ES2275382B1 - TRANSPEDICULAR VERTEBRAL FIXING SYSTEM. - Google Patents

Abstract

Transpedicular vertebral fixation system that by means of transpedicular screws and bars as longitudinal elements with a connection system between both multidirectional type and with a single tightening by the most posterior part of the vertebra, achieves a blockage of the bar in the screw head in Any direction and guidance. This system is indicated for spinal fusion as a treatment for traumatic or degenerative disorders of the spine.

Description

Spinal fixation system transpedicular

Object of the invention

The present invention aims at a transpedicular vertebral fixation system, by means of transpedicular screws and bars as longitudinal elements with a connection system between both multidirectional type and with a single tightening by the most posterior part of the vertebra, thus achieving the bar lock on the screw head in any direction and orientation. This system is indicated for spinal fusion as a treatment for traumatic or degenerative disorders of the spine, at the thoracic, lumbar or
sacrum.

Background of the invention

To this day, some have been used transpedicular screws that in some cases have the axis of the bar on the screw and in other cases said bar axis is It is lateralized, having those indicated first higher profiles than those indicated in second place. It's easily understandable that the above implies a series of problems at the time of use in terms of manageability and occupation of a space that is not always available. To avoid the problems that arise with the use of known systems and by therefore improve what already exists, the purpose of the present invention that has four components being one of tighten to fix the entire system, which in addition to having freedom of rotation around the bar, allows angulation of the transpedicular screw in the sagittal plane of approximately 30 degrees. We will explain all this below.

Description of the invention

The vertebral fixation system that concerns us it is formed by:

1.- Transpedicular screws, with a soul tapered in the threaded section to give it more rigidity, so that The thread profile disappears from the tip to the base. The screw head has a spherical shape for the seat of the flange, outer hexagon for placement in bone, threaded shaft for placement of the nut-washer and hexagon inside for clamping during the tightening of the nut-washer.

2.- Flange: It is the connecting piece between the transpedicular screws and bars so that when placed hugging the screw and letting the bar go by and putting then the nut washer assembly allows the mooring of the bar blocking it in the screw head. It has for the screw a spherical seat allowing the whole set of orientations Space It consists of:

       \ dotable {\ tabskip \ tabcolsep # \ hfil \ tabskip0ptplus1fil \ dddarstrut \ cr} {
 2A - Screw angulation slot. \ Cr 2B -
   Toothed for angular locking of the washer
 \ hskip0,7cm dela. \ cr 2C - Reduction for
nut positioning- \ cr \ hskip0,7cm
washer. \ cr 2D - Spherical seat for the head of the
screw. \ cr 2E - Tightening hole of the
bar \ cr}
    

3.- Nut-washer: It is the piece which tightens the assembly in such a way that the nut rotates freely Regarding the washer. Once the tightening has begun and with the first threads the washer is self-positioned on the Flange recesses. The washer has two tabs for self-position on the flange and two serrated areas for blocking angle of the flange over the screw head. The set of Both prevent angular movement of the bar.

4.- Longitudinal bar is the connecting element between the transpedicular screws so that you can be modeled to fit the position of the different screws that make up the system.

Description of the drawings

To complement the description that is being performing and in order to help a better understanding of the characteristics of the invention, is accompanied herein descriptive, as an integral part of it, of a game of drawings, where illustrative and non-limiting nature has been represented the following:

Figure 1 shows a transpedicular screw with nut and washer.

Figure 2 shows a flange.

Figure 3 shows a nut assembly and washer.

Figure 4 shows all the pieces in positioning as they will be placed.

Figure 5 shows the pieces placed Finally.

Preferred Embodiment of the Invention

To use the fixing system of the present invention, the screws (1) are first placed in the appropriate place with the aid of the corresponding instruments (not shown). Then the flanges (3) are threaded with the bar (4) already in place, on the handles (guide tools for mounting assistance) (2) of the screws (1), so that the flanges (3) slide to the head of the corresponding screw and then orient the flange (3) according to the angle of the screw (1) until the bar (4) is placed in the desired position. The nut-washer assembly (5) that slides through the handle (2) to the head of the screw (1) is then introduced so that when the threading starts the tabs of the nut-washer assembly (5) are self-positioned on the recess (31) of the flange (3). The nut is threaded until the system is tightened and the position of the flange can be readjusted in relation to the screw. During this threading process, the screw (1) is held by its internal hexagon to prevent rotation inside the pedicle, having previously disassembled the
handle (2).

It is not considered necessary to extend this description so that any subject matter expert understands the scope of the invention and the advantages derived therefrom. The terms in which this report has been written must be always taken in a broad and non-limiting sense.

The materials, shape, size and layout of the elements will be subject to variation as long as it do not involve an alteration of the essential characteristics of the invention claimed below.

Claims (9)

1. Transpedicular vertebral fixation system, of the type used in surgical interventions, characterized in its form because it consists of transpedicular screws, flange, nut-washer assembly and longitudinal bar. 2. Transpedicular vertebral fixation system, according to the first claim, characterized in that the flange allows the bar to be moored and locked on the screw head in any direction and orientation. 3. Transpedicular vertebral fixation system, according to the preceding claims, characterized in that the flange consists of a groove for its angulation on the screw, toothed for the angular lock of the nut-washer, recess for the positioning of the nut-washer, spherical seat for screw head and bar tightening hole. 4. Transpedicular vertebral fixation system, according to the preceding claims, characterized in that the nut-washer is the part that tightens the assembly so that the nut rotates freely with respect to the washer. 5. Transpedicular vertebral fixation system, according to the preceding claims, characterized in that the washer has two flanges for self-positioning on the flange and two serrated areas for angular flange blocking and the assembly of both prevents angular movement of the bar after tightening. 6. Transpedicular vertebral fixation system, according to the preceding claims, characterized in that the longitudinal bar is the connecting element between the transpedicular screws so that it can be modeled to adapt to the position of the different screws that make up the system. 7. Transpedicular vertebral fixation system, according to the preceding claims, characterized in that the head of the transpedicular screw has a spherical shape for the seat of the flange, outer hexagon for placement in the bone, threaded shaft for the placement of the nut-washer and internal hexagon for fastening during tightening of the nut-washer. 8. Transpedicular fixation system, according to the preceding claims, characterized in that the thread of the transpedicular screw has a conical core for greater rigidity thereof. 9. Transpedicular fixation system, according to the preceding claims, characterized in that the only closing of the flange on the screw head when threading the nut-washer causes the blockage of all possible movements of the bar with respect to the screw.