Intervertebral disc replacement
The present invention is an intervertebral disc replacement for replacing a disc between a first vertebra and a second vertebra including an upper containment structure adapted to contact a lower surface of a first vertebra, a lower containment structure adapted to contact an upper surface of a second vertebra, where the upper and lower containment structures are adapted to centrally contain a deformable support body positioned between the upper and lower containment structures.
1 . An intervertebral disc replacement for replacing a disc between a first vertebra and a second vertebra comprising:
an upper containment structure adapted to contact a lower surface of a first vertebra;
a lower containment structure adapted to contact an upper surface of a second vertebra;
the upper and lower containment structures adapted to centrally contain a deformable support body positioned between the upper and lower containment structures.
2 . The disc replacement of claim 1 wherein the upper and lower containment structures are comprised of a polymer having a hardness in the range of about 100 to 130 Rockwell R.
3 . The disc replacement of claim 2 wherein the polymer is polyetheretherketone polymer.
4 . The disc replacement of claim 3 wherein the polyetheretherketone polymer is porous having sufficient pore size to allow bone in-growth.
5 . The disc replacement of claim 1 wherein the support body is comprised of a polymer having a durometer in the range of about 35 to 95 Shore A or 50 to 75 Shore D.
6 . The disc replacement of claim 1 wherein the support body is deformable in response to surface features on the upper and lower containment structures.
7 . The disc replacement of claim 1 wherein the support body conforms to the shape of the upper and lower containment structures.
8 . The disc replacement of claim 1 wherein the support body has a compressive modulus in the range of about 14 to 25 MPa.
9 . The disc replacement of claim 1 wherein the upper and lower containment structures have a compressive modulus in the range of about 3,000 to 7,000 MPa.
10 . The disc replacement of claim 1 wherein the support body is attached to at least one of the upper and lower containment structures prior to insertion between the vertebrae.
11 . The disc replacement of claim 1 wherein at least one of the upper and lower containment structures include a containment structure adapted to contain the support body.
12 . The disc replacement of claim 1 wherein the support body may be shaped to limit torque.
13 . The disc replacement of claim 1 wherein the support body is generally configured in a wedge shape and the containment structures are generally configured in a corresponding wedge shape.
14 . The disc replacement of claim 1 further including fibrous PEEK adapted to be wrapped around the periphery of the disc replacement.