Arthroscopic surgical instruments

An arthroscopic surgical instrument includes a hollow tube with an actuator coupled to its proximal end and an end effector coupled to its distal end. The actuator and the end effector are coupled by a cylindrical push rod which passes through the hollow tube. The push rod includes a frangible link in the form of a flattened portion with strength reducing semicircular side cuts which breaks when a predetermined force is applied to the end effector by the actuator. The end effector includes a stationary jaw and a movable jaw. The stationary jaw is coupled to the distal end of the tube and receives the push rod. The movable jaw is coupled to push rod and is pivotally coupled to the stationary jaw by arcuate engaging surfaces on both jaws. The movable jaw is also provided with a pair of serrated knife-like edges with an inner concave surface between them and the stationary jaw is provided with a receiving opening into which the movable jaw fits when the jaws are in a closed position. The receiving opening is defined by a pair of side walls having an upper taper which terminates in a sharp edge and a distal end wall having a concave inner surface. The concavity of the inner surface of the end wall is defined by a radius from the axis of rotation of the movable jaw. An electrical connection to the hollow tube is provided for supplying the jaws with a cautery current.