| 摘要 |
Intervertebral disc prosthesis includes an upper plateau (16) with an outer surface (16a) bearing on an upper vertebra and with a surface (16b) directed towards the inside of the prosthesis, a lower plateau (18) with an outer surface (18a) bearing on a lower vertebra and with a surface (18b) directed towards the inside of the prosthesis, and a ball-type joint between the upper plateau and the lower plateau, having a bulged convex element (27), cooperating with a complementary recess of the bulged convex element (27) and coming into contact with the bulged convex element (27), the bulged convex element (27) including at least one slot (24, 25, 26, 28) that allows it to deform. |
| 主权项 |
1. An intervertebral disk prosthesis, comprising:
an upper plateau (16) having i) an upper external surface (16a) capable of bearing on an upper vertebra, ii) a lower surface (16b) directed downwardly, and iii) a upwardly convex depression within the lower surface (16b); a lower plateau (18) having i) a lower external surface (18a) capable of bearing on a lower vertebra, ii) an upper bearing surface (18b) directed upwardly towards the lower surface (16b) of the upper plateau (16), the upper bearing surface (18b) being comprised of an upwardly concave-shaped surface part (22) surrounded by a flat part (23), and iii) an upwardly extending edge (19) delimiting the flat part (23) of the upper bearing surface (18b) of the lower plateau (18), a region open to an environment outside of the intervertebral disk prosthesis being present between the lower surface (16) of the upper plateau (16) and the top edge surface of the upwardly extending edge (19) such that a part of the flat part (23) delimited by the upwardly extending edge (19) is open to the environment outside of the intervertebral disk prosthesis; and an intermediate part (20) comprising an upper surface defined by a spherical upwardly convex domed part (27) and a lower surface, the intermediate part (20) being located between the lower surface (16b) of the upper plateau and the upper bearing surface (18b) of the lower plateau, the upwardly convex domed part (27) being in movable contact with the upwardly convex depression within the lower surface (16b) of the upper plateau (16), the lower surface of the intermediate part (20) being carried by direct contact with the flat part (23) of the upper bearing surface (18b) of the lower plateau (18), the intermediate part (20) being laterally movable on an area of the flat part (23) of the upper bearing surface (18b) of the lower plateau (18) delimited by the upwardly extending edge (19); and a lumen (25) defined by the upwardly concave-shaped surface part (22) of the upper bearing surface (18b) of the lower plateau (18) and a portion of the lower surface of the intermediate part (20), wherein upon a vertical impact on the upwardly convex domed part (27) of the intermediate part (20) during sudden or vibratory movements in everyday life, elasticity of the intermediate part (20) allows deformation of the upwardly convex domed part (27) of the intermediate part (20) to at least partial fill the lumen; and wherein the flat part (23) of the upper bearing surface (18b) of the lower plateau (18) is located around the upwardly concave-shaped surface part (22) of the upper bearing surface (18b) of the lower plateau (18), and a surface ratio between the upwardly concave-shaped concave part (22) and the flat part (23) of the upper bearing surface (18b) is in a range between 1/4 and 3/4. |
