INTERVERTEBRAL DISK ENDOPROSTHESIS Russian patent published in 2017 - IPC A61F2/44 

FIELD: medicine.

SUBSTANCE: intervertebral disc end prosthesis consists of three parts, a lower plate, an upper plate and a central part located between the plates. The upper and lower plates, each, have cylindrical cavities located to the central part. The central part is a pair of conjugations consisting of two conjugation elements. The first conjugation element is in the form of a ball segment with a convex-spherical sliding surface having an edge in the cylindrical shape with its protruding part and height for placement in the cylindrical cavity of the lower plate. The height of the edge and the depth of the edge of the cylindrical cavity have a ratio of 1:3. Edge and edge form a limiting element. The second conjugation element installed in the cylindrical cavity of the upper plate from its underside, is in the form of a cylindrical block whose edge height and the depth of the edge of the cylindrical cavity have a ratio of 3.8:3.0. The conjugation element has a notch with a concave-spherical sliding surface from the lower side, the radius of which is equal to the radius of the convex-spherical sliding surface of the spherical segment. The possibility of sliding surface movement along the sliding surface is restricted by this limiting element, at which the surface of the lower plate edge is fixed to the surface of the upper plate edge. It is possible to move along the spherical surfaces in all directions and rotate with the deflection of the spherical segment and the concave spherical notch axes relative to each other within the range of 8-12°. The lower and upper plates are made of porous oxide ceramics based on alumina or zirconium oxide with surface porosity of at least 40%, with an average pore size of at least 150 mcm. The first conjugation element is made of dense ceramics based on alumina with a density of 3.8-3.9 g/cm³, or zirconium oxide with a density of 6.0-6.1 g/cm³. The second conjugation element is made of UHMWPE.

EFFECT: invention provides stability of the spinal column and a decrease in the effect of wear particles of the materials from which the end prosthesis elements are made on the living organism.

6 cl, 7 dwg