A polyaxial bone anchor has a locking element shaped and configured to allow an anchoring member (e.g., a screw or hook) to polyaxially rotate at large angles about a central axis of the bone anchor before compression locking the anchoring member within an anchor head.

A pedicle screw implant construct kit, comprising at least one pedicle screw, at least one collar comprising a recess for receiving a rod, the collar configured to be coupled to a head of the pedicle screw, an elongated rod for connecting the collar to one more additional collars to couple between the pedicle screw and one or more additional screws, and a locking ring sized to be positioned over at least a distal portion of the collar to restrain relative movement of the screw head and rod by exerting radial compression force onto the collar. In some embodiments, the components of the kit are comprised of carbon reinforced composite material, optionally with no radiation blocking material. In some exemplary embodiments of the invention, the kit includes two locking rings on a collar, optionally both below the rod.

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. A first part is engageable with a spinal rod disposed with the implant cavity. A second part is attached with the first part and engageable with the second band to dispose the second band 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 spinal implant includes a first member having an inner surface defining an implant cavity and at least one mating element. A second member includes a head and a shaft configured to penetrate tissue. The head includes at least one mating element engageable with the at least one mating element of the first member and a part. A third member includes an inner surface engageable with the part such that the members comprise a bone fastener having a selected movement. Systems, instruments and methods are disclosed.

A bone fastener comprises a first member defining an implant cavity. A part is connectable with the first member. A second member is configured to penetrate tissue and includes a mating surface engageable with the part. The part is engageable to selectively translate the implant cavity relative to the second member. Implants, spinal constructs, systems, instruments and methods are disclosed.

A bone attachment assembly may include an attachment head, a set screw configured to attach to the attachment head, and a rod surface with a first raised portion and a second raised portion that define a lowered portion positioned between the first raised portion and the second raised portion. The first raised portion, the second raised portion, and the set screw may be configured to directly contact a rod in order to retain the rod within the attachment head.

A pivotal bone anchor assembly includes a shank sub-assembly comprising a shank and a coupler, and a receiver sub-assembly comprising a receiver having a bore with a bottom opening and a snap-fit assembly proximate the bottom opening comprising an insert, a retainer ring positioned within an expansion chamber, and a positioner configured to hold the retainer ring in position. The shank sub-assembly is uploaded through the receiver bottom opening such that the positioner is pushed up into a holder chamber and the retainer rings engages a circumferential locking groove of the coupler to secure the shank sub-assembly with the receiver sub-assembly with a snap-fit connection.

Devices and methods for enhancing the effectiveness of spinal stabilization, and particularly that of cervical spinal stabilization, are provided herein. More specifically, methods and systems are disclosed for effectively positioning occipital plates and spinal fixation assemblies within target vertebrae, while also reducing any associated patient trauma (e.g., muscle stripping, tissue damage, etc.). The systems and methods can utilize trans-lamina delivery of the spinal fixation assemblies to allow for the positioning of the fixation elements along the midline of the patient's spine.

A spinal screw assembly providing an adjustable securement of a fixation rod across at least two vertebrae. The assembly includes a pedicle screw having a spherical head portion, a threaded shaft portion and a tool engagement surface in the head portion for use in driving the screw into a vertebrae. The head portion of the screw is positioned in a body member adjacent a curvilinear surface disposed about an aperture in the end of the body member such that the shaft portion of the screw extends therethrough and the curvilinear inner surface abuts and mates with the head portion of the screw so as to define a ball joint therewith. The body member additionally defines a pair of opposed parallel slots therein adapted to receive a portion of the fixation rod and a locking cap bears against the fixation rod to releasably secure the rod within the assembly.