Patent ID: 7806911

Claim:
A fixation system for fixedly joining at least two spinous processes of a spinal column, the system comprising: a first elongated plate extending generally along a first longitudinal axis having a substantially planar medial bone facing surface and a substantially planar lateral facing surface disposed opposite the bone facing surface, a channel extending along a majority of a length of the bone facing surface, a bone growth promoting material disposed within the channel, and a retention member extending over the channel to retain the bone growth promoting material within the channel, at least one opening extending through the first elongated plate substantially transverse to the first longitudinal axis; a second elongated plate extending generally along a second longitudinal axis having a medial bone facing surface and a lateral facing surface disposed opposite the bone facing surface, a channel extending along a majority of a length of the bone facing surface, a bone growth promoting material disposed within the channel, and a retention member extending over the channel to retain the bone growth promoting material within the channel, at least one opening extending through the second elongated plate substantially transverse to the second longitudinal axis; and at least one fastener sized and shaped to extend through the at least one opening of the first elongated plate and through the at least one opening of the second elongated plate to connect the first elongated plate to the second elongated plate; wherein the channels of the first and second elongated plates are each defined by a planar inner surface extending substantially parallel to the substantially planar medial bone facing surface and an inner wall extending around the planar inner surface between the substantially planar medial bone facing surface and the planar inner surface, the inner wall having a generally cylindrical profile; wherein the bone facing surface of the first elongated plate includes a first plurality of bone-engaging protrusions surrounding the channel, the first plurality of bone engaging protrusions extending through the mesh retention member; wherein the bone facing surface of the second elongated plate includes a second plurality of bone-engaging protrusions surrounding the channel, the second plurality of bone engaging protrusions extending through the mesh retention member; wherein the first elongated plate has a first thickness between the medial bone facing surface and the lateral facing surface, and the channel of the first elongated plate has a first depth from the medial bone facing surface to the planar inner surface that is greater than 50% of the first thickness; and wherein the second elongated plate has a second thickness between the medial bone facing surface and the lateral facing surface, and the channel of the second elongated plate has a second depth from the medial bone facing surface to the planar inner surface that is greater than 50% of the second thickness.