A medical cutting instrument for cutting muscles and tendons, having a shaft on whose distal end a tool is mounted consisting of two jaw members, such that one jaw member can be moved with respect to the other jaw member, and on whose proximal end a handle is mounted, such that the movable jaw member and the handle operatively interact by way of an actuation element, in such a way that the movable jaw member can be shifted by actuating the handle between a closed position and an opened position. The other jaw member is U-shaped such that the two parallel legs of the U are disposed diagonally to the instrument longitudinal axis and the opening of the U points toward one side of the other jaw member, so that the other jaw member can be pushed from the side onto the muscle/tendon tissue that is to be severed.
