Endoskopisches chirurgisches Instrument mit rotierbaren Endeffektoren

Medical instruments are provided having end effectors (22,24) and end effector actuator apparatus which are rotatable relative to the end effectors. The instruments generally include a tube (20) which is typically coupled to the end effectors via a clevis around which the end effectors pivot, a push rod (60) extending through the tube and coupled to the end effectors, and an actuator apparatus engaging the tube and the push rod with the actuator apparatus including a handle (85) which surrounds and rotatably engages the proximal end of the tube, and a lever arm (75) which pivotally engages the handle and is coupled to the push rod such that pivotal movement of the lever arm relative to the handle effects axial movement of the push rod relative to the tube and pivotal movement of the end effectors. In order to alternatively fix or allow rotation of the actuator apparatus relative to the tube and end effectors, the tube is provided with a plurality of peripherally spaced apart recesses (330) in a portion thereof, and the handle is provided with a resiliently biased contact element (300) which is coupled to an electrode (99) and which when seated in a recess restrains rotation of the outer tube about the longitudinal axis, but which can be unseated by a sufficient relative rotational force. To decouple rotation of the push rod from the lever arm, a generally spherical push rod engaging element (190) is provided in a cylindrical bore (200) of the lever arm.