A surgical instrument for grinding the cotyloid cavity includes an instrument head and a drive shaft. In order to offer easier access during a minimally invasive operation, the drive shaft, which can include an optionally provided shank, is located at an angle with respect to the rotation axis of the instrument head. In order to facilitate the alignment of the instrument head and the exertion of the advancing force, a handle can be provided that is located in the direction of the rotational axis of the instrument head but is connected to the instrument head or to the shank at a location outside of the rotational axis.