A surgical instrument and a fastener for deployment by said surgical instrument, the fastener having a head and a shaft extending from the head, the surgical instrument comprising: a handle ; an elongated shaft assembly extending distally from the handle ; and a fastener deployment system including a substantially tubular driveshaft , the lumen of the tubular driveshaft forming an internal channel, the driveshaft being disposed within the elongated shaft assembly ; wherein the driveshaft has a longitudinal axis and the internal channel extends along the longitudinal axis and is configured to receive the fastener such that the fastener is wholly received in the internal channel of the driveshaft ; wherein the head and the shaft of the fastener are aligned with the longitudinal axis of the driveshaft; wherein the internal channel and the fastener have complementary round portions on an internal surface of the internal channel of the driveshaft and on an external surface of the head of the fastener respectively, the round portions being sized and shaped to correspond to one another, wherein said round portions face each other when the fastener is received in the internal channel of the driveshaft , the fastener deployment system being configured to linearly reciprocate the drive shaft without causing it to rotate, between a proximal position and a distal position to apply a deployment force to a fastener in a fastener deployment position, the surgical instrument further comprising a guide surface on the internal surface of the internal channel of the driveshaft, and the fastener further comprising a surface on its external surface, wherein the guide surface and the surface are sized and shaped to interact to maintain an orientation of the fastener in the internal channe. a handle ; an elongated shaft assembly extending distally from the handle ; and a fastener deployment system including a substantially tubular driveshaft , the lumen of the tubular driveshaft forming an internal channel, the driveshaft being disposed within the elongated shaft assembly ; wherein the driveshaft has a longitudinal axis and the internal channel extends along the longitudinal axis and is configured to receive the fastener such that the fastener is wholly received in the internal channel of the driveshaft ; wherein the head and the shaft of the fastener are aligned with the longitudinal axis of the driveshaft; wherein the internal channel and the fastener have complementary round portions on an internal surface of the internal channel of the driveshaft and on an external surface of the head of the fastener respectively, the round portions being sized and shaped to correspond to one another, wherein said round portions face each other when the fastener is received in the internal channel of the driveshaft , the fastener deployment system being configured to linearly reciprocate the drive shaft without causing it to rotate, between a proximal position and a distal position to apply a deployment force to a fastener in a fastener deployment position, the surgical instrument further comprising a guide surface on the internal surface of the internal channel of the driveshaft, and the fastener further comprising a surface on its external surface, wherein the guide surface and the surface are sized and shaped to interact to maintain an orientation of the fastener in the internal channe. <EOS>