POLYAXIAL SCREWDRIVER FOR A PEDICLE SCREW SYSTEM
5 Assignments
0 Petitions
Accused Products
Abstract
A polyaxial screwdriver for inserting a bone screw in a vertebra. A polyaxial bone screw assembly includes a coupling element. When a screw engaging end of the polyaxial screwdriver is lowered on the head of the bone screw, the complimentary surfaces of the screw engaging end of the screwdriver and the head of the screw self-align. A ratchet mechanism formed in the screwdriver provides progressive and automatic locking of the polyaxial screwdriver to the coupling element and prevents the accidental unthreading from the coupling element. In another embodiment of the polyaxial screwdriver, a collet slides over the outside surface of the upper end of the coupling element and locks on to the coupling element. In yet another embodiment of a polyaxial screwdriver, the outer sleeve of the polyaxial screwdriver has a split end that securely engages the coupling element.
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Citations
40 Claims
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1-20. -20. (canceled)
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21. A pedicle screw system comprising:
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a polyaxial bone screw assembly including a bone screw polyaxially coupled to a coupling element, the bone screw having a threaded portion and a head, and the coupling element having a bore with internal threads; and a polyaxial screwdriver including a shaft and a sleeve slidably received over the shaft, the shaft having a screw engaging end engageable with the head of the bone screw, the polyaxial screwdriver having external threads formed thereon for engaging the internal threads of the coupling element to securely attach the polyaxial screwdriver to the polyaxial bone screw assembly, and the polyaxial screwdriver including a locking mechanism operable between an engaged state and a disengaged state, the locking mechanism preventing the external threads from disengaging from the internal threads of the coupling element when the locking mechanism is in the engaged state. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28)
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29. A pedicle screw system comprising:
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a polyaxial bone screw assembly including a bone screw polyaxially coupled to a coupling element, the bone screw having a threaded portion at a distal end of the bone screw and a head at a proximal end of the bone screw, and the coupling element having a bore adapted to receive the head of the bone screw therein, wherein the head of the bone screw includes a first engagement structure; and a polyaxial screwdriver including a shaft having a screw engaging end engageable with the head of the bone screw, the screw engaging end including a second engagement structure adapted to securely mate with the first engagement structure of the bone screw so as to allow the threaded portion of the bone screw to be advanced into bone in response to force exerted by the polyaxial screwdriver; wherein the head of the bone screw includes a plurality of sloping portions arranged to engage the screw engaging end of the polyaxial screwdriver so as to cause the first and second engagement structures to move into alignment such that the first engagement structure mates with the second engagement structure. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
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Specification