Artificial intervertebral disc with lower height
The disclosure provides an intervertebral disc and related methods. An upper plate includes an upper vertebra contacting portion and a lower bearing surface portion. The upper vertebra contacting portion includes a convex central portion, and a fin or anchoring element with a transverse hole therethrough. A lower plate has a lower vertebra contacting surface and an upper bearing surface. The lower vertebra contacting surface of the lower plate has a convex central portion. The upper bearing surface has a concavity disposed opposite the convex central portion and wherein the convex central portion and the concavity have nesting curvatures. A core positioned between the upper and lower plates has rigid upper and lower convex surfaces configured to slide and translate over the bearing surfaces of the upper and lower plates.
1 . An intervertebral disc comprising:
an upper plate having an upper vertebra contacting portion and a lower bearing surface portion, wherein the upper plate includes a convex central portion and is made of PEEK;
a lower plate having a lower vertebra contacting portion and an upper bearing surface portion, wherein the lower plate is made of PEEK; and
a rigid core positioned between the upper and lower plates, the core configured to slide and translate over the upper bearing surface and the lower bearing surface portion, wherein the rigid core is ceramic,
wherein the upper plate includes a fin disposed on the upper vertebra contacting portion that has a length greater than a height,
wherein the upper vertebral contacting surface and the lower vertebral contacting surface include three finlets on opposing sides of the fin,
wherein the finlets extend in height greater than teeth positioned on the upper vertebral and lower vertebral contacting surfaces, and each finlet includes top surface,
wherein each of the finlets have an anterior surface formed at an angle of about 70 to 90 degrees, preferably about 80 degrees, a posterior surface formed at an angle of about 50-70 degrees, preferably about 60 degrees, and the top surface formed at an angle of about 2-20 degrees, each with respect to the upper and lower vertebral contacting portions.
2 . The intervertebral disc of claim 1 , wherein the upper vertebra contacting portion includes a metal and the lower bearing surface portion includes an MRI compatible material.
3 . The intervertebral disc of claim 1 , further comprising a plurality of teeth on the upper vertebra contacting portion of the upper plate and the lower vertebra contacting surface of the lower plate.
4 . The intervertebral disc of claim 1 , wherein each of the upper plate and the lower plate include dome shaped portions convex central portions.
5 . The intervertebral disc of claim 4 , wherein the dome shaped portions have a diameter of about 5 to about 20 nm.
6 . The intervertebral disc of claim 4 , wherein at least one of the dome shaped portions has a diameter less than a diameter of the core.
7 . The intervertebral disc of claim 4 , wherein the convex central portion of the upper plate is raised relative to a generally planar peripheral portion of the upper plate.
8 . The intervertebral disc of claim 1 , wherein the upper vertebra contacting portion and the lower vertebra contacting surface are titanium plasma sprayed.
9 . A method of implanting an intervertebral disc between adjacent vertebrae in place of a damaged disc, the method comprising:
providing the intervertebral disc including:
an upper plate having an upper vertebra contacting portion and a lower bearing surface portion, wherein the upper plate is made of PEEK,
a lower plate having a lower vertebra contacting surface and an upper bearing surface, wherein the lower plate is made of PEEK, and
a rigid core positioned between the upper and lower plates, the core configured to slide and translate over the upper bearing surface and the lower bearing portion, wherein the rigid core is ceramic;
grasping the upper and lower plates of the disc with an instrument by simultaneously grasping the plates at grooves to hold the plates in a locked orientation; and
inserting the intervertebral disc between the adjacent vertebrae with the upper and lower plates held in the locked orientation by the instrument
wherein the upper vertebral contacting portion and the lower vertebral contacting portion include three finlets on opposing sides of the fin,
wherein the finlets extend in height greater than teeth positioned on the upper vertebral and lower vertebral contacting portion, and each finlet includes top surface,
wherein each of the finlets have an anterior surface formed at an angle of about 70 to 90 degrees, preferably about 80 degrees, a posterior surface formed at an angle of about 50-70 degrees, preferably about 60 degrees, and the top surface formed at an angle of about 2-20 degrees, each with respect to the upper and lower vertebral contacting portions.
10 . The method of claim 9 , wherein the upper vertebra contacting portion includes a metal and the lower bearing surface portion includes an MRI compatible material.
11 . The method of claim 9 , further comprising a plurality of teeth on the upper vertebra contacting portion of the upper plate and the lower vertebra contacting surface of the lower plate.
12 . The method of claim 9 , wherein each of the upper plate and the lower plate include a convex central portions that are dome shaped portions.
13 . The method of claim 12 , wherein the dome shaped portions have a diameter of about 5 to about 20 nm.
14 . The method of claim 12 , wherein at least one of the dome shaped portions has a diameter less than a diameter of the core.
15 . The method of claim 12 , wherein the convex central portion of the upper plate is raised relative to a generally planar peripheral portion of the upper plate.
16 . The method of claim 9 , wherein the upper vertebra contacting portion and the lower vertebra contacting portion are titanium plasma sprayed.