A surgical instrument for treating a patient includes a shaft assembly and a body assembly. The shaft assembly includes an articulation joint that is operable to selectively articulate a distal end portion relative to a proximal end portion. The body assembly includes a joint drive assembly, an actuator, and a clutch lock mechanism. The clutch lock mechanism is operatively connected between the actuator and the joint drive assembly. The actuator is configured to actuate the clutch lock mechanism from a locked state to an unlocked state. In the locked state, the clutch lock mechanism is configured to seize the joint drive assembly and inhibit movement of the articulation joint. In the unlocked state, the clutch lock mechanism is configured to transmit movement of the actuator to the joint drive assembly for moving the distal end portion of the shaft assembly.