Porous intervertebral distraction spacers
View Patent ↗An intervertebral space distraction and implantable device assembly provides sequentially axially wider spacers that are to be sequentially inserted into and removed from an intervertebral space to widen the space until a desired anatomical spacing of the adjacent vertebral bones is restored. The set of spacers includes a porous spacer that is as wide as the spacer that restores the desired anatomical spacing. The porous spacer can therefore be left implanted in the intervertebral space to promote fusion of the adjacent vertebral bones.
1. An intervertebral spacer, comprising:
a spacer body having a porous surface and a beveled edge extending around a spacer body circumference, the spacer body having
a circular upper portion including
an upper surface with a center that is substantially flat and a central bore formed through at least a portion of the center and extending through the spacer body
a first diameter; and
a first angle designation mark extending through the upper portion forming a first reduced diameter of the upper portion in the same plane as the first diameter,
a circular lower portion including
a lower surface, the upper and lower surfaces being displaced from each other a maximum distance along a first axis; and
a second diameter, and
a central trunk separating the upper and lower portions, the central trunk having a third diameter smaller than the first and second diameters,
wherein the first reduced diameter is greater than the third diameter.
2. The intervertebral spacer of claim 1 , wherein the upper and lower surfaces are diametrically tapered.
3. The intervertebral spacer of claim 1 , wherein the upper and lower relative angle designation marks are grooves.
4. The intervertebral spacer of claim 1 , wherein the lower portion further includes a third maximum dimension and a second angle designation mark forming a second reduced dimension, and the second reduced dimension is greater than the second maximum dimension.
5. The intervertebral spacer of claim 4 , wherein the first, second and third maximum dimensions are diameters.
6. An intervertebral spacer, comprising:
a spacer body having a porous surface, a beveled edge extending around a spacer body circumference, and an annular groove, the spacer body having:
a central trunk having a first diameter,
a circular upper surface having a second diameter,
a circular lower surface having a third diameter, the upper and lower surfaces being displaced from each other a maximum distance along a first axis by the central trunk,
a central bore formed through the upper and lower surfaces, at least one of the upper and lower surfaces having a center that is substantially flat, the central bore formed through at least a portion of the center,
at least one relative angle designation mark extending through the upper surface forming a first reduced diameter of the upper surface in the same plane as the second diameter and
at least one relative angle designation mark extending through the lower surface forming a second reduced diameter of the lower surface in the same plane as the third diameter,
wherein the first and second reduced dimensions are greater than the first diameter.
7. The intervertebral spacer of claim 6 , wherein the annular groove is tapered.
8. The intervertebral spacer of claim 6 , wherein the upper and lower surfaces of the spacer body are diametrically tapered.
9. The intervertebral spacer of claim 6 , wherein the relative angle designation marks extend from a wall of the annular groove to either the upper or lower surface.
10. The intervertebral spacer of claim 6 , wherein the spacer body further includes an upper radial flange disposed between the upper surface and the axially medial groove and a lower radial flange disposed between the lower surface and the annular groove.
11. The intervertebral spacer of claim 6 , wherein the upper and lower relative angle designation marks are grooves.
12. An intervertebral implant, comprising:
a spacer body having a beveled edge extending around a spacer body circumference and an annular groove, the spacer body having:
a central trunk having a maximum first diameter,
a circular upper surface having a second diameter,
a circular lower surface having a third diameter, the upper and lower surfaces being displaced from each other a maximum distance along a first axis by the central trunk,
a central bore formed through the upper and lower surfaces, at least one of the upper and lower surfaces having a center that is substantially flat, the central bore formed through at least a portion of the center,
at least one relative angle designation mark extending through the upper surface forming a first reduced diameter of the upper surface in the same plane as the second diameter,
at least one relative angle designation mark extending through the lower surface forming a second reduced diameter of the lower surface in the same plane as the third diameter,
an upper radial flange disposed between the upper surface and the annular groove and
a lower radial flange disposed between the lower surface and the annular groove,
wherein the first and second reduced dimensions are greater than the first diameter.
13. The intervertebral implant of claim 12 , wherein the upper and lower surfaces of the spacer body are diametrically tapered.
14. The intervertebral implant of claim 12 , wherein the annular groove is tapered.
15. The intervertebral spacer of claim 12 , wherein the relative angle designation marks extend from a wall of the annular groove to either the upper or lower surface.
16. The intervertebral spacer of claim 12 , wherein the upper and lower relative angle designation marks are grooves.
17. An system comprising:
a spacer having a porous surface and a beveled edge extending around a spacer circumference, the spacer having:
a circular upper portion including an upper surface with a center that is substantially flat, a central bore formed through at least a portion of the center and extending through the spacer body, a first diameter extending through the upper portion forming a first reduced diameter of the upper portion in the same plane as the first diameter,
a lower portion including a lower surface and a lower relative angle designation mark, and
a central trunk separating the upper and lower portions by a maximum distance along a first axis, the central trunk having a second diameter, the second diameter being smaller than the first diameter,
wherein the first reduced diameter is greater than the second diameter; and
an insertion tool coupled to the central trunk of the spacer so that the upper and lower relative angle designation marks are simultaneously visible while the spacer is attached to an insertion tool during insertion.