Abstract: The device for maintaining an intervertebral space is capable of being accommodated inside the disc, in place of the core. Natural anchoring is ensured by promoting the regrowth of fibre around at least part of the device. The possibility of ejection of the residual core is limited in order to avoid a renewed hernia, and mobility of the vertebral column is ensured. To this end, a subject of the invention is a device having at least two non-expansible concentric rings which between them form a free space and which are connected to each other via two junction summits.

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.

Abstract: The device for maintaining an intervertebral space is capable of being accommodated inside the disc, in place of the core. Natural anchoring is ensured by promoting the regrowth of fibre around at least part of the device. The possibility of ejection of the residual core is limited in order to avoid a renewed hernia, and mobility of the vertebral column is ensured. To this end, a subject of the invention is a device having at least two non-expansible concentric rings which between them form a free space and which are connected to each other via two junction summits.