through groove along the axis of the latch is designed to install a smooth-walled rod, and a blind threaded hole along the same axis is used to install a locking screw securing the latch to the rod.

The advantages of the proposed device should include optimal reclamation of the damaged vertebra with the possibility of full restoration of the anterior spine.

The device is illustrated by a spatial image in figure 1; figure 2 shows a front view in combination with a frontal section of a monoaxial bone rod and retainer.

Monoaxial bone rods 1 has a head 2 with an external thread 3. Along the axis of the rod 1 in the head 2 there is a threaded hole 4 for the locking screw 5. At the base of the head there is a horizontal through hole 6 with an axis perpendicular to the axis of the rod 1, under the cylindrical pin 7. Pin 7 is located at the base of the cylindrical retainer 8, on its outer side surface, the axis of the pin 7 is perpendicular to the longitudinal axis of the retainer 8, along which there is a blind threaded hole 9 for the locking screw 10 and an open through groove 11 for scheniya rods 12. The rods are interconnected by a rectangular crosspiece 13 with hooks 14, equipped with threaded stoppers 15 for fixing on the rods 12.

The device is used as follows. Access to the posterior spine according to standard methods. After exposure of the spinous processes and adjacent arches of the damaged vertebra, as well as at least two above- and underlying vertebrae, above and below the level of damage, monoaxial threaded rods 1 are installed using a socket screwdriver. When installing the rods 1 horizontal holes 6 in the base of the heads 2 must be oriented perpendicular to the axis of the spine. The rod 12 is installed in the open slots 11 of the latches 8, slightly secured with the locking screws 10 and, moving the latches 8 along the rod 12, insert the pins 7 of the latches 8 into the horizontal holes 6 of the rods 1, after which the locking screws 10 are finally fixed in the holes 9 of the latches 8. Next By moving the handle of a screwdriver mounted on the head of a threaded monoaxial rod to the lesion, they alternately affect the bodies of all vertebrae. The simulated position is fixed with a screwdriver, securing the locking screw 5 in the threaded hole 4 of the head 2, thereby achieving the effective reclamation of the damaged vertebra. For the most complete and reliable stabilization of the area of damaged segments, the rods 12 are fastened together by a rectangular cross member 13 with hooks 14 and threaded stoppers 15, creating a single design. The surgical wound is sutured in layers tightly.

Information sources

1. Tumakaev R.F. Surgical treatment of complicated injuries of the lower thoracic and lumbar spine // Diss ... cand. honey. sciences. - Kazan. - 2004. - P.76-82.

2. RF patent No. 2218122, A61B 17/70, 17/80, BIPM, 2003, No. 34.

3. XIA spinal system. Operative technique, universal Application // Stryker spine. - 2005. - 20 p.

Claims (1)

Repositional spinal retainer containing rods with fastening elements in the form of threaded monoaxial rods, interconnected by a cross with hooks equipped with threaded stoppers for fixing on rods, characterized in that the rods have a cylindrical head with an external thread in the upper part and a threaded hole along the axis, opening into a horizontal through hole made at the base of the head, perpendicular to the longitudinal axis, under the pin located at the base of the cylindrical retainer, on ruzhnoy, a side surface perpendicular to the longitudinal axis, having a threaded blind hole along the axis for the locking screw and open through slot along the same axis.

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