Polyaxial screw

摘要

The present invention generally is directed toward a spinal fixation system whereby a coupling element allows the physician to selectively lock or unlock either the connection between the coupling element and a fastener, such as to allow for repositioning of the coupling element, or the connection between the coupling element and an elongate rod. The locking or unlocking of these connections may be made independently and as desired by the physician.

主权项

1. A surgical system comprising:
a fastener for insertion into a bone member, the fastener including a head portion and a shaft portion; a coupling body for receiving the fastener, wherein the coupling body comprises a seat portion and a pair of tines extending upwardly from the seat portion, and a cap for engaging the coupling body, wherein the cap comprises a rim extending along at least a part of an exterior circumference of a top portion of the cap, wherein the rim is configured to rest on an upper surface of the coupling body, and wherein at least a part of the rim remains above an upper most surface of the coupling body when the cap is engaged with the coupling body, wherein the rim protrudes laterally outward from the coupling body such that it has a diameter that is greater than a diameter of an adjacent portion of the coupling body, wherein the rim of the cap is received in a groove that is formed in the coupling body, wherein the groove extends below an uppermost surface of the coupling body, wherein the groove is positioned between the pair of tines, wherein the rim of the cap that is received in the groove is non-threaded.