An end effector actuation system includes a shaft assembly having an outershaft withan internal lumen and an actuation rod slidably received in the lumen, theouter shaft havinga distal end portion that is compressible only when the actuation rod isabsent from the lumenin the distal end portion, a locking boss provided on the distal end portion；and an end effectorassembly having a receiving opening and a retention pocket, wherein thereceiving openingis sized to receive the compressed distal end portion of the outer shaft andthe retention pocketis sized to receive the locking boss when the distal end portion isuncompressed due to thepresence of the actuation rod in the lumen of the distal end portion.
