Intervertebral disk prosthesis
First Claim
1. An implantable intervertebral disk member for use as a replacement of a natural intervertebral disk between two adjacent vertebras of a spinal cord of a patient, the disk member comprising a one-piece body shaped and dimensioned to substantially conform to that of the natural disk it is to replace and forming spaced-apart, upper and lower attachment surfaces for connection of the disk member to the adjacent vertebras, the body being made of a solid, elastically deformable material and having a unitary construction, the body including a plurality of parallel slits oriented at a right angle to an axis of the disk member, the slits extending into the body to a sufficient depth so that proximate slits partially overlap and thereby define overlapping regions forming portions of leaf springs adapted to transmit bending forces, weight loads and shear loads applied to the disk member by the adjacent vertebras when the disk member is implanted in a patient'"'"'s spinal cord.
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Accused Products
Abstract
An intervertebral disk prosthesis is described which with respect to its external dimensions imitates a natural intervertebral disk and connects two adjacent vertebrae to their upper and lower attachment surfaces. The intervertebral disk member is made of one piece from a strong, elastically deformable material and comprises parallel slits at a right angle to the connecting axis which partially overlap. In overlapping regions adjacent slits form parts of leaf springs for the transmission of forces from one attachment surface of the prosthesis to the other attachment surface.
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Citations
15 Claims
- 1. An implantable intervertebral disk member for use as a replacement of a natural intervertebral disk between two adjacent vertebras of a spinal cord of a patient, the disk member comprising a one-piece body shaped and dimensioned to substantially conform to that of the natural disk it is to replace and forming spaced-apart, upper and lower attachment surfaces for connection of the disk member to the adjacent vertebras, the body being made of a solid, elastically deformable material and having a unitary construction, the body including a plurality of parallel slits oriented at a right angle to an axis of the disk member, the slits extending into the body to a sufficient depth so that proximate slits partially overlap and thereby define overlapping regions forming portions of leaf springs adapted to transmit bending forces, weight loads and shear loads applied to the disk member by the adjacent vertebras when the disk member is implanted in a patient'"'"'s spinal cord.
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13. An implantable intervertebral disk member for implantation in a spinal cord of a patient between two adjacent vertebras of the spinal cord and as a replacement of a natural intervertebral disk of the spinal cord, the disk member comprising a unitary body with an attachment surface for attachment to the adjacent vertebras, made of a high strength, elastically deformable material, a plurality of narrow slits extending from a periphery of the body into and terminating in slit base at an interior of the body to thereby define a plurality of leaf springs spaced apart by the slits in an axial direction of the disk member, the leaf springs being secured to each other at inflexible regions defined by the body and proximate the slit bases, the inflexible regions between proximate leaf springs being offset with respect to each other so that the application of a force acting in an axial direction results in deflections of the attachment surfaces, whereby, upon the implantation of the disk member in the spinal cord of a patient, the disk member maintains the adjacent vertebras spaced apart and permits relative movement of the adjacent vertebras in a manner approximating the manner in which the natural intervertebral disk it replaces permits such relative movements.
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14. An implantable intervertebral disk member for use as a replacement of a natural intervertebral disk between two adjacent vertebras of a spinal cord of a patient, the disk member comprising a one-piece body shaped substantially the same as the natural intervertebral disk it is to replace and forming spaced-apart, upper and lower attachment surfaces for connection of the disk member to the adjacent vertebras, the body being made of a solid, elastically deformable material and having a unitary construction, the body including a plurality of parallel slits oriented at a right angle to an axis of the disk member, the slits extending into the body to a sufficient depth so that proximate slits partially overlap and thereby define overlapping regions forming portions of leaf springs adapted to transmit forces applied to the disk member by the adjacent vertebras when the disk member is implanted in a patient'"'"'s spinal cord, whereby the application of a force to the attachment surfaces causes a controlled deflection of the leaf springs and a corresponding deflection of the attachment surfaces so that the disk member deflects and thereby acts similar to the natural intervertebral disk which it replaces when the disk member is implanted between the adjacent vertebras.
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15. An implantable intervertebral disk prosthesis comprising a body shaped and dimensioned to correspond to the shape and dimension of a natural intervertebral disk which it replaces, for placement between two adjacent vertebras, the body having an upper attachment surface being made in one piece from an elastically deformable material, and including parallel slits at a right angle to an axis of the prosthesis which partially overlap so that in an overlapping region a leaf spring is formed to transmit forces from the upper attachment surface to the lower attachment surface, the attachment surfaces converging in a wedge shape from a ventral side to a dorsal side of the intervertebral disk prosthesis.
Specification