IMPLANT DEVICE FOR PERFORMING POSTERIOR SPINAL ARTHRODESIS AT A FACET JOINT

Abstract

An implant device for performing posterior spinal arthrodesis at a facet joint, includes a flat element, of constant thickness, having, in order to receive a bone graft, a large central opening so as to form a substantially annular shape. The device is intended to be inserted into a cavity previously produced at the location of the facet joint that is to be immobilised. The element is D-shaped, the rounded side constituting the distal edge for insertion into the cavity, while the proximal opposing edge, which is straight, includes a device for securing to a holding and positioning tool. The opposing faces of the flat element have raised areas that include notches arranged perpendicular to the direction of insertion, each of the notches having a tooth profile with two sides.

Claims

1. An implant device for performing a posterior spinal arthrodesis at a facet joint, comprising: a flat element of constant thickness, being comprised of a central opening so as to receive a bone graft, imparting a substantially annular shape, and suitable for being introduced into a cavity made beforehand in the location of the facet joints to be immobilized, wherein said element is D-shaped, the rounded side making up the distal edge for insertion into said cavity, while the opposite, rectilinear proximal edge is comprised of means for securing to a handling and placement tool, and wherein the opposite faces of said flat element include reliefs are comprised of notches arranged perpendicular to the insertion direction, each of the notches having a toothed profile with two faces, one of which, that oriented on the side of said proximal edge, is perpendicular or substantially perpendicular to the main plane of said element, while the other face is inclined.

2. The implant device according to claim 1, wherein the flat element has, on the side of its rounded distal edge, a thickness that decreases, so as to impart a corner profile to this distal edge.

3. The implant device according to claim 1, wherein the means for securing to a handling and placement tool consists of a tapped hole, with axis parallel to the insertion direction.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0017] In the appended drawings:

[0018] FIG. 1 shows a planar view of the implant device according to the invention.

[0019] FIG. 2 shows a sectional view along axis AA of FIG. 1.

[0020] FIG. 3 shows a schematic view of the same implant in position after implantation, the right side between vertebrae L5 S1, and along the insertion direction.

[0021] FIG. 4 shows a schematic view of the same implant in the same position, but shown transparently and along a perpendicular plane.

DETAILED DESCRIPTION OF THE INVENTION

[0022] In reference to FIGS. 1 and 2, an implant device 1 is shown for performing an arthrodesis at a facet joint according to the invention.

[0023] It will be noted beforehand that the implant device 1 according to the invention is made, non-limitingly, from titanium.

[0024] This implant device 1 is substantially flat, as shown more specifically in FIG. 2, and assumes the shape of a D. It thus has a rounded distal side 2 and a straight proximal side 3, whereas centrally, a wide space 4 is freed.

[0025] Each of the two faces 5 and 6 of the implant device 1 is trimmed with notches 7 aligned transversely relative to the axis AA, suitable for performing anchoring in the bone material. As can be seen in FIG. 2, each of the notches 7 comprises two faces, a face 8 arranged on the straight proximal side 3 and which is perpendicular or substantially perpendicular to the main plane of the implant device 1, and a face 9 arranged on the distal side 2, and which is inclined.

[0026] In this same FIG. 2, one can also see that, on the distal side 2, the two faces 5 and 6 come closer together, so as to give this distal side 2 a corner profile.

[0027] One can also see in these figures that the part 10 of the implant device 1, forming the proximal side 3, is pierced, along the axis AA, with a hole 11, tapped to allow it to be subjected to the end of a placement tool.

[0028] In reference now to FIGS. 3 and 4, one can see an implant device 1 according to the invention placed in the location of the facet joint between vertebrae L5 and S1, the right side of which is partially shown, knowing that the left side, not shown, is equipped in the same way.

[0029] Before the placement, the bone material of the two vertebrae is cut out, at the facet joint, so as to create a cavity C, shared between the two vertebrae, in this case L5 and S1, and extending in the contact plane.

[0030] Then, the implant device 1 is introduced into the cavity C, after having deposited a bone graft in its space 4.

[0031] The introduction of the implant device 1 is done along the direction of the arrow S shown in FIG. 4, that is to say, parallel to the axis AA of FIG. 1 and by engaging the corner-shaped distal side 2 first.

[0032] The implant device 1 according to the invention is very simple to produce and implement.