Directional control for a multi-axial screw assembly

Patent metadata

Field	Value
Publication number	US-9232969-B2
Application number	US-91563410-A
Country	US
Kind code	B2
Filing date	Oct 29, 2010
Priority date	Oct 29, 2010
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

A multi-axial screw assembly comprises a receiver, a base member, and a crown. The receiver comprises a channel for receiving a rod and an aperture extending from a bottom portion of the receiver. The base member comprises an aperture extending through the base member and an opening on a bottom portion of the base member. The base member is configured to couple to the receiver such that the aperture of the receiver is generally aligned with the aperture of the base member. The base member is rotatable relative to the receiver. The crown is received in the receiver and configured to mate to the base member. The crown has a mating feature configured to couple to the base member such that the crown rotates the base member when the crown is rotated.

First claim

The invention claimed is:

1. A multi-axial screw assembly, comprising:
a receiver defining a longitudinal axis and comprising a channel extending transverse to the longitudinal axis for receiving a rod and an aperture extending parallel to the longitudinal axis between a proximal portion and a distal portion;
a base member comprising an aperture extending parallel to the longitudinal axis through a planar uppermost surface and an opposite bottom surface of the base member and an opening having a convex cutout extending from the bottom surface of the base member into a sidewall of the base member, the base member configured to couple to the receiver such that the aperture of the receiver is generally aligned with the aperture of the base member, the base member being rotatable relative to the receiver;
a crown received in the receiver such that the crown is rotatable relative to the receiver, the crown being configured to mate to the base member, the crown having a width that is less than a width of the distal portion and greater than a width of the proximal portion, the crown having a mating feature configured to couple to the base member such that the crown rotates the base member when the crown is rotated; and
a bone screw located between the base member and the crown such that a head of the bone screw directly engages a concave bottom surface of the crown, the bone screw being movable between a first orientation in which a shaft of the bone screw is parallel to the longitudinal axis and is spaced apart from the cutout and a second orientation in which the shaft is transverse to the longitudinal axis and at least a portion of the shaft is disposed in the cutout.

2. The multi-axial screw assembly of claim 1 , wherein the mating feature includes a surface projection extending from a side wall of the crown.

3. The multi-axial screw assembly of claim 2 , wherein the mating feature includes a plurality of surface projections extending from the side wall of the crown.

4. The multi-axial screw assembly of claim 2 , wherein the crown further comprises an aperture, a wall of the aperture including a gripping surface configured to engage a tool such that the tool rotates the crown.

5. The multi-axial assembly of claim 4 , wherein the crown further comprises a reference, the reference identifying the position of the opening of the base member.

6. The multi-axial assembly of claim 1 , wherein the crown further comprises a reference, the reference identifying the position of the opening of the base member.

7. The multi-axial assembly of claim 6 , wherein the reference is a tool engagement feature on the crown.

8. The multi-axial assembly of claim 1 , wherein the bone screw is configured to rotate within the base member and further configured to be angled into the opening of the base member.

9. The multi-axial assembly of claim 1 , wherein the crown engages a planar surface extending perpendicular to an axis defined by the receiver when the crown is received in the receiver.

10. The multi-axial assembly of claim 1 , wherein the mating feature includes a plurality of surface projections extending from an outer surface of the crown, the projections being uniformly spaced apart and disposed circumferentially about the outer surface of the crown, the projections being disposed in indentations extending into an upper surface of the base member, the indentations being uniformly spaced apart and disposed circumferentially about the upper surface of the base member.

11. The multi-axial assembly of claim 1 , wherein the mating feature includes a plurality of indentations extending into an outer surface of the crown, the indentations being uniformly spaced apart and disposed circumferentially about the outer surface of the crown, the indentations having projections extending from an upper surface of the base member disposed therein, the projections being uniformly spaced apart and extending circumferentially from the upper surface of the base member.

12. The multi-axial assembly of claim 1 , wherein:
an inner surface of the receiver that defines the distal portion comprises a first recess and an outer surface of the base member comprises a second recess; and
the multi-axial assembly further comprising a snap ring positioned within the recesses to rotatably connect the base member with the receiver.

13. The multi-axial assembly of claim 1 , further comprising the rod, wherein the rod engages the uppermost planar surface when the rod is positioned within the channel.

14. The multi-axial assembly of claim 1 , wherein the base member has a maximum width that is greater than that of the aperture of the receiver such that the base member is configured to be bottom-loaded into the aperture of the receiver.

Assignees

• Farris Robert A
• Warsaw Orthopedic Inc

Inventors

• Farris Robert A

Classifications

• Y10T137/0396

  Involving pressure control · CPC title

• G03F7/70991 Primary

  Connection with other apparatus, e.g. multiple exposure stations, particular arrangement of exposure apparatus and pre-exposure and/or post-exposure apparatus; Shared apparatus, e.g. having shared radiation source, shared mask or workpiece stage, shared base-plate; Utilities, e.g. cable, pipe or wireless arrangements for data, power, fluids or vacuum · CPC title

• A61B17/7037

  wherein pivoting is blocked when the rod is clamped · CPC title

• A61B17/7002

  Longitudinal elements, e.g. rods · CPC title

• A61B17/7038 Primary

  to a different extent in different directions, e.g. within one plane only · CPC title