A surgical instrument configured to apply tacks to tissue, the surgical instrument comprising: a handle assembly ; an elongated portion extending distally from the handle assembly and defining a first longitudinal axis, the elongated portion comprising an outer tube extending distally from the handle assembly and an inner shaft assembly ; and an end effector attached to a distal end of the elongated portion and configured to house a plurality of tacks therein, the end effector defining a second longitudinal axis and being able to articulate with respect to the first longitudinal axis; wherein a predetermined amount of rotation of the inner shaft assembly with respect to the outer tube is configured to cause distal advancement and ejection of at least one tack from within the end effector ; the surgical instrument being characterized in that it further comprises: a rotation assembly configured to rotate at least a portion of the outer tube about the first longitudinal axis and with respect to the handle assembly, the rotation assembly including a rotation knob rotationally fixed to a proximal portion of the outer tube such that rotation of the rotation knob is configured to cause rotation of the outer tube ; and a rotation-limiting structure disposed in mechanical cooperation with the rotation assembly and the handle assembly , and configured to limit an amount of rotation of the outer tube with respect to the handle assembly. a handle assembly ; an elongated portion extending distally from the handle assembly and defining a first longitudinal axis, the elongated portion comprising an outer tube extending distally from the handle assembly and an inner shaft assembly ; and an end effector attached to a distal end of the elongated portion and configured to house a plurality of tacks therein, the end effector defining a second longitudinal axis and being able to articulate with respect to the first longitudinal axis; wherein a predetermined amount of rotation of the inner shaft assembly with respect to the outer tube is configured to cause distal advancement and ejection of at least one tack from within the end effector ; the surgical instrument being characterized in that it further comprises: a rotation assembly configured to rotate at least a portion of the outer tube about the first longitudinal axis and with respect to the handle assembly, the rotation assembly including a rotation knob rotationally fixed to a proximal portion of the outer tube such that rotation of the rotation knob is configured to cause rotation of the outer tube ; and a rotation-limiting structure disposed in mechanical cooperation with the rotation assembly and the handle assembly , and configured to limit an amount of rotation of the outer tube with respect to the handle assembly. a rotation assembly configured to rotate at least a portion of the outer tube about the first longitudinal axis and with respect to the handle assembly, the rotation assembly including a rotation knob rotationally fixed to a proximal portion of the outer tube such that rotation of the rotation knob is configured to cause rotation of the outer tube ; and a rotation-limiting structure disposed in mechanical cooperation with the rotation assembly and the handle assembly , and configured to limit an amount of rotation of the outer tube with respect to the handle assembly. <EOS>