Xerox Corporation

Nathaniel D Ginzton

Roger P Jackson

James L Surber

Jurell D Baker

A method of assembling a pivotal bone anchor assembly includes loading an insert into a central bore of a receiver, with the receiver having the central bore extending upward from a bottom opening to and through a first channel for receiving a rod, and the insert having an upper portion defining a second channel, opposite lateral protrusions extending outwardly in a direction transverse to the second channel, a lower collet portion, and a center opening. The method also includes positioning the insert into the central bore with the opposite lateral protrusions located adjacent to and above interference abutment surfaces formed into the central bore, and positioning a load ring within the center opening of the insert. The method further includes uploading a shank head into the central bore of the receiver through the bottom opening, capturing the shank head within the lower collet portion of the insert, and then forcibly downward displacing the insert within the central bore with the tooling so as to move the opposite lateral protrusions below the interference abutment surfaces.

Method of assembling a pivotal bone anchor assembly with a downwardly displaceable collet insert

A spinal fixation system includes a plurality of bone anchors, each having an anchor portion and a shank head with an upper spherical surface having a first diameter extending downward to an inner edge of an annular shelf spaced below a hemisphere plane, and a lower spherical surface having a second diameter greater than the first diameter extending downward from an outer edge of the annular shelf toward a neck extending between the shank head and anchor portion. The system also includes both pivoting and non-pivoting receiver sub-assemblies, with each receiver sub-assembly including a receiver having a central bore with a seating surface adjacent a bottom opening and a channel for receiving a rod. Each receiver sub-assembly also includes one of a multiplanar retaining structure, a monoplanar retaining structure, or a monoaxial retaining structure positioned therein and slidably engageable with the seating surface after capturing the shank head upon its uploading through the bottom opening.

Spinal fixation system with modular receiver sub-assemblies for connecting with bi-spherical universal shank heads

A bone anchor assembly includes a shank having a head and an anchor portion, and a receiver having a first channel to receive a rod and an axial bore with an upper internal thread, interference abutment surfaces below the upper internal thread, and a bottom opening. The assembly also includes an insert having a second channel to receive the rod and opposite lateral protrusions positioned above the interference abutment surfaces upon loading into a first position within the axial bore. The assembly further includes a resiliently expandable retainer positionable within the axial bore adjacent the bottom opening to capture and hold the head in the receiver. After the head is uploaded into the axial bore, the insert is downwardly deployable by tooling into a second position with the opposite lateral protrusions being forced below the interference abutment surfaces and with lower portions of the insert entering into compressive overlapping engagement with the retainer to hold down the retainer within the axial bore.

Bone anchor assembly having a tool deployable insert in compressive overlapping engagement with a retainer

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.

Pivotal bone anchor system with modular receiver sub-assemblies and universal bone anchors

A modular bone anchor system includes a plurality of bone anchors, with each bone anchor comprising a capture portion at a proximal end, an anchor portion at a distal end, and a neck portion integral with the capture portion and the anchor portion. The system also includes a plurality of pivoting and non-pivoting receiver sub-assemblies, with each receiver sub-assembly including a receiver having a channel for receiving a rod and a central bore that extends upwardly from a bottom opening through the channel to a top of the receiver, and either a capture portion-engaging retainer or a rod-engaging insert positioned within the central bore. The capture portion of each bone anchor has a single predetermined size and shape that is common with the other bone anchors and is configured for uploading into either the pivoting or non-pivoting receiver sub-assemblies through the bottom opening of the receiver.

Modular bone anchor system with bottom loaded shank heads having a single shank head shape

A receiver assembly includes a receiver with a central bore and a bottom opening, a channel for receiving a rod, and a discontinuous horizontal recess and one or more vertically-aligned side pockets formed into sidewall surfaces of the central bore. The assembly also includes a pressure insert with an upwardly-open rod-seating surface, opposite flanges projecting radially outward from an upper portion of an outer cylindrical surface, and one or more side protuberances projecting radially outward below the opposite flanges. The pressure insert is positionable into the central bore in a first position and then rotatable from the first position to a second position in which the side protuberances are interferingly forced into the side pocket recesses to inhibit further rotation of the pressure insert and the opposite flanges are rotated under downwardly-facing surfaces of the horizontal recess to inhibit upward movement of the pressure insert within the central bore.

Receiver assembly with rotation blocking side pockets for twist-in-place insert and method of assembly

A spinal fixation system includes a plurality of bone anchors and an array of receiver sub-assemblies, with each bone anchor having a common universal capture portion configured for bottom loading into one of the receiver sub-assemblies that includes at least one of a multiplanar receiver sub-assembly, a monoplanar receiver sub-assembly, and a monoaxial receiver sub-assembly that further include, respectively, a multiplanar retainer sub-assembly for providing pivotal motion of the bone anchor relative to the receiver in multiple planes, a monoplanar retainer sub-assembly for limiting pivotal motion of the bone anchor relative to the receiver to a single plane, and a monoaxial retainer sub-assembly for inhibiting all pivotal motion of the bone anchor relative to the receiver while providing of rotation the monoaxial receiver sub-assembly about the longitudinal axis of the bone anchor.

Spinal fixation systems with modular receiver and ring retainer sub-assemblies for connecting with universal shank heads

A media separator, that cooperates with a media pick to form a nip in a feed path of a media handling apparatus, supports a separation pad that includes first and second friction regions for movement relative to the media separator, against a bias force, in a feed direction of a sheet of media through the nip. The first and second friction regions selectively engage the sheet of media passing through the nip with a retard/separation force determined by the bias force, to retard and control a feeding operation of the sheet of media through the nip, and to feed plural sheets of media through the nip one at a time.

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Boise, ID, United States of America

Nathaniel D Ginzton