Bone anchors with longitudinal connecting member engaging inserts and closures for fixation and optional angulation
First Claim
1. A polyaxial bone screw assembly comprising:
- a) a shank having an elongate body and an upper portion, the body being configured for fixation to a bone;
b) a receiver having a top portion and a base, the receiver top portion defining a channel to receive a longitudinal connecting member, the base having an internal seating surface partially defining a cavity, the channel communicating with the cavity, the cavity communicating with an exterior of the base through an opening sized and shaped to upwardly load the shank upper portion through the opening;
c) a retainer having at least two discrete parts, each part having an inner surface and an outer surface, the inner surface configured to be engagement with the shank upper portion and the outer surface configured to be in engagement with the receiver seating surface when the retainer is captured between the shank upper portion and the seating surface, the discrete parts cooperating to prevent the shank upper portion from passing down through the receiver opening, and wherein the parts can move with the shank in polyaxial rotation with respect to the receiver;
d) a compression insert disposed within the receiver and configured to frictionally engage the shank upper portion at a location spaced from the retainer; and
e) a closure structure directly engaging the compression insert, the closure structure placing a downward force on the compression insert, the compression insert placing a downward force on the shank upper portion to lock the shank with respect to the receiver.
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Accused Products
Abstract
Polyaxial bone anchors include a retainer for holding a shank within a receiver, the retainer being in at least two discrete pieces and cooperating with a variety of inserts, some of which independently lock the polyaxial mechanism. Polyaxial and mono-axial bone anchor assemblies include pivot and/or pressure inserts or pads that cooperate with longitudinal connecting members to provide a desired degree of continued control of angulation of the longitudinal connecting member in the sagittal plane or to hold the connecting member in place. Pressure pads for deformable rods may also be made from a deformable plastic material.
139 Citations
23 Claims
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1. A polyaxial bone screw assembly comprising:
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a) a shank having an elongate body and an upper portion, the body being configured for fixation to a bone; b) a receiver having a top portion and a base, the receiver top portion defining a channel to receive a longitudinal connecting member, the base having an internal seating surface partially defining a cavity, the channel communicating with the cavity, the cavity communicating with an exterior of the base through an opening sized and shaped to upwardly load the shank upper portion through the opening; c) a retainer having at least two discrete parts, each part having an inner surface and an outer surface, the inner surface configured to be engagement with the shank upper portion and the outer surface configured to be in engagement with the receiver seating surface when the retainer is captured between the shank upper portion and the seating surface, the discrete parts cooperating to prevent the shank upper portion from passing down through the receiver opening, and wherein the parts can move with the shank in polyaxial rotation with respect to the receiver; d) a compression insert disposed within the receiver and configured to frictionally engage the shank upper portion at a location spaced from the retainer; and e) a closure structure directly engaging the compression insert, the closure structure placing a downward force on the compression insert, the compression insert placing a downward force on the shank upper portion to lock the shank with respect to the receiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A polyaxial bone screw assembly comprising:
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a) a shank having an elongate body and an upper portion, the body being configured for fixation to a bone; b) a receiver having a top portion and a base, the receiver top portion defining a channel to receive a longitudinal connecting member, the base having an internal seating surface partially defining a cavity, the channel communicating with the cavity, the cavity communicating with an exterior of the base through an opening sized and shaped to upwardly load the shank upper portion through the opening; c) a retainer having at least two discrete parts, each part having an inner surface and an outer surface, the inner surface configured to be engagement with the shank upper portion and the outer surface configured to be in engagement with the receiver seating surface when the retainer is captured between the shank upper portion and the seating surface, the discrete parts cooperating to prevent the shank upper portion from passing down through the receiver opening, and wherein the parts can move with the shank in polyaxial rotation with respect to the receiver; d) a compression insert disposed within the receiver and having arms extending upwardly into the channel, the insert configured to frictionally engage the shank upper portion at a location spaced from the retainer and engage a closure structure at the arms. - View Dependent Claims (21)
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22. A polyaxial bone screw assembly comprising:
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a) a shank having an elongate body and an upper portion, the body being configured for fixation to a bone; b) a receiver having a top portion and a base, the receiver top portion defining a channel to receive a longitudinal connecting member, the base having an internal seating surface partially defining a cavity, the channel communicating with the cavity, the cavity communicating with an exterior of the base through an opening sized and shaped to upwardly load the shank upper portion through the opening; c) a retainer having an inner surface and an outer surface, the inner surface configured to be in engagement with the shank upper portion and the outer surface configured to be in engagement with the receiver seating surface when the retainer is captured between the shank upper portion and the seating surface, the retainer preventing the shank upper portion from passing down through the receiver opening and the retainer moving with the shank in polyaxial rotation with respect to the receiver; d) a compression insert disposed within the receiver the insert sized and shaped to frictionally engage the shank upper portion at a location spaced from the retainer; e) at least one of a discrete pivot insert and a discrete compression pad located in a recess of the compression insert and having a first surface engaging a longitudinal connecting member and an opposed second surface engaging the shank upper portion. - View Dependent Claims (23)
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Specification