Abstract: A surgical instrument comprises a first member extending distally from a proximal end and having an opening in a distal region for admitting tissue, and a second member disposed within the first member for moving a cutting implement and causing it to cut tissue that is exposed to the implement through the opening. A knob is attached to the proximal end of the first member and is mounted in rotatable engagement with a hub of the instrument to rotate the first member and selectively change a rotational orientation of the opening with respect to the hub. The knob is axially movable with respect to the hub to a locked position in which the knob nonrotatably engages the hub.

Abstract: A surgical instrument includes a plastic hub which is received by a handpiece for operating the instrument. The plastic hub includes a wall that encloses a passage that receives a surgical tool-carrying member, and at least one detectable coding element is embedded at a selected circumferential position in the wall. For example, the coding element is embedded in a hole disposed in the wall. Alternatively, the coding element is molded into the wall during injection molding of the hub. The coding element is, for example, a magnet.