A pivotal bone anchor assembly includes a shank having an anchor portion and a head with a partially spherical outer surface, a drive socket, an annular planar top surface surrounding the drive socket, and a frusto-conical surface between the planar top surface and the partially spherical outer surface. The assembly further includes a receiver having a base defining an axial bore and an upper portion defining a channel configured to receive a rod, and an insert positionable within the axial bore having an upper surface engageable with the rod, a lower surface for transferring a downwardly-directed force toward the head, and a central aperture for accessing the drive socket, with the rod extending across the central aperture when the fixation rod is engaged by the upper surface. After the head, the insert, and the rod are positioned in the receiver, the frusto-conical surface remains spaced apart from the rod to provide for increased articulation of the shank relative to the receiver.

A bone screw assembly includes an anchor portion and a head portion, such as a rod-receiving portion, movably mounted to the anchor portion to allow for controlled angulation between the anchor portion and the head portion. The anchor portion is pivotable in one or more selected directions about an axis relative to the head portion. A restriction member, which may be a rod seat, prevents the anchor portion from pivoting in one or more different directions about another axis relative to the head portion and/or a spinal fixation element received in the head portion. The restriction member may be inserted in the head portion to control direction that the anchor portion pivots relative to the head portion. The restriction member may also serve as a compression member and/or rod seat for seating a spinal rod coupled to the bone screw assembly.

A spinal fixation device includes a modular head assembly and a bone screw having a head and a shank. The modular head assembly includes a housing defining proximal and distal surfaces and a throughhole therethrough; an anvil slidable within the throughhole; a biasing member circumferentially surrounding the anvil; an assembly cap secured to the housing and defining an inner surface having a first portion with a first diameter and a second portion with a second diameter smaller than the first diameter; a retaining ring movable from the first portion of the assembly cap to the second portion of the assembly cap to transition the retaining ring between a first configuration in which the retaining ring is sized to receive the head of the bone screw and a second configuration in which the retaining ring is compressed about the bone screw to fix the bone screw relative to the modular head assembly.

A bone anchoring device for anchoring a rod to a bone or vertebra includes a receiving part with two legs defining a channel for the rod and a variable configuration member with a first rod contact surface configured to extend axially above a bottom of the channel to contact the rod. When a rod is inserted in the channel, the variable configuration member is adjustable from a first configuration where the first rod contact surface is at a first axial position relative to the receiving part and blocks the rod from contacting a second rod contact surface below the first rod contact surface, and a second configuration where the first rod contact surface is at a second axial position below the first axial position relative to the receiving part to permit the rod to contact the second rod contact surface.

A bone fastener comprises a first member defining an implant cavity and a plurality of adjacent grooves. A first band is configured for disposal within the grooves. A second band is configured for disposal within the grooves. A second member is configured to penetrate tissue and includes a head engageable with the first band to provisionally connect the members. The second band is moveable for disposal adjacent the first band to fix connection of the members. Implants, systems, instruments and methods are disclosed.

A fastener device includes an anchor body that defines a through hole. The anchor body further includes an inner surface that defines a least a portion of the through hole. The fastener includes a head, a threaded shaft that extends out with respect to the head in a distal direction, and a neck between the head and threaded shaft. The head includes an outer surface configured to articulate along the inner surface when the fastener head is inserted in the through hole. At least a portion of the outer surface is convex and defines a portion of a sphere that defines a first diameter. The neck defines a second diameter and the fastener defines a ratio of the first diameter to the second diameter in a range between about 2 to 1 and about 3 to 1.

A system for correcting a lateral curvature of a spine that can include a plurality of screws configured to be implanted in a plurality of vertebrae, and a plurality of extensions configured to be removably coupled with the plurality of screws. Some embodiments of the plurality of extensions can be curved, bent, angled, and/or offset along at least a portion thereof and can be removably coupled with a screw head of each of the plurality of screws. The system can include a connecting element or rod that is configured to be coupled with the plurality of screw heads. Some embodiments of the system can be configured such that the rod can be guided along the plurality of extensions from the proximal toward the distal end portions of the extensions and into engagement with the plurality of screws to cause the plurality of vertebrae to move laterally.

Systems, methods, and devices for securing a spinal rod are provided. A clamp assembly comprises a tulip comprising an opening comprising an inner surface, wherein the inner surface is threaded; and a threaded locking cap disposed in the opening, wherein threads of the locking cap and the inner surface include various geometries.

The present invention relates generally to medical devices and methods generally aimed at spinal surgery. In particular, the disclosed system and associated methods relate to performing spinal fixation with the use of a deformity system.

A polyaxial pedicle screw has a screw shaft and a screw head with a substantially spherical base shape. The polyaxial pedicle screw is mounted in a receiving sleeve or area. An insertion sleeve can be pressed against the screw head to determine a relative pivot position between the receiving sleeve or area and the screw shaft. Two pivot guide or pivot restriction units each have at least one extension projecting radially and in the longitudinal direction of the screw beyond the spherical base shape of the screw head. The extensions form stops on their radial outer surfaces and are positioned to permit relative pivoting of the screw shaft and the area or receiving sleeve only in one pivoting plane, and to abut in a supporting manner against a radially inner circumferential side of the area or receiving sleeve during relative pivoting in another pivoting plane.