The present disclosure provides a cannulated bone screw system including a screw with a threaded portion, a non-threaded portion, and a first plurality of teeth spaced apart from a screw head; and a washer with an interior portion with a second plurality of teeth and an opening and an outer portion with a plurality of spikes. The first plurality of teeth are on an inferior convex surface; wherein the second plurality of teeth are on a superior concave surface; and wherein the first plurality of teeth and the second plurality of teeth are operable to mate to prevent the screw from backing out of the washer while allowing the cannulated bone screw system to conform/pivot in order to accommodate different bone morphologies.