A surgical apparatus is disclosed. An actuation mechanism is operable from a proximal portion of the surgical apparatus and a tool assembly is pivotally positioned on a distal portion of the surgical apparatus. The tool assembly is movable between a first position in which the tool assembly is substantially aligned with a longitudinal axis of the surgical apparatus, and a second position in which the tool assembly is pivoted away from the longitudinal axis of the surgical apparatus. An articulation mechanism is positionable to move the tool assembly between the first and second positions. A drive mechanism includes a first shaft operably engaged with a second shaft at an articulation joint. The drive mechanism is configured to transfer rotational motion from the first shaft to the second shaft.