Abstract: Various mechanisms are provided for use in a surgical instrument. A shaft and an engaged lost motion operating knob are provided for rotation relative to a handle portion. A latch system prevents rotation of the shaft unless the shaft is rotated by the knob. A cartridge is provided for rotation at the distal end of the shaft. Engaging structures are provided for preventing rotation of the cartridge relative to the shaft when axial forces are applied to the cartridge. A loading tool is provided for engaging the cartridge to install the cartridge on the instrument. The cartridge includes a washer for engaging a carrier on which the cartridge is mounted so as to prevent rotation of the washer. The washer is adapted to engage a fastener advancing member in a first angular orientation and is disengaged when the cartridge is rotated to establish a second relative angular orientation.