Patent ID: 8308768

Claim:
A system for replacing at least a portion of a natural facet joint that controls motion between a first vertebra and a second vertebra, the system comprising: a first fixation member implantable in a pedicle of the second vertebra; and an inferior facet joint implant comprising: an inferior articular surface shaped to replace a natural inferior facet articular surface of the second vertebra; an inferior strut formed separately from the inferior articular surface, the inferior strut comprising a first end and a second end, wherein the first end is securable to the first fixation member and the second end comprises a sphere having an uninterrupted hemispherical surface; and an attachment mechanism comprising a capture feature shaped to receive the sphere, the attachment mechanism further comprising an adjustable configuration in which the inferior articular surface is connected to the second end in a manner that permits relative rotation between the inferior articular surface and the second end about three orthogonal axes, and a locked configuration in which the inferior articular surface is rigidly secured to the second end, wherein the capture feature for receiving the second end of the strut therein is formed monolithically with the inferior articular surface.