Polyaxial pedicle screw with a head in the shape of a ball segment and with a threaded screw shank, wherein a hollow ball segment with a recess for receiving a rod-shaped connector is mounted in the head, in order to permit pivoting movements and rotation movements of the connector, wherein moreover, in the direction of the longitudinal axis of the threaded screw shank, the head in the shape of a ball segment has a cutout with an inner thread in which the rod-shaped connector can be moved in and out and, by means of the inner thread in the cutout, a grub screw can be introduced for blocking the hollow ball segment. According to the invention, a plastic buffer body is fitted in the hollow ball segment and is connected to a ram, wherein the ram has a head which engages in an associated annular groove in the plastic buffer body. Moreover, the plastic buffer body has a circumferential guide ring and a spherical guide stop at one end, wherein an opening for the ram is formed lying opposite the guide stop, and the edge of the opening bears on a shell, which in turn bears on the inner side of the hollow ball segment, in such a way that the plastic buffer body with its guide stop is fixed with pretensioning in the head shaped as a ball segment.

Methods and devices for treating spinal deformities are provided. In one exemplary embodiment, a low-profile spinal anchoring device is provided for receiving a spinal fixation element, such as a tether, therethrough. The device generally includes a staple body that is adapted to seat a spinal fixation element, a fastening element for fixing the staple body to bone, and a locking assembly for coupling a spinal fixation element to the staple body. In one embodiment, the locking assembly includes a washer that is adapted to couple to the staple body such that the spinal fixation is disposed therebetween, and a locking nut that is adapted to engage the staple body to mate the washer to the staple body.

A closed-head polyaxial screw for use in spinal instrumentation for spinal fusion, treatment of deformity, or the like. Polyaxial screws may have a two-part design, with the screw fitting into an aperture in the closed head. One or more clamps may secure the bone screw in the aperture. A closed-head polyaxial screw having a one part design is also disclosed. In addition, a one-part monaxial screw is described.

A polyaxial bone screw assembly includes a threaded shank body having an upper portion, a receiver member or head, a retaining and articulating structure, and a pressure insert disposed between the shank upper portion and a rod. The receiver has a U-shaped cradle defining a channel for receiving a spinal fixation rod and a receiver cavity. The retaining and articulating structure attaches to the shank and rotates with the shank in the cavity during positioning. The pressure insert presses upon the shank upper portion and not the retaining and articulating structure.

A polyaxial bone screw assembly includes a threaded shank body having an upper portion, a receiver member or head, a retaining and articulating structure, and a pressure insert disposed between the shank upper portion and a rod. The receiver has a U-shaped cradle defining a channel for receiving a spinal fixation rod and a receiver cavity. The retaining and articulating structure attaches to the shank and rotates with the shank in the cavity during positioning. The pressure insert presses upon the shank upper portion and not the retaining and articulating structure.

A polyaxial bone screw assembly includes a threaded shank body having an upper portion, a receiver member or head, a retaining and articulating structure, and a pressure insert disposed between the shank upper portion and a rod. The receiver has a U-shaped cradle defining a channel for receiving a spinal fixation rod and a receiver cavity. The retaining and articulating structure attaches to the shank and rotates with the shank in the cavity during positioning. The pressure insert presses upon the shank upper portion and not the retaining and articulating structure.

A closed-head polyaxial screw for use in spinal instrumentation for spinal fusion, treatment of deformity, or the like. Polyaxial screws may have a two-part design, with the screw fitting into an aperture in the closed head. One or more clamps may secure the bone screw in the aperture. A closed-head polyaxial screw having a one part design is also disclosed. In addition, a one-part monaxial screw is described.

Methods and devices for treating spinal deformities are provided. In one exemplary embodiment, a low-profile spinal anchoring device is provided for receiving a spinal fixation element, such as a tether, therethrough. The device generally includes a staple body that is adapted to seat a spinal fixation element, a fastening element for fixing the staple body to bone, and a locking assembly for coupling a spinal fixation element to the staple body. In one embodiment, the locking assembly includes a washer that is adapted to couple to the staple body such that the spinal fixation is disposed therebetween, and a locking nut that is adapted to engage the staple body to mate the washer to the staple body.

A double-headed pedicle screw is provided. The double-headed pedicle screw includes a threaded shaft portion and a plurality of yoke assemblies supported by the threaded shaft portion. Each of the yoke assemblies includes a recess configured to receive a portion of a rod, alignment structure, or immobilization structure therein. Each of the yoke assemblies is configured for pivoting movement relative to the threaded shaft portion independent of the pivoting movement of the other yoke assemblies.

A spinal stabilization system including an insert positionable in the channel of the housing of a vertebral anchor, and an associated support construct including a spacer and at least one cord extending through the insert. In some instances the construct includes first and second cords extending through first and second bores of the insert. A clamping member clamps the cord(s) in the insert. In some instances the clamping member includes first and second tabs movable in channels in first and second flanges of the insert.