Spinal implant

摘要

A screw and rod fixation assembly includes a body member including a screw seat for seating a screw head therein and a rod seat for seating a rod therein. An adjustable locking ring applies a locking force against the screw head seated in the screw seat and a locking cap adjustably applies a locking force against a rod seated in the rod seat. The adjustable screw locking ring and locking cap function independent of each other.;A method of fixing the rod to the screw includes the steps of inserting a screw head into a screw seat in one end of a body member and inserting a rod into a rod seat in a second end of a body member and selectively and independently adjusting a locking force on both the screw head and the rod within the screw seat and rod seat, respectively.

主权项

1. A screw and rod fixation assembly, comprising:
a body member including:
a screw seat:
having internal walls shaped to seat a screw head therein;having a maximum internal diameter; anddefining a screw head opening having a diameter less than the maximum internal diameter;a cylindrical outer surface disposed at least partially about the screw seat, the cylindrical outer surface having at least one slot shaped to permit flexing of the cylindrical outer surface; anda rod seat shaped to seat a rod therein opposite the screw seat; and a screw having a head with a maximum outer diameter larger than the maximum internal diameter such that, when the head of the screw is inserted through the screw head opening and into the screw seat, the internal walls of the screw seat frictionally interfere with the head and force a portion of the cylindrical outer surface to flex outward and change a portion of the cylindrical outer surface into a tapered outer surface section.