A surgical instrument (810, 810', 810") comprising: a handle assembly; a flexible spine assembly (820, 820') operably coupled to said handle assembly and protruding therefrom; an elongated shaft assembly (830, 830', 830") received on said flexible spine assembly (820, 820') and having a reconfigurable shaft segment that is selectively reconfigurable between a linear configuration wherein all portions of said reconfigurable shaft segment are substantially coaxially aligned with each other and configurations wherein at least one said portion of said reconfigurable shaft segment is orientated in a non-linear orientation relative to at least one other said portion of said reconfigurable shaft segment, said elongated shaft assembly (830, 830', 830") further having a closure tube segment that is axially movable relative to said reconfigurable shaft segment in response to firing motions applied thereto from a firing system operably supported in said handle assembly; an end effector (612, 612') coupled to said flexible spine assembly (820, 820') and having first and second jaw members (613, 615) movable relative to each other from an open position to closed positions in response to axial movement of said closure tube segment; wherein said reconfigurable shaft segment of said elongated shaft assembly (830, 830', 830") comprises a plurality of movably interconnected tubular links (852, 872) that cooperate to form a hollow passage (858, 878) therethrough to operably support said flexible spine assembly (820, 820') therein, and said at least one portion of said reconfigurable shaft segment can be orientated in non-linear orientations in any radial direction relative to said at least one other portion of said reconfigurable shaft segment by relative movement of said movably interconnected tubular links (852, 872); and a locking means (862, 864, 868; 882, 884) for locking said reconfigurable shaft segment of said elongated shaft assembly (830, 830', 830") in any one of a plurality of desired non-linear orientations. a handle assembly; a flexible spine assembly (820, 820') operably coupled to said handle assembly and protruding therefrom; an elongated shaft assembly (830, 830', 830") received on said flexible spine assembly (820, 820') and having a reconfigurable shaft segment that is selectively reconfigurable between a linear configuration wherein all portions of said reconfigurable shaft segment are substantially coaxially aligned with each other and configurations wherein at least one said portion of said reconfigurable shaft segment is orientated in a non-linear orientation relative to at least one other said portion of said reconfigurable shaft segment, said elongated shaft assembly (830, 830', 830") further having a closure tube segment that is axially movable relative to said reconfigurable shaft segment in response to firing motions applied thereto from a firing system operably supported in said handle assembly; an end effector (612, 612') coupled to said flexible spine assembly (820, 820') and having first and second jaw members (613, 615) movable relative to each other from an open position to closed positions in response to axial movement of said closure tube segment; wherein said reconfigurable shaft segment of said elongated shaft assembly (830, 830', 830") comprises a plurality of movably interconnected tubular links (852, 872) that cooperate to form a hollow passage (858, 878) therethrough to operably support said flexible spine assembly (820, 820') therein, and said at least one portion of said reconfigurable shaft segment can be orientated in non-linear orientations in any radial direction relative to said at least one other portion of said reconfigurable shaft segment by relative movement of said movably interconnected tubular links (852, 872); and a locking means (862, 864, 868; 882, 884) for locking said reconfigurable shaft segment of said elongated shaft assembly (830, 830', 830") in any one of a plurality of desired non-linear orientations.