An acetabular cup shell insertion system is provided for a shell having a threaded central opening and a part-spherical inner surface. The system includes an impactor having a strike plate at a first end and a first connection element at a second end. Also provided is a longitudinally extending adapter having a threaded first end adapted to threadably engage the threaded central opening in the acetabular cup. A second end of the adapter has a second connection element for engaging the impactor first connection element. An impaction flange extends radially outwardly of a longitudinal axis of the adapter. The flange has a first contact surface facing the second end of the adapter. A second contact surface surrounding the threaded first end of the adapter contacts the part-spherical inner surface of the acetabular cup surrounding the threaded central opening.
