Adjustable intervertebral implant

摘要

An expandable intervertebral implant (10) includes a first member (20), a second member (40), and a collar operatively associated with the first and second members, wherein the collar includes a threaded mechanism so that rotation of the collar causes the second member to axially move with respect to the first member. The implant includes a ratchet mechanism (50, 80) so that when at least a predetermined amount of force is applied, the second member moves with respect to the first member in an axial, ratchet-type manner. The collar preferably includes a drive ring (60) rotatably attached to the first member and a ratchet ring (80) operatively associated with the drive ring. The ratchet ring includes an inner bore having at least one corresponding ratchet thread tooth form formed thereon for engaging a ratchet thread tooth form formed on the second member.

主权项

1. An expandable intervertebral implant that is configured to be disposed between first and second vertebrae, the expandable intervertebral implant comprising:
a first body member defining an axis, a first end, and a second end spaced from the first end of the first body member along the axis in an axial direction; a second body member having a first end and a second end, the second end of the second body member spaced from the first end of the second body member along the axial direction, the first end of the first body member positioned proximate the first end of the second body member in a collapsed position, the second body member including a ratchet portion comprising at least one first ratchet thread tooth form formed thereon; a ratchet ring carried by the first body member, the ratchet ring defining an inner bore that extends along the axis in the axial direction, and at least one slot configured to allow radial movement of the ratchet ring in a radial direction outwardly away from the axis, the ratchet ring having at least one second ratchet thread tooth form formed around the inner bore of the ratchet ring, the at least one second ratchet thread tooth form threadedly mated with the at least one first ratchet thread tooth form such that rotation of the ratchet ring causes the second body member to move in the axial direction with respect to the first body member while the first body member remains stationary in the axial direction relative to the ratchet ring, and an application of an axial force between the ratchet ring and the second body member causes the at least one first ratchet thread form to slide axially over the at least one second ratchet thread tooth form so that the second body member moves in the axial direction relative to the first body member; and a drive ring coupled to the ratchet ring such that rotation of the drive ring causes rotation of the ratchet ring, the drive ring defines a drive inner bore that receives at least a portion of the ratchet ring, wherein the drive ring includes a plurality of projections configured to mate with a circumferential groove formed on an outer surface of the first body member proximate the first end of the first body member.