An adapter assembly for connecting an end effector to an actuation assembly includes a base member defining a plurality of notches spaced at least partially about a circumference of the base member, a handle supported on the base member and rotatable about a longitudinal axis of the base member, and a latch mechanism supported on the handle assembly and selectively engageable with the base member. The latch mechanism includes a button member and a locking member. The button member is movable between a first position in which the locking member is received within one of the plurality of notches to lock the handle relative to the base member, and a second position in which the locking member is spaced from the plurality of notches to unlock the handle relative to the base member.