Patent ID: 7815665

Claim:
A multiple phase connection unit for use in flexibly stabilizing a first vertebra to a second vertebra, the connection unit comprising: a first bone coupling assembly having a U-shaped channel; a second bone coupling assembly having a U-shaped channel; and a longitudinal member having a central axis, the longitudinal member including a first end received within the U-shaped channel of the first bone coupling assembly, a second end received within the U-shaped channel of the second bone coupling assembly and a flexible section in between the first and second ends, the flexible section including an inner cavity; and a tether located in the inner cavity formed in the flexible section of the longitudinal member, the tether coupled to the first and second ends, the longitudinal member being bendable from an original position to a second position when subjected to an externally applied bending force (f), the longitudinal member being displaced by a distance d in the second position, the tether being in a slack position when the longitudinal member is in the original position and in a taut position when the longitudinal member is displaced by a first taut distance dt via the externally applied bending force (f) such that the tether resists further displacement of the longitudinal member away from the original position, the first taut distance dt being greater than zero and less than the distance d in the second position.