A fastener for attaching a sheet-like implant to tissue or bone may be provided with a first arm having a proximal portion and a distal portion, a second arm having a proximal portion and a distal portion, and a bridge formed at least in part by the proximal portion of the first arm overlapping the proximal portion of the second arm. Each of the first and second arms can include at least a partial loop member having a lumen therethrough slidably receiving the other arm, each arm further including a tissue retention member on a distal portion having a projection extending therefrom for engagement of bone or tissue when inserted therein. The staple can also include a one-way position retention assembly for allowing distal movement of each at least partial loop member relative to the other arm therethrough to tension the fastener and maintain a desired configuration.