The equipment has a base frame (1) having a guiding plate and a laterally protruding primary gage, a fastening device on the bone, and a curved milling gage (7) having a main body (70) and a guiding piece, which is moved along a curved guiding path relative to the main body and has a receptacle for an abrasive tool. The aligning devices (17,77) place the curved milling gage in a clearly defined relative position when the curved milling gage is inserted into the base frame.