INTERVERTEBRAL DISK PROSTHESIS Russian patent published in 2010 - IPC A61F2/44 

FIELD: medicine.

SUBSTANCE: prosthesis comprises at least two plates, namely the first and second plates to be pivotally turnable relatively to each other by a core having a flat surface and a curvilinear surface of the pivotal turn. The first plate contains a curvilinear surface of the pivotal turn interacting with at least one part of the curvilinear surface of the core whereto interfaced to enable the turn and/or inclination of one plate relatively to another. The flat surface of the core interacts with at least one part of the flat surface of the second plate to ensure translation and/or rotation of the core relatively to the second plate at least in the same one direction perpendicular to a vertical axis of the spine column. The second plate contains interaction mechanisms interfaced to core interaction mechanisms ensuring limitation or cancellation of at least core translation relatively to the second plate. The mentioned curvilinear surfaces of the pivotal turn have an apex vertically matched with the centre of the pivotal turn of the prosthesis. Each plate contains edges and surface known as a contact surface designed to ensure the contact with the vertebral plate of one of vertebras between which the prosthesis is supposed to be implanted. The mentioned contact surface for each plate contains a geometrical centre equispaced from at least two opposite points on a periphery of the plate. The centre of the pivotal turn of the prosthesis is vertically matched with the apex of the curvilinear surface of the pivotal turn of the core corresponding to the core neutral position between the interaction mechanisms of the second plate and to the neutral position of the centre of the curvilinear surface of the first plate relatively to the core. The centre of the pivotal turn is vertically matched with the geometrical centre of the first plate, however the core neutral position between the interaction mechanism of the second plate is displaced relatively to the geometrical centre of the second plate at least in the same direction perpendicular to a vertical axis of the spine column, and hence, the centre of the pivotal turn is displaced relatively to the geometrical centre of the second plate. The contact surfaces of two plates have essentially equal sizes, and plate edges are also displaced at least in the same direction perpendicular to a vertical axis of the spine column.

EFFECT: invention provides prevention of vertebral plate damage with a prosthesis by creation of the surface of the pivotal turn.

23 cl, 5 dwg