A surgical cutting instrument (3) having a proximal end (4), a distal end (5), opposing sides (6, 7), and a longitudinal axis (8) and comprising: (i) an instrument body (2)； (ii) a pivotal cutting arm (10) having a pinion (20) with an axis of rotation, the pinion being integrally formed with the pivotal cutting arm, wherein the pivotal cutting arm is mounted for rotation relative to the instrument body about a pivot axis (11), the pivot axis being the axis of rotation of the pinion, so that, rotation of the pinion about the pivot axis, causes the pivot arm to pivot relative to the instrument body； (iii) a cutting blade (40) on the pivotal cutting arm for resecting tissue； (iv) a rack (25) that can be moved in a reciprocating linear motion forward towards the distal end and rearwards toward the proximal end, the rack and the pinion being meshed together to forming a rack and pinion mechanism so that linear motion of the rack effects pivotal movement of the pivotal cutting arm about the pivot axis. This provides a very simple yet robust device which can have a minimum cross-section. It can thus be used for minimally invasive procedures such as cutting material from the interior of a spinal disc.
