US Patent 7041107 Instrument

An instrument for shaping a mouth part of a drilled tunnel provided in a bone. The instrument includes a shaft having a longitudinal axis and a first and a second end. The first end of the shaft is provided with a projection, which includes a blade for shaping the mouth part of the drilled tunnel when the instrument is turned around the longitudinal axis of the shaft. The instrument is asymmetric at an intersecting surface perpendicular to the longitudinal axis and intersecting with the blade, the instrument thus shaping the surfaces surrounding the first end only substantially within an area corresponding with a turning angle of such a turning movement.