A knife assembly for use with a surgical instrument includes a knife having proximal and distal ends, the proximal end including an aperture defined therein having a series of spaced apart fins extending thereacross. A knife drive rod is included and is configured to operably engage the fins to secure the knife drive rod to the knife. A retention mechanism is operably disposed at a distal end of the knife drive rod and is configured to secure the knife drive rod in engagement between the fins.
