Intervertebral implant

An intervertebral implant for implantation between an upper and lower vertebrae, the implant having a central axis, the implant comprising:

• a first substantially rigid bone contacting plate having an external surface extending generally transversely to the central axis for contacting at least a portion of the upper vertebra;
• a second substantially rigid bone contacting plate having an external surface extending generally transversely to the central axis for contacting at least a portion of the lower vertebra;
• a third plate operatively coupled to the first bone contacting plate, the third plate including a plurality of openings;
• a fourth plate operatively coupled to the second bone contacting plate, the fourth plate including a plurality of openings;
• a central part substantially located between the third and fourth plates, the central part including a flexible core and a fiber system, wherein the core is substantially cylindrical and includes a top surface and a bottom surface, the top surface of the core being in contact with the third plate and the bottom surface of the core being in contact with the fourth plate, and wherein the fiber system at least partially surrounds the core, and is at least partially received within the plurality of openings formed in the third and fourth plates so that the fiber system is joined to the third and fourth plates;
• and
• an elastic sheathing body at least partially surrounding the fiber system and the core, and connected to the third and fourth plates.

An intervertebral implant for implantation between adjacent vertebrae, the implant having a central axis, the implant comprising:

• a bottom closing plate having an external surface extending generally transversely to the central axis for contacting at least a portion of one of the adjacent vertebrae;
• a bottom cover plate in contact with the bottom closing plate, wherein at least one of the bottom closing plate and the bottom cover plate is substantially rigid;
• a top closing plate having an external surface extending generally transversely to the central axis for contacting at least a portion of the other adjacent vertebrae;
• a top cover plate in contact with the top closing plate, wherein at least one of the top closing plate and the top cover plate is substantially rigid;
• a central part provided between the top and bottom closing plates, the central part including a fiber system and a core, the fiber system being at least partially joined to the cover plates, and at least partially surrounding the core, and
• a sheathing comprising an elastic sheathing body, the sheathing body at least partially surrounding the central part and being connected to the top and bottom cover plates;
• wherein the core is an elastically formed body having a cavity, the cavity being filled at least partially with an incompressible liquid, the liquid being at least partially surround by the elastic formed body;
• and
• wherein the elastic formed body is surrounded by a semi-permeable membrane.