Patent ID: 8734495

Claim:
A fastener insertable within an implant in a body, the implant having an aperture through which the fastener may be inserted, the aperture including a curved inner profile defining a larger dimension and a smaller dimension, the fastener comprising: an elongated body; a head connected to said body and defining a curved profile mateable with the curved inner profile of the implant, said head further including a circumferential groove disposable proximate the larger dimension of the curved inner profile of the implant when said head is mated with said implant; and an open ring sized to be positionable partly within said circumferential groove to extend from said circumferential groove to thereby increase a widest dimension of said head, said ring formed with a resilient material, said ring resiliently expandable from a first compressed configuration having a first dimension to a second relaxed configuration having a second dimension, said ring further including a first end and a second end, said first end fixed within said circumferential groove, and said second end moveable to change a shape of said ring from said first compressed configuration to said second relaxed configuration, said second end including a notch releasably engageable to maintain said ring in said first compressed configuration, said second dimension larger than said first dimension, said head passable into the aperture when said ring is assembled into said groove and said ring is in said first compressed configuration, and said head not passable out of the aperture when said ring is resiliently expanded to said second configuration, due to said ring interfering in said second configuration with the smaller dimension of the curved inner profile.