Abstract: A surgical cutting instrument with a tubular member provided with a plurality of markings (for example, depth markings) to aid a surgeon in assessing the dimensions (for example, the depth) of the tissue or structure that is cut or shaped. The tubular member may be an outer tubular member of a cutting instrument having a proximal end and a distal end. An inner tubular member having cutting means may be rotatably disposed within the outer tubular member. The cutting means or cutter may be rotatably disposed within the outer tubular member adjacent to an outer cutting aperture and adjacent the plurality of markings.