Pedicle screw extension for use in percutaneous spinal fixation
First Claim
1. A bone screw extension assembly for use in placing a connecting rod percutaneously into tissue of a patient, comprising:
- 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 and a first holding surface on a side surface of said yoke;
a screw extension releasably coupled to said 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, said outer sleeve and said inner sleeve being movable rotationally relative to each other;
a screw engaging member projecting radially from the distal end of said inner sleeve and configured to engage said extension coupling surface upon relative rotation of said inner sleeve and said outer sleeve;
a securement member including a securement surface defined adjacent the distal end of said inner sleeve and a cooperative securement surface defined adjacent the distal end of said outer sleeve, said securement surface and said cooperative securement surface being operable upon relative rotation of said inner sleeve and said outer sleeve to cooperatively engage and thereby radially secure said inner sleeve and said outer sleeve together and to maintain the engagement of said screw engaging member and said bone screw; and
a second holding surface extending lengthwise on the distal end of said outer sleeve aligned with and engaging said first holding surface for holding said yoke and said outer sleeve together in common against rotation while said inner sleeve rotates relative to said outer sleeve and said yoke.
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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 rotatable relative to each other. A screw engaging member projects radially from the distal end of the inner sleeve and is configured to engage an extension coupling surface on the outer sleeve upon relative rotation of the inner and outer sleeves. A securement member including cooperative surfaces is defined adjacent the distal end of the inner and outer sleeves that is operable upon relative rotation of the inner sleeve and outer sleeve to radially secure the sleeves together to thereby maintain the engagement of the screw engaging member and the bone screw.
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Citations
23 Claims
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1. 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 and a first holding surface on a side surface of said yoke; a screw extension releasably coupled to said 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, said outer sleeve and said inner sleeve being movable rotationally relative to each other; a screw engaging member projecting radially from the distal end of said inner sleeve and configured to engage said extension coupling surface upon relative rotation of said inner sleeve and said outer sleeve; a securement member including a securement surface defined adjacent the distal end of said inner sleeve and a cooperative securement surface defined adjacent the distal end of said outer sleeve, said securement surface and said cooperative securement surface being operable upon relative rotation of said inner sleeve and said outer sleeve to cooperatively engage and thereby radially secure said inner sleeve and said outer sleeve together and to maintain the engagement of said screw engaging member and said bone screw; and a second holding surface extending lengthwise on the distal end of said outer sleeve aligned with and engaging said first holding surface for holding said yoke and said outer sleeve together in common against rotation while said inner sleeve rotates relative to said outer sleeve and said yoke. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. In combination for use during spinal surgery,
a multi-axial bone screw including a shaft having a threaded screw portion, a screw head and a yoke articulatingly attached to said screw head, 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 having an extension coupling surface thereon; -
an elongate hollow screw extension having a distal end and a proximal end, the extension including a screw engaging member at the distal end thereof in engagement with said extension coupling surface on said yoke, said extension having a pair of opposing extension slots opening at the distal end of said extension aligned with said yoke slot and extending for an extent toward the proximal end of said extension, said extension including on an outer surface a persuader coupling member extending for an axial extent more proximal than said slots; and a rod persuader including an elongate hollow sleeve extending over the outer surface of said screw extension, said persuader sleeve being releasably coupled to said persuader coupling member for axial movement relative to said screw extension independently of and without affecting the engagement of said screw engaging member of said extension with the extension coupling surface on said yoke, said persuader sleeve having a distal end defining an axially movable rod engaging surface disposed in a first axial position to allow a rod to be introduced through the opposing slots in said screw extension and operably movable in cooperation with said persuader coupling member to a second axial position wherein said rod engaging surface extends over at least a portion of said extension slots to urge said rod into the slot of said yoke, said rod persuader sleeve including thereon a coupling element releasably coupled directly to said persuader coupling member, said coupling element being configured to couple to and decouple from said persuader coupling member to allow said persuader sleeve to be releasably mounted on and withdrawn from said extension while said extension is in engagement with said yoke, said coupling element and said persuader coupling member forming a rack and pinion arrangement. - View Dependent Claims (15, 16, 17)
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18. In combination for use during spinal surgery,
a multi-axial bone screw including a shaft having a threaded screw portion, a screw head and a yoke articulatingly attached to said screw head, 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 having an extension coupling surface thereon; -
an elongate hollow screw extension having a distal end and a proximal end, the extension including a screw engaging member at the distal end thereof in engagement with said extension coupling surface on said yoke, said extension having a pair of opposing extension slots opening at the distal end of said extension aligned with said yoke slot and extending for an extent toward the proximal end of said extension, said extension including on an outer surface a persuader coupling member extending for an axial extent more proximal than said slots; and a rod persuader including an elongate hollow sleeve extending over the outer surface of said screw extension, said persuader sleeve being releasably coupled to said persuader coupling member for axial movement relative to said screw extension independently of and without affecting the engagement of said screw engaging member of said extension with the extension coupling surface on said yoke, said persuader sleeve having a distal end defining an axially movable rod engaging surface disposed in a first axial position to allow a rod to be introduced through the opposing slots in said screw extension and operably movable in cooperation with said persuader coupling member to a second axial position wherein said rod engaging surface extends over at least a portion of said extension slots to urge said rod into the slot of said yoke, said rod persuader sleeve including thereon a coupling element releasably coupled directly to said persuader coupling member, said coupling element being configured to couple to and decouple from said persuader coupling member to allow said persuader sleeve to be releasably mounted on and withdrawn from said extension while said extension is in engagement with said yoke, said rod persuader including an advancement mechanism driven by a rotatable lever, said coupling element being operably coupled to said lever for axial movement of said rod persuader sleeve relative to said screw extension upon rotation of said lever. - View Dependent Claims (19)
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20. In combination for use during spinal surgery,
a multi-axial bone screw including a shaft having a threaded screw portion, a screw head and a yoke articulatingly attached to said screw head, said yoke having an exterior surface and a slot therethrough for receiving a connecting rod, said slot defined by a pair of upstanding arms each having an interior surface in communication with and on opposite sides of said slot, said yoke having an opening communicating with said screw head and including an extension coupling surface and a fastening surface on each of the interior surfaces of said upstanding arms, said extension coupling surface being more distant from said opening than said fastening surface; -
an elongate hollow screw extension having a distal end and a proximal end, the extension having a rotationally movable screw engaging member projecting radially outwardly from the distal end thereof in direct connection with said extension coupling surface of said yoke arms; and a screw driver including an elongate inner shaft having a distal end and a proximal end and an outer retention sleeve disposed about said inner shaft and having a distal end and a proximal end, the inner shaft being freely rotatable within said outer retention sleeve and having at its distal end a tip extending through said yoke opening in releasable engagement with the head of said bone screw for joint rotational movement therewith, the distal end of said outer retention sleeve being releasably joined at said fastening surface to said yoke for joint movement therewith. - View Dependent Claims (21, 22, 23)
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Specification