Surgical anvil assemblies for surgical stapling instruments

A cut ring assembly configured for slidable receipt in an anvil head of a circular stapling instrument, the ring assembly comprising:

• a backup member;
• and
• a cut ring disposed on the backup member and including:
• an annular inner body portion;
• and
• an annular outer body portion extending radially outward of the inner body portion, the outer body portion being configured to disconnect from the inner body portion upon an advancement of an annular knife through the cut ring, wherein the backup member supports the inner body portion and the outer body portion thereon.

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

• an anvil head configured to be pivotally coupled to an anvil center rod and movable between a first, operative condition and a second, tilted condition, the anvil head defining a recess therein and a groove extending radially outward from the recess;
• and
• a ring assembly including:
• a backup member disposed within the recess of the anvil head;
• and
• a cut ring disposed on the backup member and captured in the groove of the anvil head, wherein the ring assembly is movable within the recess from a proximal position preventing pivotal movement of the anvil head from the first, operative condition, to a distal position permitting pivotal movement of the anvil head to the second, tilted condition.