Patent ID: 8585739

Claim:
A dynamic fixation member adapted for implantation in a patient by posterior attachment to a first vertebra of a spine of the patient using a first pedicle screw and a first connector, and to a second vertebra using a second pedicle screw and a second connector, to allow controlled bending of the first vertebra relative to the second vertebra, comprising: a first rod arm adapted for connection to the first pedicle screw by the first connector, and a second rod arm adapted for connection to the second pedicle screw by the second connector; and a deformable portion connected to the first and second rod arms, the deformable portion including a plurality of branch segments interconnected by a plurality of elastomeric hinges, wherein the plurality of branch segments include thinned portions adjacent the plurality of elastomeric hinges, and wherein the plurality of branch segments and the plurality of elastomeric hinges are configured around an opening; and wherein a first elastomeric hinge of the plurality of elastomeric hinges is situated adjacent the first rod arm, with a first branch segment and a second branch segment of the plurality of branch segments situated on either side of the first elastomeric hinge; wherein a first exterior side of the first branch segment is separated from the first rod arm by a first separation angle that is greater than a second separation angle located between a second exterior side of the second branch segment and the first rod arm; and wherein when implanted posteriorly in the patient, the deformable member allows controlled bending motion while limiting sagittal translation of the first vertebra relative to the second vertebra with lengthening and shortening of the deformable portion.