| 摘要 |
A lamina hook device which has a rod receiving body portion of variable length. Selected embodiments include a polyaxial coupling element so that the rod receiving channel thereof may be angulated. In each embodiment, the blade portion has a cylindrical recess and the body includes a shaft portion which is slideably mounted therein. The top of the cylindrical recess is slotted, threaded, and tapered to receive a tightening nut. The tightening crush locks the shaft in the recess. In a first embodiment, the upper portion of the body includes a channel in which a rod is a disposed. The rod is locked within the channel by means of a top locking nut or an optional rod securing sleeve. In a second embodiment, the shaft has a semi-spherical head on which a separate coupling element, having a lower and an upper portion, is mounted. The lower portion has a slotted exterior taper and a semi-spherical interior chamber in which the head is initially polyaxially disposed. The upper portion has a channel therein for receiving the rod and a threading for receiving a top locking nut. A locking ring is disposed about the coupling element, at the top thereof, being initially positioned above the bottom of the channel such that the rod seats against the top of the locking ring. As in the first embodiment, a locking nut is provided, along with an optional rod securing sleeve to lock the rod in the recess; the process of doing which causes the locking ring to descend, crush locking the head in the interior chamber.
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