A surgical cutting instrument having an elongated rotatable inner member provided with a cutting edge at its distal tip, the inner member adapted to rotate within an elongated outer tube having a window adjacent its distal end adapted to cooperate with the cutting edge of the inner member. The outer tube is provided with a portion thereof adjacent its distal end which enables the distal tip of the outer tube to be bent at an angle relative to the proximal portion of the outer tube. The outer tube may be bent by a user into a selected angular position with the aid of a tool calibrated in a plurality of discrete positions. The tool is adapted to enable the outer tube to be rotated to any selected position prior to being bent so that the window at the distal tip of the outer tube may be caused to face in any desired direction relative to the bend in the outer tube.