Patent ID: 8500737

Claim:
A bone plate assembly utilizing at least one bone screw for fixation of adjacent bones of a spine comprising: a base plate including at least one aperture defining a through opening extending through the base plate; and a screw retaining mechanism mounted and rotatable within said aperture between locked and unlocked positions relative to said through opening for preventing the bone screw from backing out from said base plate, wherein said screw retaining mechanism includes a center axis and an internal opening eccentric to said center axis and having a ring at least substantially thereabout, and wherein said screw retaining mechanism is rotatable within said aperture about said center axis between said locked and unlocked positions, wherein said internal opening of said screw retaining mechanism is eccentric with said through opening of said base plate when in said locked position and said internal opening of said screw retaining mechanism is concentric with said through opening of said base plate when in said unlocked position.