IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0507282
(2012-06-18)
|
등록번호 |
US-8636769
(2014-01-28)
|
발명자
/ 주소 |
|
출원인 / 주소 |
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
0 인용 특허 :
221 |
초록
▼
A polyaxial bone screw assembly includes a threaded shank body member having an upper portion with an internal drive and, alternatively, a laterally extending alignment rib or fin. The bone screw assembly also includes a lockable receiver coupling member, an open retainer ring member having a slit o
A polyaxial bone screw assembly includes a threaded shank body member having an upper portion with an internal drive and, alternatively, a laterally extending alignment rib or fin. The bone screw assembly also includes a lockable receiver coupling member, an open retainer ring member having a slit or gap and a compression insert member. An inset conical or cylindrical surface on the shank upper portion frictionally engages a similarly shaped inner surface of the retainer ring. The receiver includes a restrictive lower opening that allows for uploading the shank upper portion and compressed retainer ring into the receiver cavity, but prevents passage of the retainer ring out of the receiver once the ring inner surface engages the conical surface of the shank upper portion.
대표청구항
▼
1. A polyaxial bone anchor comprising: a) a shank having a body for fixation to a bone and an upper portion, the body and upper portion being generally aligned along an axis of rotation thereof, the upper portion having an upper surface, a first cylindrical section and a second cylindrical section,
1. A polyaxial bone anchor comprising: a) a shank having a body for fixation to a bone and an upper portion, the body and upper portion being generally aligned along an axis of rotation thereof, the upper portion having an upper surface, a first cylindrical section and a second cylindrical section, the first section being adjacent the upper surface, the first section having a first diameter measured perpendicular to the axis, the second section having a second diameter measured perpendicular to the axis, the second diameter being reduced with respect to the first diameter, the second section being disposed between the body and the first section;b) a receiver having a top portion and a base, the receiver top portion defining an open channel, the base having a 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 receive the shank upper portion therethrough;c) a compression insert disposed in the receiver, the insert having a mating surface exclusively frictionally engageable with the upper surface of the shank upper portion;d) a retainer having a through slit and an internal surface sized and shaped to closely receive the shank upper portion, the shank upper portion and the retainer being secured such that the upper portion and the retainer rotate in unison while being in swivelable relation within the receiver, providing selective angular positioning of the shank with respect to the receiver, the retainer being in slidable engagement with the receiver seating surface, the retainer being substantially spaced from the compression insert at any and all angular positions of the shank with respect to the receiver;e) a resilient structure extending from the receiver and biasing against the compression insert at a depression formed in a surface of the insert, the resilient structure prohibiting rotational movement of the compression insert within the receiver. 2. The bone anchor of claim 1, wherein the compression insert mating surface is concave and the shank upper surface is convex. 3. The bone anchor of claim 1, wherein the receiver seating surface is at least partially spherical and the retainer has an outer at least partially spherical surface. 4. The bone anchor of claim 1, wherein the shank upper portion has a tool engagement formation formed thereon adapted for non-slip engagement by a tool for driving the bone screw shank body into bone. 5. The bone anchor of claim 1, wherein the bone screw shank is cannulated. 6. The bone anchor of claim 1, further comprising a closure structure insertable into the receiver, the closure structure for operably urging the insert into fixed frictional engagement with the bone screw shank upper portion and moving the shank in a direction to frictionally lock the position of the retainer with respect to the receiver, thereby locking the shank body in a selected angle with respect to the receiver. 7. The bone anchor of claim 6 wherein: a) the receiver has upstanding spaced arms defining the open channel, the arms having guide and advancement structures on an inside surface thereof; andb) the closure structure is sized and shaped to be positionable between the arms for closing the channel, the closure structure having a closure guide and advancement structure for rotatably mating with the guide and advancement structures on the arms, biasing the closure structure upon advancement rotation against a longitudinal connecting member disposed in the channel. 8. The bone anchor of claim 1, wherein shank upper portion includes an annular seating surface located between the upper and lower surfaces, the annular seating surface matingly engaging a second annular seating surface of the retainer.
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