A staple includes a length of metal wire shaped to form a crown and two spikes. Each spike depends from a respective end of the crown and includes a shoulder at each end of the crown, a sharpened tip portion and an elbow interposed between each tip portion and shoulder, the elbow comprised of a proximal limb and a distal limb such that the tip portions depend from respective distal limbs. An included angle between each shoulder and the crown is between about 91° and 96°, an included angle between each proximal limb and the crown is between about 60° and 85° and an included angle between each distal limb and the crown is between about 95° and 130°.
