Acetabular cup reamer guide

A combination of an acetabular cup reamer (1) and a guiding instrument (5), which comprises:

• an acetabular cup reamer (1) comprising a stem (2) and a reaming element (3) wherein the reaming element (3) is fixed rigidly to the end of the stem (2) and has a roughly hemispherical shape and wherein the stem (2) comprises a hinge (10), which allows movement of the end of the stem in a different orientation with respect to the reaming element (3);
• and
• a guiding instrument (5) comprising one or more contact elements (6), wherein two or more of said contact elements (6) form larger contact surfaces extending over specific areas of the bone surrounding the acetabular cup implant zone in at least three contact points, wherein the one or more contact elements (6) are designed such that the angle between the plane through the central axis (Y) of the circle formed by the acetabular rim and one contact point and the plane through the central axis (Y) and the adjacent contact point is never greater than 180° and, upon contacting said areas of the bone surrounding the acetabulum, ensure a tight fit of said guiding instrument (5) on said bone;
• and
• one or more connecting elements (7) which reversibly connect the reamer (1) to the guiding instrument (5), which allow a free rotation of the reamer (1) around its longitudinal axis.