A pivotal bone anchor system includes a plurality of bone anchors having rounded capture portions with circumferentially extending capture recesses. The system also includes multi-planar receiver sub-assemblies, each comprising a multi-planar receiver defining a cavity with a multi-planar seating surface, and a multi-planar pivoting retainer configured for multi-planar motion upon engagement with the multi-planar seating surface and to snap into a capture recess to capture a bone anchor within the multi-planar receiver. The system further includes uni-planar receiver sub-assemblies, each comprising a uni-planar receiver defining a cavity with a uni-planar seating surface, and a uni-planar pivoting retainer configured for uni-planar motion upon engagement with the uni-planar seating surface and to snap into a capture recess to capture a bone anchor within the uni-planar receiver. The capture portions of the bone anchors are configured for capture by either a multi-planar or uni-planar receiver sub-assembly without further modification or adjustment.

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.

A system and methods for assembling an expandable vertebral implant for engagement between vertebrae. The implant may expand and/or collapse between a variety of lengths. The implant may include an inner core, an outer core, and/or a middle core such that the inner and outer cores may be moveable relative to each other along an axis. The middle core may include one or more gear teeth. The implant may include one or more locking mechanisms. The implant may include one or more endplates. One endplate may be fixed and/or polyaxial. A tool may be used to vary the length of the implant.

A receiver of a bone anchor includes a base and a pair of upright arms extending upward from the base to define an open channel for receiving an elongate rod, with the upright arms having opposed interior surfaces with a discontinuous guide and advancement structure formed therein and side outer faces opposite the opposed interior surfaces extending downward across the base to a bottom of the receiver. A horizontally-elongated upper tool engaging groove is formed into the side outer face of each upright arm that extends to at least a front face or back face of the upright arm and that includes a downwardly-facing upper surface, an upwardly-facing lower surface, and an outwardly-facing inner surface. A vertical tool-engaging groove is also formed into the side outer face of each upright arm that extends downward from a top surface of the upright arm through to a level below the lower surface of the upper tool engaging groove.

A pivotal bone anchor assembly includes a bone anchor having a capture portion with a frusto-conical outer surface and a horizontal capture recess extending circumferentially around a mid-portion thereof, a receiver having a central bore with a seating surface proximate a bottom opening, and a ring retainer having a retainer aperture with an inner surface that is slidably engageable with the frusto-conical outer surface of the capture structure and a retainer aperture recess extending circumferentially into the inner surface. The assembly further includes a snap ring positionable within the retainer aperture recess with a snap ring aperture smaller than the retainer aperture. Upon securing the ring retainer within the central bore with the retainer aperture centered above the bottom opening, the capture portion is uploadable into the retainer aperture with the frusto-conical outer surface engaging and continuously expanding the snap ring until the horizontal capture recess reaches the retainer aperture recess and the snap ring snaps into the horizontal capture recess to couple the bone anchor to the ring retainer.

Various methods and apparatus for dynamic stabilization of bones, and especially of vertebra. Disclosed herein are bushings that permit axial movement of a rod, tether, or similar interconnection device relative to an anchoring head that is coupled to a bone. Some bushings further allow lateral relative movement or rotational relative movement, such additional relative movement being limited by the size and shape of the bushing, the size and shape of the interconnection device, the size and shape of the bushing container, the manner of attaching the anchoring head to the bone, or other considerations.

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 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 system includes a plurality of bone anchors with rounded capture portions having a circumferentially extending outer engagement surface without flat side faces. The system also includes multi-planar receiver sub-assemblies, each comprising a multi-planar receiver defining a cavity with a multi-planar seating surface, and a multi-planar pivoting retainer configured for multi-planar motion upon engagement with both the multi-planar seating surface and the outer engagement surface of a bone anchor. The system further includes uni-planar receiver sub-assemblies, each comprising a uni-planar receiver defining a cavity with a uni-planar seating surface, and a uni-planar pivoting retainer configured for uni-planar motion upon engagement with the uni-planar seating surface and the outer engagement surface of another bone anchor. The capture portions of the bone anchors are configured for capture by either a multi-planar or uni-planar receiver sub-assembly without further modification or adjustment.

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.