Staple cartridge comprising a tissue thickness compensator

A staple cartridge, comprising:

• a cartridge body, comprising:
• a plurality of staple cavities arranged in a plurality of rows, wherein the plurality of rows comprises a first row and a second row;
• and
• a well defined into the cartridge body, wherein the well extends between one of the staple cavities in the first row and one of the staple cavities in the second row;
• a plurality of staples removably positioned in the staple cavities;
• and
• a tissue thickness compensator releasably secured to the cartridge body, wherein the tissue thickness compensator comprises:
• a compensator body;
• and
• an extension extending from the compensator body into the well, wherein the extension is compressed within the well.

A staple cartridge, comprising:

• a cartridge body, comprising:
• a proximal end and a distal end;
• a knife slot extending from the proximal end toward the distal end;
• a plurality of staple cavities;
• and
• a plurality of recesses, wherein each recess surrounds at least one staple cavity;
• a plurality of staples removably positioned in the staple cavities;
• and
• a tissue thickness compensator releasably secured to the cartridge body, wherein the tissue thickness compensator comprises:
• a compensator body;
• and
• a plurality of extensions extending from the compensator body into the recesses, wherein at least one extension is compressed within one of the recesses.

A staple cartridge, comprising:

• a cartridge body, comprising:
• a proximal end, a distal end, and an axis extending between the proximal end and the distal end;
• a slot extending along at least a portion of the axis;
• a plurality of staple cavities;
• and
• a plurality of depressions, wherein at least one depression is positioned around at least a portion of two adjacent staple cavities;
• a plurality of staples removably positioned in the staple cavities;
• and
• a tissue thickness compensator releasably secured to the cartridge body, wherein the tissue thickness compensator comprises:
• a compensator body;
• and
• a plurality of protrusions protruding from the compensator body, wherein the protrusions are closely retained in the depressions defined in the cartridge body.