Articulatable surgical stapling instruments

1. A surgical stapling system, comprising:

an end effector configurable in an open configuration and a second configuration, comprising:

a first jaw; and

a second jaw;

a firing cam bar movable from an unfired position toward a fired position during a firing stroke, wherein said firing cam bar comprises a first cam that engages said first jaw during said firing stroke and a second cam that engages said second jaw during said firing stroke;

an elongate shaft;

a series of articulation joints, wherein said end effector is rotatable relative to said elongate shaft about said series of articulation joints;

an articulation actuator positioned to transfer an input to a rotation of said elongate shaft via at least one of said series of articulation joints;

a flexible firing bar extending through said series of articulation joints, wherein said flexible firing bar is configured to drive said firing cam bar toward said fired position during said firing stroke, and wherein said flexible firing bar comprises a circular cross-sectional profile; and

a longitudinally-translatable driver, wherein longitudinal translation of said longitudinally-translatable driver drives longitudinal translation of said flexible firing bar.

2. The surgical stapling system of claim 1 , further comprising a lockout configured to prevent said firing cam bar from moving through said firing stroke unless an unfired staple cartridge is positioned within said first jaw.

3. The surgical stapling system of claim 1 , wherein said end effector further comprises a window, and wherein said firing cam bar is viewable through said window when said firing cam bar is in said unfired position.

4. The surgical stapling system of claim 1 , further comprising a rotation shaft configured to rotate said end effector about a longitudinal axis defined by said elongate shaft, wherein said rotation shaft is configured to rotate said end effector relative to said series of articulation joints.

5. The surgical stapling system of claim 1 , wherein said series of articulation joints comprises:

a first joint comprising a recess; and

a second joint comprising a protrusion, wherein said protrusion is configured to nest within said recess to limit twisting of said series of said articulation joints.

6. The surgical stapling system of claim 1 , wherein said articulation actuator comprises a plurality of cables, and wherein said cables are configured to longitudinally restrain said series of articulation joints.

7. The surgical stapling system of claim 1 , wherein said end effector further comprises a staple cartridge comprising a deck and a base, and wherein said flexible firing bar is configured to move between said deck and said base as said flexible firing bar moves said firing cam bar toward said fired position.

8. A surgical stapling system, comprising:

an end effector, comprising:

a first jaw; and

a second jaw, wherein said first jaw and said second jaw are positionable relative to one another between an open configuration and a closed configuration;

a firing cam bar movable from an unfired position toward a fired position during a firing stroke;

an elongate shaft;

a series of articulation vertebrae, wherein said end effector is rotatable relative to said elongate shaft about said series of articulation vertebrae;

an articulation actuator configured to rotate said end effector relative to said elongate shaft via at least one of said series of articulation vertebrae;

a flexible firing rod extending through said series of articulation vertebrae, wherein said flexible firing rod is configured to drive said firing cam bar toward said fired position, and wherein said flexible firing rod comprises a round cross-sectional profile; and

a longitudinally-translatable driver, wherein longitudinal translation of said longitudinally-translatable driver drives longitudinal translation of said flexible firing rod.

9. The surgical stapling system of claim 8 , wherein said end effector further comprises a staple driver drivable within said end effector by said firing cam bar.

10. The surgical stapling system of claim 8 , further comprising a lockout configured to prevent said firing cam bar from moving through said firing stroke unless an unfired staple cartridge is positioned within said end effector.

11. The surgical stapling system of claim 8 , wherein said end effector further comprises a window, and wherein said firing cam bar is viewable through said window when said firing cam bar is in said unfired position.

12. The surgical stapling system of claim 8 , further comprising a rotation shaft configured to rotate said end effector about a longitudinal axis defined by said elongate shaft, wherein said rotation shaft is configured to rotate said end effector relative to said series of articulation vertebrae.

13. The surgical stapling system of claim 8 , wherein said series of articulation vertebrae comprises:

a first vertebrae comprising a recess; and

a second vertebrae comprising a protrusion, wherein said protrusion is configured to nest within said recess to limit twisting of said series of articulation vertebrae.

14. The surgical stapling system of claim 8 , wherein said articulation actuator comprises a plurality of cables, and wherein said cables are configured to longitudinally restrain said series of articulation vertebrae.

15. The surgical stapling system of claim 8 , wherein said end effector further comprises a staple cartridge, and wherein said flexible firing rod is configured to move within said staple cartridge as said flexible firing rod moves said firing cam bar toward said fired position.

16. The surgical stapling system of claim 8 , wherein said firing cam bar is movable through:

a closure stroke in which said firing cam bar moves said second jaw from said open configuration toward said closed configuration; and

said firing stroke subsequent to said closure stroke.

17. A surgical stapling system, comprising:

an end effector, comprising:

an anvil; and

an elongate channel, wherein said anvil and said elongate channel are configurable between an open configuration and a closed configuration;

a firing driver movable from an unfired position toward a fired position during a firing stroke;

an elongate shaft;

a flexible spine, wherein said end effector is rotatable relative to said elongate shaft about said flexible spine, and wherein said flexible spine comprises a series of articulation vertebrae;

an articulation actuator configured to position said end effector relative to said elongate shaft about said flexible spine;

a flexible firing shaft extending through said flexible spine, wherein said flexible firing shaft is configured to drive said firing driver between said unfired position and said fired position, and wherein said flexible firing shaft comprises a circular cross-sectional profile; and

a longitudinally-translatable driver, wherein longitudinal translation of said longitudinally-translatable driver drives longitudinal translation of said flexible firing shaft.

18. The surgical stapling system of claim 17 , further comprising a lockout configured to prevent said firing driver from moving through said firing stroke unless an unfired staple cartridge is positioned within said elongate channel.

19. The surgical stapling system of claim 17 , wherein said end effector further comprises a window, and wherein said firing driver is viewable through said window when said firing driver is in said unfired position.

20. The surgical stapling system of claim 17 , wherein said articulation actuator comprises a plurality of cables, and wherein said cables are configured to longitudinally restrain said series of articulation vertebrae.

21. The surgical stapling system of claim 17 , wherein said end effector further comprises a fastener cartridge, wherein said flexible firing shaft is configured to move through said fastener cartridge as said flexible firing shaft moves said firing driver toward said fired position.