Expandable intervertebral implant

Patent metadata

Field	Value
Publication number	US-9931223-B2
Application number	US-201615235160-A
Country	US
Kind code	B2
Filing date	Aug 12, 2016
Priority date	Apr 5, 2008
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

An expandable intervertebral implant is provided for insertion into an intervertebral space defined by adjacent vertebrae. The expandable intervertebral implant includes a pair of outer sleeve portions and an inner core disposed between the outer sleeve portions. Movement of the inner core relative to the outer sleeve portions causes the outers sleeve portions to deflect away from each other, thereby engaging the expandable intervertebral implant with the vertebrae and adjusting the height of the intervertebral space.

First claim

What is claimed:

1. An expandable intervertebral implant that is insertable into an intervertebral disc space and expandable from an initial position to an expanded position, the expandable intervertebral implant comprising:
a first outer portion defining opposed ends spaced from each other along a longitudinal direction that includes a first direction and a second direction opposite the first direction, the first outer portion further defining a first bone contacting surface, wherein the first outer portion further defines first and second sloped engagement surfaces that are spaced from each other along the longitudinal direction;
a second outer portion defining opposed ends spaced from each other along the longitudinal direction, the second outer portion further defining a second bone contacting surface spaced from the first bone contacting surface along a transverse direction that is substantially perpendicular to the longitudinal direction; and
an inner core disposed between the first and second outer portions with respect to the transverse direction, the inner core defining third and fourth sloped engagement surfaces that are spaced from each other along the longitudinal direction and aligned with each other along the longitudinal direction,
wherein (i) translation of the inner core in the first direction relative to the first and second outer portions causes the third and fourth sloped engagement surfaces to translate with each other in the first direction and ride along the first and second sloped engagement surfaces, respectively, in the first direction, thereby causing the first outer portion to deflect away from the second outer portion along the transverse direction from the initial position to the expanded position, (ii) the first and second bone contacting surfaces define a relative orientation with respect to each other that remains constant when the implant is in the initial position, during deflection of the first outer portion away from the second outer portion along the transverse direction, and when the expandable intervertebral implant is in the expanded position, (iii) the implant defines a height from the first bone contacting surface to the second bone contacting surface along the transverse direction, and the expandable intervertebral implant is configured such that when the expandable intervertebral implant is in the initial position, the height is at a minimum such that the implant is unable to achieve a height less than the minimum in response to movement of the inner core relative to the first and second outer portions along the longitudinal direction, and (iv) when the expandable intervertebral implant is in the expanded position, the first and second outer portions are prevented from moving toward each other in a direction from the expanded position toward the initial position in response to a compressive force applied to the first and second bone outer portions along the transverse direction while (a) the first sloped engagement surface is in abutment with the third sloped engagement surface and (b) the second sloped engagement surface is in abutment with the fourth sloped engagement surface.

2. The expandable intervertebral implant of claim 1 , wherein each of the first and second outer portions is movable along the transverse direction with respect to the other of the first and second outer portions as the expandable intervertebral implant expands from the initial position to the expanded position.

3. The expandable intervertebral implant of claim 1 , wherein each of the first and second outer portions further defines respective first and second sloped engagement surfaces that are spaced from each other along the longitudinal direction, and the inner core includes first and second pairs of third and fourth sloped engagement surfaces, such that (i) the third and fourth sloped engagement surfaces of the first pair are configured to ride along the first and second sloped engagement surfaces, respectively, of the first outer portion as the inner core translates in the first direction relative to the first and second outer portions, and (ii) the third and fourth sloped engagement surfaces of the second pair are configured to ride along the first and second sloped engagement surfaces, respectively, of the second outer portion as the inner core translates in the first direction relative to the first and second outer portions.

4. The expandable intervertebral implant of claim 3 , wherein (i) translation of the inner core in the first direction relative to the first and second outer portions causes a) the third and fourth sloped engagement surfaces of the first pair to translate with each other in the first direction and ride along the first and second sloped engagement surfaces, respectively, of the first outer portion in the first direction, and b) the third and fourth sloped engagement surfaces of the second pair to translate with each other in the first direction and ride along the first and second sloped engagement surfaces, respectively, of the second outer portion in the first direction, thereby causing the first and second outer portions to deflect away from each other along the transverse direction from the initial position to the expanded position, and (ii) when the expandable intervertebral implant is in the expanded position, the first and second outer portions are prevented from moving toward each other in a direction from the expanded position toward the initial position in response to a compressive force applied to the first and second bone outer portions along the transverse direction while (a) the first engagement surface is in abutment with the third sloped engagement surface and (b) the second sloped engagement surface is in abutment with the fourth sloped engagement surface.

5. The expandable intervertebral implant of claim 4 , wherein a) the first and second sloped engagement surfaces of the first outer portion and the third and fourth sloped engagement surfaces of the first pair are sloped with respect to the longitudinal direction and are substantially parallel to each other, and b) the first and second sloped engagement surfaces of the second outer portion and the third and fourth sloped engagement surfaces of the second pair are sloped with respect to the longitudinal direction and are substantially parallel to each other.

6. The expandable intervertebral implant of claim 5 , further comprising a first member configured to abut the inner core and apply a biasing force to the inner core that drives the inner core to translate in the first direction relative the first and second outer portions.

7. The expandable intervertebral implant of claim 6 , wherein the inner core defines a bore that is elongate along the longitudinal direction, and the expandable intervertebral implant further comprises an elongate member that extends from the first member and is received in the bore, and is configured to apply the biasing force to the first member in the first direction that drives the inner core to translate relative to the first and second outer portions in the first direction.

8. The expandable intervertebral implant of claim 7 , wherein the elongate member is received in the bore at a first longitudinal end of the inner core, and extends away from the inner core at a second longitudinal end of the inner core that is opposite the first longitudinal end along the longitudinal direction.

9. The expandable intervertebral implant of claim 8 , wherein the elongate member defines a portion that is aligned with each of the first and second outer portions along the transverse direction prior to translation of the inner core in the first direction, and the portion of the elongate member is offset from the first and second outer p

Assignees

• Depuy Synthes Products Inc

Inventors

• Cain Christopher Marden John

Classifications

• A61F2002/3055

  for adjusting length · CPC title

• A61F2250/0006

  for adjusting angular orientation · CPC title

• A61F2002/3052

  unrestrained in only one direction, e.g. moving unidirectionally · CPC title

• A61F2220/0091

  connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type · CPC title

• A61F2002/30579

  with mechanically expandable devices, e.g. fixation devices · CPC title