System and method for facet joint replacement

摘要

A system for replacing at least a portion of a natural facet joint includes a fixation member implantable in a vertebra, an inferior facet articular surface and an inferior strut which may be formed separately from the inferior articular surface. The inferior strut has a first end securable to the fixation member and a second end which may comprise a sphere with a hemispherical surface. An attachment mechanism may include a capture feature shaped to receive the second end of the inferior strut, and the mechanism may provide an adjustable configuration, allowing polyaxial adjustment between the inferior articular surface and the second end. A locking member may be actuated to exert force on the second end to provide a locked configuration. The system may further include a superior facet joint implant with a superior articular surface shaped to articulate with the inferior articular surface.

主权项

1. An implantable system comprising:
an inferior facet implant having an articulatable body comprising a spherical member; a tulip body for receiving the articulatable body, wherein the spherical member of the articulatable body is capable of polyaxial rotation within the tulip body, wherein the articulatable body comprises an articulation surface spaced apart and separate from the spherical member, wherein the articulation surface comprises a bottommost surface of the inferior facet implant, wherein the articulation surface of the inferior facet implant is aligned with a corresponding uppermost articulation surface of a superior facet implant; a compressible member received in the tulip body, wherein the compressible member includes a trough that extends across an upper surface of the compressible member; a cross-link in the form of a longitudinally split cylinder, the cross-link being sized and shaped to be received in the trough of the compressible member; and a set screw received within the tulip body.