Patent ID: 9597195
Date: 2017-03-21
CPC Classifications: A61F

Claim:
1. An expandable intervertebral implant insertable into an intervertebral disc space disposed between a lower vertebra and an upper vertebra, the expandable intervertebral implant comprising: a rear end that defines a guide surface for insertion into the intervertebral disc space, and a front end opposite the rear end, wherein the front and rear ends are spaced from each other along a longitudinal axis, such that the front end is spaced away from the rear end along the longitudinal axis; an outer sleeve including an upper sleeve portion that defines an upper vertebral engagement surface configured to abut the upper vertebra when the implant is disposed in the intervertebral disc space, the outer sleeve further including a lower sleeve portion that defines a lower vertebral engagement surface that is spaced from the upper vertebral engagement surface and is configured to abut the lower vertebra when the implant is disposed in the intervertebral disc space, wherein 1) the upper sleeve portion defines respective first and second engagement surfaces, and 2) the outer sleeve defines an internal void at a location between the upper vertebral engagement surface and the lower vertebral engagement surface; and an inner core including respective first and second core engagement surfaces, one of the first and second core engagement surfaces spaced in its entirety from the other of the first and second core engagement surfaces in a direction away from the rear end along the longitudinal axis, the first and second core engagement surfaces configured to engage the first and second engagement surfaces, respectively, of the upper sleeve portion, such that translation of the inner core in the direction away from the rear end along the longitudinal axis in the internal void causes the first and second core engagement surfaces of the inner core to move together along the first and second engagement surfaces of the upper sleeve portion in the direction away from the rear end along the longitudinal axis, thereby causing the first and second engagement surfaces of the upper sleeve portion to ride along respective ones of the first and second core engagement surfaces of the inner core, which in turn urges an entirety of the upper sleeve portion to move away from an entirety of the lower sleeve portion along a transverse direction that is perpendicular to the longitudinal axis so as expand the implant from an initial position to an expanded position, whereby 1) in the initial position, the upper and lower vertebral engagement surfaces are spaced from each other a first distance, and 2) in the expanded position, a) the upper and lower vertebral engagement surfaces are spaced from each other a second distance greater than the first distance, and b) the first and second core engagement surfaces of the inner core remain in contact with the first and second engagement surfaces of the upper sleeve portion, wherein when the implant is in the expanded position, the implant is configured to prevent the upper and lower sleeve portions from moving toward each other so as to decrease the second distance, and wherein the first and second core engagement surfaces of the inner core are each sloped in the direction away from the rear end along the longitudinal axis as they extend away from the upper vertebral engagement surface, and the first and second engagement surfaces of the upper sleeve portion are each sloped in the direction away from the rear end along the longitudinal axis as they extend away from the upper vertebral engagement surface.