Pedicle screw extension for use in percutaneous spinal fixation
First Claim
1. An anchor extension for releasably coupling to a spinal bone anchor, comprising:
- an elongate hollow outer sleeve having a distal end and a proximal end;
an elongate hollow inner sleeve disposed within said outer sleeve and having a distal end and a proximal end and an inner surface and an outer surface, said outer sleeve and said inner sleeve being movable relative to each other;
an anchor engaging member projecting radially outwardly from the outer surface of the distal end of said inner sleeve for releasably engaging the bone anchor;
a securement member including cooperative interlocking engagement surfaces defined on and adjacent to the distal end of said inner sleeve and said outer sleeve operable upon relative movement of said inner sleeve and said outer sleeve to directly interlock with each other and radially secure said inner sleeve and said outer sleeve together against radial movement for minimization of splaying and to maintain the engagement of said anchor engaging member and said bone anchor; and
a lock between said inner sleeve and said outer sleeve separate and apart from said securement member and spaced proximally of said anchor engaging member operable in a first position to allow said relative movement between said outer sleeve and said inner sleeve and in a second position to prevent such relative movement.
3 Assignments
0 Petitions
Accused Products
Abstract
A bone screw extension assembly for use in placing a connecting rod percutaneously into tissue of a patient comprises a multi-axial bone screw and a screw extension releasably coupled to yoke of the bone screw. The screw extension includes coaxially disposed outer sleeve and inner sleeves that are movable axially relative to each other. A screw engaging member projects radially from the distal end of the inner sleeve and is configured to releasably engage an extension coupling surface on the inner surface of opposed upstanding arms of the yoke. A securement member including cooperative surfaces is defined adjacent the distal end of the inner and outer sleeves that is operable upon relative axial movement of the inner and outer sleeves to radially secure the sleeves together for minimization of splaying and to thereby maintain the engagement of the screw engaging member and the bone screw.
158 Citations
28 Claims
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1. An anchor extension for releasably coupling to a spinal bone anchor, comprising:
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an elongate hollow outer sleeve having a distal end and a proximal end; an elongate hollow inner sleeve disposed within said outer sleeve and having a distal end and a proximal end and an inner surface and an outer surface, said outer sleeve and said inner sleeve being movable relative to each other; an anchor engaging member projecting radially outwardly from the outer surface of the distal end of said inner sleeve for releasably engaging the bone anchor; a securement member including cooperative interlocking engagement surfaces defined on and adjacent to the distal end of said inner sleeve and said outer sleeve operable upon relative movement of said inner sleeve and said outer sleeve to directly interlock with each other and radially secure said inner sleeve and said outer sleeve together against radial movement for minimization of splaying and to maintain the engagement of said anchor engaging member and said bone anchor; and a lock between said inner sleeve and said outer sleeve separate and apart from said securement member and spaced proximally of said anchor engaging member operable in a first position to allow said relative movement between said outer sleeve and said inner sleeve and in a second position to prevent such relative movement. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An anchor extension for releasably coupling to a spinal bone anchor, comprising:
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an elongate hollow outer sleeve having a distal end and a proximal end; an elongate hollow inner sleeve disposed within said outer sleeve and having a distal end and a proximal end and an inner surface and an outer surface, said inner sleeve comprising a pair of opposing flexible arms at the distal end thereof, said outer sleeve and said inner sleeve being movable axially relative to each other; an anchor engaging member projecting radially outwardly from the outer surface of each flexible arm at the distal end of said inner sleeve for releasably engaging the bone anchor; and a securement member including cooperative interlocking engagement surfaces defined on and adjacent to the distal end of said inner sleeve and said outer sleeve operable upon relative movement of said inner sleeve and said outer sleeve in a first axial direction to directly interlock with each other and radially secure said inner sleeve and said outer sleeve together against radial movement for minimization of splaying and to maintain the engagement of said anchor engaging member and said bone anchor; and a release structure between said inner sleeve and said outer sleeve separate and apart from said securement member and spaced proximally of said anchor engaging member operable upon relative movement of said inner sleeve and said outer sleeve in a second axial direction opposite said first axial direction to move said anchor engaging member radially inwardly to cause separation of said anchor engaging member from said bone anchor. - View Dependent Claims (8, 9, 10)
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11. A bone screw extension assembly for use in placing a connecting rod percutaneously into tissue of a patient, comprising:
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a multi-axial bone screw including a shaft having a threaded screw portion and a yoke articulatingly attached to said shaft, said yoke having an exterior surface and a slot therethrough for receiving a connecting rod, said slot defined by a pair of upstanding arms having opposed interior surfaces, said yoke including an extension coupling surface; a screw extension releasably coupled to yoke of said bone screw, said screw extension including an elongate hollow outer sleeve having a distal end and a proximal end and an elongate hollow inner sleeve disposed within said outer sleeve and having a distal end and a proximal end and an inner surface and an outer surface, said outer sleeve and said inner sleeve being coupled together in a manner prior to said screw extension being releasbly coupled to said yoke that allows axial but not rotational movement relative to each other; and a screw engaging member projecting radially outwardly from the outer surface of the distal end of said inner sleeve and configured to flexibly engage said extension coupling surface upon axial movement of said inner sleeve into contact with said bone screw while said inner sleeve is coupled together with said outer sleeve; and a securement member including cooperative interlocking engagement surfaces defined on and adjacent to the distal end of said inner sleeve and said outer sleeve operable upon relative movement of said inner sleeve and said outer sleeve in a first axial direction to directly interlock with each other and radially secure said inner sleeve and said outer sleeve together against radial movement for minimization of splaying and to maintain the engagement of said screw engaging member and said bone screw. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification