Orthopedic anti back-out mechanism

摘要

A bone plate that is inserted into a vertebral column includes a hole, an eccentrically-shaped annulus, and a channel. The hole includes an eccentrically-shaped sidewall and the annulus includes an aperture positioned on an upper surface of the annulus. The hole is configured to receive a bone screw. The channel is positioned adjacent to the sidewall and adapted to hold the annulus. The channel may permit the annulus to rotate with respect to the sidewall. The channel may include a notch and the annulus may include a flared end. The flared end may be adapted to fit into the notch of the channel. A portion of the annulus may be adapted to cover a portion of the bone screw. As the annulus rotates with respect to the sidewall, the portion of the annulus may cover the portion of the bone screw.

主权项

1. A system for providing stability to a vertebral column, said system comprising:
a substantially rectangular plate comprising:
a top surface;a bottom surface oppositely positioned from said top surface;a plurality of projections extending from each corner and central side areas of said plate;a plurality of openings extending from said top surface to said bottom surface through said plate; anda plurality of holes separate from said plurality of openings and configured in said plurality of projections and extending from said top surface to said bottom surface through said plate, wherein each hole of said plurality of holes are dimensioned and configured to accommodate a bone screw, wherein each said hole comprises:
an eccentrically-shaped anti back-out ring configured to rotate from an unlocked position to a locked position and comprising a thin end and a thick end, wherein said thick end comprises exactly one aperture; andan angled eccentrically-shaped sidewall contacting the anti back-out ring,wherein said anti back-out ring is a continuous structure and is rotatably seated adjacent to the sidewall in said hole, andwherein said thick end of said anti back-out ring covers a portion of a head of said bone screw upon said anti back-out ring being configured in said locked position.