Expandable implant

Patent metadata

Field	Value
Publication number	US-9962270-B2
Application number	US-201615091058-A
Country	US
Kind code	B2
Filing date	Apr 5, 2016
Priority date	Aug 16, 2011
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

An expandable implant is disclosed in which the implant includes top and bottom plates having angled inner surfaces that interact with expansion members. The expansion members may be situated on an actuator, and may include at least one vertical projection. In some instances, rotation of the actuator in opposing directions about a longitudinal axis may cause the expansion members to move toward or away from one another, thereby resulting in separation of the top and bottom plates. During such expansion of the implant, the at least one vertical projection of the expansion members may be guided at least partially within a recess formed in the first or second plate. Pins may also be included with the expansion members that ride along respective slots in the plates during expansion. An insertion instrument for implanting the aforementioned implant, and methods of using the same, are also disclosed.

First claim

The invention claimed is:

1. An expandable intervertebral implant comprising:
top and bottom plates having inner and outer surfaces, the inner surfaces facing each other and each having a ramp surface and a recess disposed adjacent the ramp surface, each recess being formed in the respective top and bottom plate such that the top and bottom plates define a stop at a terminal portion of each recess;
an actuator situated between the inner surfaces of the top and bottom plates; and
first and second expansion members coupled to the actuator and located between the inner surfaces of the top and bottom plates, the first and second expansion members each having at least one vertical projection extending outwardly therefrom,
wherein rotation of the actuator in opposing directions causes the first and second expansion members to move toward and away from one another along a longitudinal axis of the actuator, resulting in movement of the top and bottom plates toward and away from one another along a vertical axis perpendicular to the longitudinal axis, the at least one vertical projection of the first and second expansion members being received and guided at least partially within one of the recesses adjacent the ramp surfaces of the top or bottom plates while such plates move along the vertical axis, and the at least one vertical projection of the first and second expansion members being adapted to translate within the recess relative to the actuator such that the at least one vertical projection of the first and second expansion members is adapted to move from a position spaced away from the respective stop to a position contacting the respective stop, where such contact between the at least one vertical projection and the respective stop prevents further movement of the first and second expansion members away from one another along the longitudinal axis of the actuator.

2. The expandable intervertebral implant of claim 1 , wherein the top and bottom plates each have apertures extending through the inner and outer surfaces thereof.

3. The expandable intervertebral implant of claim 2 , further including first and second post members, the post members being at least partially received within the apertures of the top and bottom plates.

4. The expandable intervertebral implant of claim 3 , further including first and second nuts, the first nut coupled to a distal end of the first post to secure the first post in one aperture of the top plate, and the second nut coupled to a distal end of the second post to secure the second post in another aperture of the top plate.

5. The expandable intervertebral implant of claim 1 , wherein the top and bottom plates each include a projection extending outwardly from an end of the respective top or bottom plate, the projection being located between the inner and outer surfaces of the plate.

6. The expandable intervertebral implant of claim 5 , wherein the actuator includes an engagement nut at an end thereof, the engagement nut being located between the projections of the top and bottom plates.

7. The expandable intervertebral implant of claim 6 , wherein the projections and engagement nut are adapted to be engaged by a distal end of an insertion instrument.

8. The expandable intervertebral implant of claim 1 , wherein the inner surface of at least one of the top and bottom plates has a first recessed portion for housing an intermediate portion of the actuator.

9. The expandable intervertebral implant of claim 8 , wherein the inner surface of the at least one of the top and bottom plates has a second recessed portion with a radius larger the first recessed portion for housing first and second opposed discs of the actuator.

10. The expandable intervertebral implant of claim 1 , wherein the first and second expansion members each include at least one lateral projection received within a corresponding lateral slot situated adjacent the ramp surface of each of the top and bottom plates.

11. The expandable intervertebral implant of claim 1 , wherein the actuator includes first and second threaded portions, the first and second threaded portions having oppositely facing threads configured to engage threads of the first and second expansion members, such that when the actuator is rotated, the first and second expansion members move along the longitudinal axis of the actuator in opposite directions.

12. The expandable intervertebral implant of claim 1 , wherein the vertical projections translate within the recess in a direction substantially parallel with the longitudinal axis of the actuator.

13. A method of implanting an expandable intervertebral implant comprising:
implanting an expandable intervertebral implant having top and bottom plates so that outer surfaces of the top and bottom plates engage first and second adjacent vertebral bodies of a spinal column of a patient;
rotating an actuator situated between inner surfaces of the top and bottom plates so that first and second expansion members coupled to the actuator move in a first direction, wherein the first and second expansion members each includes an angled surface that contacts the inner surface of the top or bottom plate and causes the top and bottom plates to move away from each other when the first and second expansion members move in the first direction; and
guiding a vertical projection of at least one of the first and second expansion members within an opening in the top or bottom plate; the guiding comprising translating the vertical projection within the opening relative to the actuator while the first and second expansion members move in the first direction, the opening being formed in the top or bottom plate such that the top or bottom plate defines a stop at a terminal portion of the opening, the stop adapted to interact with the vertical projection such that the stop prevents further movement of the first and second expansion members in the first direction.

14. The method of claim 13 , further comprising engaging a tool to the actuator and rotating the actuator with the tool.

15. The method of claim 14 , wherein the expandable implant includes a dovetail-shaped projection and the tool is engageable with the projection.

16. The method of claim 13 , wherein the first and second expansion members each has a pair of vertical projections extending therefrom.

17. The method of claim 13 , further comprising moving the first and second adjacent vertebral bodies away from each other while the first and second expansion members move in the first direction.

18. The method of claim 13 , further comprising guiding lateral projections within slots of the expandable implant.

19. The method of claim 13 , further comprising guiding a post member at least partially within a first set of apertures extending through the top and bottom plates.

Assignees

• Stryker European Holdings I Llc

Inventors

• Alheidt Thomas A
• Milz Bryan D
• Boljonis Dan
• Doreau Julien
• Herrmann Christine

Classifications

• A61F2002/30433

  using additional screws, bolts, dowels, rivets or washers e.g. connecting screws · CPC title

• A61F2002/3055

  for adjusting length · CPC title

• A61F2002/30405

  made by screwing complementary threads machined on the parts themselves · CPC title

• A61F2/4603

  for insertion or extraction of endoprosthetic joints or of accessories thereof · CPC title

• A61F2002/30594

  slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots · CPC title