Abstract: The invention related to an instrument for cutting biological and notably human tissue, especially during endoscopic surgery, with an outer tube and a hollow, cylindrical cutting tube which is positioned within the outer tube and can be rotated about its longitudinal axis and at whose distal end at least one blade is positioned. The instrument also comprises a manipulator which is mounted at the proximal end of the tubes. The outer tube can be displaced in the axial direction of the cutting tube, which is immovably fixed to the manipulator, against the force of a pressure spring between an initial position in which the outer tube projects beyond the cutting tube on the distal side and a working position in which the blade protrudes from the distal end of the outer tube. The aim of the invention is to improve an instrument of this type in such a way that it is simple and safe to use while giving an operator the greatest possible freedom of movement.

Abstract: The invention relates to an instrument for cutting biological and notably human tissue, especially during endoscopic surgery, with an outer tube (2) and a hollow, cylindrical cutting tube (3) which is positioned within the outer tube (2) and can be rotated about its longitudinal axis (7) and at whose distal end at least one blade (5) is positioned. The instrument also comprises a manipulator (4) which is mounted at the proximal end of the tubes (2, 3). The outer tube (2) can be displaced in the axial direction of the cutting tube (3), which is immovably fixed to the manipulator (4), against the force of a pressure spring (16) between an initial position in which the outer tube (2) projects beyond the cutting tube (3) on the distal side and a working position in which the blade (5) protrudes from the distal end of the outer tube (2).