A prosthetic acetabular cup inserter and impactor has a body, a cup engaging element disposed at a first end of the body which is adapted to engage an inner surface of a cup with which it is used. An operating system is adapted to axially rotate the cup engaging element in relation to the body in use. An impaction plate that is adapted to engage an undulating rim of the cup is disposed between the body and the cup engaging element. The impaction plate is connected to the operating system by a linkage which acts to axially rotate the impaction plate in unison with the cup engaging element in use.
