A surgical cutting instrument comprising: an inner tube having a distal end and a proximal end, the inner tube including a cutting surface at the distal end and a flexible portion located between the distal end and the proximal end; an outer tube having a distal end and a proximal end, the outer tube including a cutting window at the distal end and a flexible portion located between the distal end and the proximal end, the inner tube being disposed within the outer tube so as to align the cutting surface of the inner tube with the cutting window of the outer tube; a semi-rigid tube disposed around at least the flexible portion of the outer tube and having a distal end and a proximal end, the semi-rigid tube comprising a plurality of links disposed around at least the flexible portion of the outer tube, the links including a male portion and a female portion, the male portion being insertable into the female portion of an adjacent link; a distal compression bearing that is provided on the outer tube at a position that is adjacent to the distal end of the outer tube, the distal compression bearing radially protruding from an outer surface of the outer tube; and a compression member that is movably attached to the outer tube at a position that is proximal to the proximal end of the semi-rigid tube, the semi-rigid tube being disposed between the compression member and the distal compression bearing, the compression member being distally movable relative to the outer tube to provide a compression force to the semi-rigid tube between the compression member and the distal compression bearing so as to compress the plurality of links together and rigidly lock the semi-rigid tube, the outer tube and the inner tube at a user-selectable predetermined bend angle, the compression member being proximally movable relative to the outer tube to release the compression force from the semi-rigid tube and thereby return the semi-rigid tube, the outer tube and the inner tube to an unlocked state. an inner tube having a distal end and a proximal end, the inner tube including a cutting surface at the distal end and a flexible portion located between the distal end and the proximal end; an outer tube having a distal end and a proximal end, the outer tube including a cutting window at the distal end and a flexible portion located between the distal end and the proximal end, the inner tube being disposed within the outer tube so as to align the cutting surface of the inner tube with the cutting window of the outer tube; a semi-rigid tube disposed around at least the flexible portion of the outer tube and having a distal end and a proximal end, the semi-rigid tube comprising a plurality of links disposed around at least the flexible portion of the outer tube, the links including a male portion and a female portion, the male portion being insertable into the female portion of an adjacent link; a distal compression bearing that is provided on the outer tube at a position that is adjacent to the distal end of the outer tube, the distal compression bearing radially protruding from an outer surface of the outer tube; and a compression member that is movably attached to the outer tube at a position that is proximal to the proximal end of the semi-rigid tube, the semi-rigid tube being disposed between the compression member and the distal compression bearing, the compression member being distally movable relative to the outer tube to provide a compression force to the semi-rigid tube between the compression member and the distal compression bearing so as to compress the plurality of links together and rigidly lock the semi-rigid tube, the outer tube and the inner tube at a user-selectable predetermined bend angle, the compression member being proximally movable relative to the outer tube to release the compression force from the semi-rigid tube and thereby return the semi-rigid tube, the outer tube and the inner tube to an unlocked state.