Patent ID: 8361126

Claim:
A bone plate system comprising: an elongate plate member having upper and lower surfaces; a plurality of throughbores of the plate member; a plurality of bone anchor members for extending through the throughbore and being driven into bone; a resilient head portion of at least one of the bone anchor members; at least one substantially rigid retainer base member for being received in one of the throughbores; cooperating surfaces of the retainer base member and the one throughbore configured for allowing relative shifting therebetween; a through opening of the substantially rigid retainer base member sized and configured so that compression of the resilient head portion with an insertion tool allows the resilient head portion to be seated in the opening of the rigid retainer base member, with the rigid base member keeping the seated head portion from backing out therefrom, the retainer base member allowing relative shifting between the bone plate member and the one bone anchor member driven into bone with the resilient head portion seated in the retainer base member; a lip of the plate member extending about the one throughbore and defining a narrow portion thereof adjacent the lower surface of the plate member with the lip configured to be in interference with the retainer base member and limit shifting of the retainer base member toward the lower surface of the plate member; a rigid body of the retainer base member extending about the through opening thereof that is configured such that the rigid body resists deformation of the retainer base member with seating of the resilient head portion of the bone anchor member in the through opening of the retainer base member; and at least one access slot in communication with the one throughbore to permit the retainer base member to be inserted therein for receipt of the one bone anchor member extending through the through opening thereof.