Patent ID: 8048120

Claim:
An implantable modular device for stabilizing relative motion of spinal vertebrae, comprising: a first pair of plates attachable to a first spinous process; a second pair of plates attachable to a second spinous process; a first spacing member positionable to fit between the first and second spinous processes to provide a selected level of stiffness between the spinous processes, the first spacing member comprising a first bearing surface and a second bearing surface orthogonal to the first bearing surface, the first bearing surface positionable to contact an inferior surface of the first spinous process and a superior surface of the second spinous process, the second bearing surface shaped as a continuous annulus, the second bearing surface positionable to directly contact a lateral surface of the first spinous process and an ipsilateral surface of the second spinous process; and a fastener joining the first spacing member and the first and second pairs of plates, the fastener comprising a head and a shaft, the shaft having a first end and a second end and a longitudinal axis extending therebetween, the shaft first end passing freely through the first pair of plates and the spacing member and then directly engaging an outermost one of the second pair of plates to join the first pair of plates, the second pair of plates and the spacing member together along the longitudinal axis of the fastener shaft between the head and the shaft first end, wherein the first and second pairs of plates are rotatably attachable together at any of a variety of relative orientations in response to securement of the fastener to the first and second pairs of plates to permit further relative rotation between the pairs of plates, thereby permitting dynamic relative motion between the first and second spinous processes.