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US 2013/0296944 A1Published application
Polyaxial bone screw
OwnerRoger P. Jacksoninventor
Life of this patent
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Abstract
A polyaxial bone screw assembly includes a threaded shank body having an upper capture structure, a head, a retaining ring and a nut. The external capture structure surface includes a threaded portion and a smooth portion; the smooth portion for slidably mating with the retaining ring and the threaded portion for rotatable attachment to the nut within a cavity of the head. The nut fixes the retaining ring to the shank and also provides a tool engagement formation for driving the shank body into bone.
Claims6
A polyaxial bone screw assembly comprising:
- (a) a shank having a body adopted for fixation to a bone and an upper capture structure;
- (b) a head having a cavity and a lower opening communicating with the cavity;
- the opening having a diameter sized and shaped to receive the shank upper capture structure into the cavity;
- (c) a retainer that is downloaded into the cavity and has a diameter larger than the cavity lower opening;
- the retainer having a pass through bore sized and shaped to receive the shank capture structure with the shank extending above the retainer;
- and
- (d) a fastener securable to the shank upper capture structure above the retainer so as to lock the shank and retainer together.
4 more elements
Dependencies are inferred from the claim text.