A fixation assembly includes a pedicle screw having a screw head, an elongate tulip head inserted over the pedicle screw, and a swivel rocker inserted into the tulip head. The swivel rocker has an axial through passage extending therethrough, an arcuate concave distal face being contoured to match the screw head, and a saddle shaped proximal face. A rod assembly is seated on the saddle shaped proximal face. A retainer ring secures the tulip head around the screw head. A method of implanting the assembly is also provided.

A dynamic longitudinal connecting member assembly includes an anchor member having an integral or otherwise fixed elongate core of circular or non-circular cross-section. The core is pre-tensioned and extends through at least one elastic spacer and at least one outer sleeve. The anchor member and the outer sleeve each attach to at least one bone anchor. In operation, the core is held in tension by the spacer.

A dynamic longitudinal connecting member assembly includes an anchor member having an integral or otherwise fixed elongate core of circular or non-circular cross-section. The core is pre-tensioned and extends through at least one elastic spacer and at least one outer sleeve. The anchor member and the outer sleeve each attach to at least one bone anchor. In operation, the core is held in tension by the spacer.

A dynamic fixation medical implant having at least two bone anchors includes a longitudinal connecting member assembly having at least one transition portion and cooperating outer sleeve, both the transition portion and sleeve being disposed between the two bone anchors. In a first embodiment, the transition portion includes a rigid length or rod having apertures therein for tying or otherwise attaching the rigid length to a second rigid length or to a flexible cord. Slender ties or cords extend through a plurality of apertures in the rigid lengths or are threaded, tied or plaited to the larger flexible cord or cable. In a second embodiment, a transition portion includes slender ties of a cord that are imbedded in a molded plastic of a more rigid member. The outer sleeve may include compression grooves. The sleeve surrounds the transition portion and extends between the pair of bone anchors, the sleeve being compressible in a longitudinal direction between the bone anchors.

An adjustable spinal stabilization system for maintaining preselected spacing and movement between adjacent vertebrae in a spinal column and for providing overall stability thereto. The system includes at least one interlaminar member positioned in the spaces intermediate a first vertebra and the vertebrae positioned immediately above or immediately below and adjacent to the first vertebra. The interlaminar member is operatively connected to an adjustable support structure and cooperates therewith to maintain the preselected spacing between adjacent vertebrae and to provide overall stability to the spinal column.

A pivotal bone anchor assembly for securing an elongate rod to a bone of a patient. The assembly includes a receiver having pair of upright arms that define an open channel configured to receive the elongate rod and a discontinuous helically wound receiver guide and advancement structure formed into the interior surfaces of the upright arms. The assembly further includes a closure configured for positioning within the open channel to secure the elongate rod to the receiver in a locked configuration, with the closure having an outer surface with a mating continuous helically wound closure guide and advancement structure configured to resist a tendency toward splaying between the upright arms upon a screwing in of the closure within the open channel by rotatable engagement with the receiver guide and advancement structure.

A receiver assembly for securing an elongate rod to a bone anchor includes a receiver having pair of upright arms that define an open channel configured to receive the elongate rod, a discontinuous helically wound receiver guide and advancement structure formed into the interior surfaces of the upright arms, and horizontally-elongated tool engaging grooves formed into upper portions of the outer surface of the upright arms. The receiver assembly further includes a closure configured for positioning within the open channel to secure the elongate rod to the receiver in a locked configuration, with the closure having an outer surface with a mating continuous helically wound closure guide and advancement structure configured to resist a tendency toward splaying between the upright arms upon a screwing in of the closure within the open channel by rotatable engagement with the receiver guide and advancement structure.

A system and method for sharing and absorbing energy between body parts. In one particular aspect, the system facilitates absorbing energy between members forming a joint such as between articulating bones. In one embodiment, there is provided a system for manipulating energy transferred by members defining a joint, the members collectively defining a path of motion and having a cartilage having an energy absorption component configured therebetween.

One embodiment of the disclosure relates to a flexible bone fixation device including two first fixation parts and a first flexible spanning part, connected between the two first fixation parts. The first flexible spanning part has a plurality of first cuts spaced apart by one another.

Apparatus and method for dynamic connection between adjacent bones. Various embodiments pertain to a bone anchor that includes a rotatable spool, the spool being configured to place tension on a flexible member, such as a tether, suture, cable, or other. Still further embodiments pertain to tools for interconnecting two bone anchors with a tether.