A surgical stapling instrument for applying sterilized staples to the disunited skin or fascia of a patient in order to effect a joining of the skin or fascia. The instrument is adapted to associate with a staple-carrying cartridge having a plurality of staples therein. The instrument is manually powered and includes an impact mechanism for forming the staples. A nose portion is rotatably mounted in a hand-held main body portion and adapted to mount the staple-carrying cartridge so that the stapling angle can be varied without rotating the hand-held portion of the stapler. A clutch means is provided for ensuring that the staple-advancing drive means of the instrument is only activated once per stapling operation.