Expandable intervertebral implant

Patent metadata

Field	Value
Publication number	US-9492289-B2
Application number	US-201514688561-A
Country	US
Kind code	B2
Filing date	Apr 16, 2015
Priority date	Mar 15, 2013
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

An implant for therapeutically separating bones of a joint has two endplates each having an opening through the endplate, and at least one ramped surface on a side opposite a bone engaging side. A frame is slideably connected to the endplates to enable the endplates to move relative to each other at an angle with respect to the longitudinal axis of the implant, in sliding connection with the frame. An actuator screw is rotatably connected to the frame. A carriage forms an open area aligned with the openings in the endplates. The openings in the endplates pass through the carriage to form an unimpeded passage from bone to bone of the joint. The carriage has ramps which mate with the ramped surfaces of the endplates, wherein when the carriage is moved by rotation of the actuator screw, the endplates move closer or farther apart.

First claim

What is claimed is:

1. An implant for placement between bones, the implant defining a longitudinal axis extending between distal and proximal ends, the implant comprising:
a first endplate configured to engage a first bone, and having an opening through the endplate, and at least one ramped surface on a side opposite a bone engaging side;
a second endplate configured to engage a second bone, and having an opening through the endplate, and at least one ramped surface on a side opposite a bone engaging side;
a frame at least partially surrounding at least a portion of the first endplate;
a carriage having an open area at least partially aligned with the openings in the first and second endplates;
an actuator screw engaging the carriage; and
a blocking mechanism configured to prevent backing out of a fastener passed through at least one of the first and second endplates and into one of the first or second bones, the blocking mechanism including a blocking member moveably retained within a channel between an unblocking position and a blocking position in which a portion of the blocking member overlaps a portion of the fastener,
whereby rotation of the actuator screw moves the carriage with respect to the frame and the first and second endplates; and
wherein the carriage comprises a plurality of ramps each engageable with at least one of the at least one ramped surfaces of the first and second endplates, wherein when the carriage is moved by rotation of the actuator screw, at least one of the at least one ramped surface of the first endplate and at least one of the at least one ramped surface of the second endplate each move along at least one of the plurality of ramps of the carriage to cause the endplates to move relative to each other in connection with the frame,
wherein the implant has a length extending from the distal end to the proximal end of the implant and a width extending perpendicular to the length, the width of the implant is greater than the length of the implant.

2. The implant of claim 1 , the first and second endplates move relative to each other only along an axis substantially transverse to the longitudinal axis.

3. The implant of claim 1 , wherein at least one of the first and second endplates includes at least one aperture through which the fastener may pass to secure the implant to one of the first or second bones.

4. The implant of claim 1 , wherein the frame is metallic.

5. The implant of claim 1 , further including a polymeric material configured to press against the actuator screw to reduce a potential for unintended rotation of the actuator screw.

6. The implant of claim 1 , wherein when the actuator screw is rotated in a first direction, a height of the implant transverse to the longitudinal axis is increased, and when the actuator screw is rotated in a second direction, a height of the implant transverse to the longitudinal axis is decreased.

7. The implant of claim 1 , wherein the actuator screw is threadably connected to the carriage.

8. The implant of claim 1 , wherein the actuator screw is connected to the frame and threadably connected to the carriage.

9. The implant of claim 1 , wherein at least a portion of the first endplate is polymeric and at least a portion of the second endplate is polymeric.

10. The implant of claim 1 , wherein the frame extends from the distal end of the implant towards the proximal end of the implant.

11. The implant of claim 1 , further including at least one post extending through the frame and into the carriage, received in one of the frame or the carriage, thereby configured to maintain an alignment of the carriage along the longitudinal axis.

12. The implant of claim 1 , further including a first passage formed in at least one of the first and second endplates, and a second passage formed in the carriage, the first and second passages aligned to admit introduction of a therapeutic material into the open area of the carriage when the implant is implanted between bones.

13. The implant of claim 1 , wherein the frame connects to the first and second endplates with a dovetail connection.

14. The implant of claim 1 , wherein ends of the at least one of the plurality of ramps of the carriage slide within grooves in at least one of the first and second endplates.

15. The implant of claim 1 , wherein:
the frame includes an actuator screw bearing, a first tab extending away from the bearing in a first direction, and a second tab extending away from the bearing in a direction opposite to the upper tab, the first and second tabs forming edges; and the first and second endplates including grooves sized and dimensioned to slidingly receive the edges of the first and second tabs, respectively.

16. An implant comprising:
a first endplate configured to engage a first bone, and having an opening through the endplate transverse to the longitudinal axis, and at least one ramped surface on a side opposite a bone engaging side;
a second endplate configured to engage a second bone of the joint, and having an opening through the endplate transverse to the longitudinal axis, and at least one ramped surface on a side opposite a bone engaging side;
a carriage having an open area aligned with the openings in the first and second endplates;
a U-shaped frame partially surrounding the carriage; and
an actuator screw rotatably connected to the carriage,
whereby rotation of the actuator screw moves the carriage with respect to the frame and the first and second endplates;
wherein the carriage comprises a plurality of ramps engageable with at least one of the at least one ramped surfaces of the first and second endplates, wherein when the carriage is moved by rotation of the actuator screw, at least one of the at least one ramped surface of the first endplate and at least one of the at least one ramped surface of the second endplate each translate along at least one of the ramps of the carriage to cause the endplates to move relative to each other; and
wherein the implant has a length and a width extending perpendicular to the length, the width of the implant is greater than the length of the implant.

17. The implant of claim 16 , at least one passage formed in the carriage in communication with at least one passage in at least one of the first or second endplates, the communicating passages configured to admit introduction of a therapeutic material into the open area of the carriage when the implant is implanted between bones.

18. The implant of claim 16 , wherein the first endplate includes a polymeric portion and a metallic portion and the second endplate includes a polymeric portion and a metallic portion.

19. The implant of claim 16 , wherein the U-shaped frame includes an extended region with an extension guide configured to engage one or both of the first and second endplates.

20. The implant of claim 16 , wherein a pin is affixed to the carriage and is slidable within a bore in the U-shaped frame to stabilize movement of the carriage when the actuator screw is rotated.

Assignees

• Globus Medical Inc

Inventors

• Davenport Daniel
• Sibson Duncan
• Iott Andrew
• Glerum Chad
• Gray Jason
• Silber Ben

Classifications

• A61F2002/30593

  hollow · CPC title

• A61F2/442

  Intervertebral or spinal discs, e.g. resilient (non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455) · CPC title

• A61F2002/30281

  wedge-shaped · CPC title

• A61F2002/30556

  for adjusting thickness · CPC title

• A61F2002/30387

  Dovetail connection · CPC title