A method and apparatus for interosseous bone fixation uses a compression staple, generally U-shaped, having a pair of legs with sharp front ends and proximal ends interconnected by a bridge portion, the staple having an initial configuration in which its generally straight legs converge with respect to each other, and capable of a tensioned configuration by resiliently moving and holding the legs in parallel relationship whereby the staple is urged towards its initial configuration with a certain compressive spring force. A staple applicator supports and guides the staple and positions the tensioned staple with its pointed ends forward, adjacent an ejection port at the front of the applicator. A powered strike member is mounted for longitudinal movement in the applicator and has a front end that will strike the rear of the tensioned staple with percussive force and eject it in tensioned condition from the applicator.