Surgical anvil assemblies for surgical stapling instruments

A surgical anvil assembly for use with a circular stapling instrument, comprising:

• an anvil center rod;
• an anvil head pivotally coupled to the anvil center rod and movable between a first, operative condition and a second, tilted condition;
• a backup member slidably disposed within a recess of the anvil head and selectively engagable with the anvil center rod;
• and
• a locking assembly including:
• an inner member supported on an outer surface of the anvil head;
• an outer member movably coupled to the inner member;
• and
• a post interconnecting the outer member and the backup member, wherein the outer member is configured to move relative to the inner member between a first, proximal position, in which the locking assembly maintains the backup member engaged with the anvil center rod to resist movement of the anvil head relative to the anvil center rod, and a second, distal position, in which the locking assembly maintains the backup member disengaged from the anvil center rod to allow for movement of the anvil head relative to the anvil center rod.