Vertebral body replacement
The present invention involves a system and methods for assembling and implanting a vertebral body implant. The vertebral body implant includes, but is not necessarily limited to, an expandable core body and endplates that can be attached at both ends. Endplates of various shapes, sizes and angles are attachable to the expandable core in a plurality of positions so that a suitable vertebral body implant can be implanted between vertebrae from an anterior, anterior-lateral, lateral, posterior or posterior-lateral approach.
1. An implant for providing support between a first vertebra and a second vertebra in a space remaining after the removal of at least part of one vertebra, comprising:
an expandable body having an outermost surface, an inner core with a helical exterior thread, a transverse axis and a longitudinal axis, and a length extending along the longitudinal axis from a first end to a second end, the expandable body including a ring member with an external surface co-planar with the outermost surface of the expandable body, rotatable about the longitudinal axis of the expandable body to adjust the length between the first end and the second end, a first endplate attachment feature at the first end, and a second endplate attachment feature at the second end;
a first endplate having a first surface and an opposing second surface, said first endplate coupled to the expandable body via a first complementary attachment feature, on the first surface that mates with the first endplate attachment feature of the first end of the expandable body,
a second endplate having a first surface and an opposing second surface, said second endplate coupled to the expandable body via a second complementary attachment feature on the first surface that mates with the second endplate attachment feature of the second end of the expandable body;
wherein said first endplate and said second endplate are freely and independently rotatable relative to the longitudinal axis;
wherein said first endplate attachment feature and said second endplate attachment feature each comprise a ring of threaded holes defining a perimeter, said perimeter generally sinusoidal or flower-shaped and encircling a central aperture; and
wherein said first endplate attachment feature is integrally formed on a first end of the inner core.
2. The implant of claim 1 , wherein said second surface of said first endplate and said second surface of said second endplate are convexly curved.
3. The implant of claim 1 , wherein said first surface of the first endplate and said second surface of the first endplate are parallel to each other.
4. The implant of claim 1 , wherein said first surface of said first endplate and said second surface of said first endplate form an angle relative to each other.
5. The implant of claim 3 , wherein said first surface of the second endplate and said second surface of the second endplate are parallel to each other.
6. The implant of claim 3 , wherein said first surface of the second endplate and said second surface of the second endplate form an angle relative to each other.
7. The implant of claim 4 , wherein said first surface of the second endplate and said second surface of the second endplate form an angle relative to each other.
8. The implant of claim 4 , wherein the angle ranges from −4° to 7°.
9. The implant of claim 1 , wherein said first endplate and said second endplate have a length dimension greater than a width dimension.
10. The implant of claim 1 , wherein said first endplate and said second endplate are circular.
11. The implant of claim 9 , wherein said first endplate and said second endplate are dimensioned to span from one lateral aspect of a vertebral body endplate to another lateral aspect of the vertebral body endplate.
12. The implant of claim 1 , wherein said expandable body further comprises an outer core, wherein said ring member is coupled to the inner core and the outer core such that rotation of the ring member causes the inner core to translate relative to the outer core and increases the length between said first end and said second end of the expandable body.
13. The implant of claim 1 , wherein said expandable body and said first and second endplates include a fusion aperture extending therethrough.
14. The implant of claim 6 , wherein the angle ranges from −4° to 7°.
15. The implant of claim 7 , wherein the angle ranges from −4° to 7°.
16. The implant of claim 9 , wherein the length is 60 mm.
17. The implant of claim 16 , wherein the width is 22 mm.
18. The implant of claim 9 , wherein the length is 60 mm.
19. The implant of claim 16 , wherein the width is 22 mm.
20. The implant of claim 1 , wherein each of first and second endplate attachment features comprises a ring of twelve threaded holes.