A retaining mechanism is disclosed, which comprises aplate including a first surface adapted to engage with animplant and a second opposing surface, the plate havingmechanically-weakened areas, such that the plate iscompressible from a first dimension to a second reduceddimension via the weakened areas, wherein the plate includesat least one ledge adapted to engage with a recess in theimplant to prevent a fixation member inserted into the implantfrom backing out. A tool is also disclosed for compressingand inserting the retaining mechanism into engagement with theimplant, as are respective methods of compression andinsertion of the retaining mechanism into engagement with theimplant.
