A surgical instrument that includes a distal member configured to receive a pneumatically operated tool assembly therein. The instrument may also include an elongate shaft assembly that has a distal end portion that is coupled to the distal member and a proximal end portion. A pneumatically powered rotary drive member may be supported by the distal end portion of the elongate shaft assembly and may be configured to apply at least two rotary actuation motions to the pneumatically operated tool assembly upon receipt of at least one pneumatic drive signal from a source of pneumatic power. The pneumatically powered drive member may comprise a pneumatically powered motor. In various embodiments, the distal end portion of the elongate shaft member may articulate relative to the proximal end portion thereof and/or the distal end portion of the elongate shaft assembly may be detachable from the proximal end portion.